ADAPTATIONS, GENETIC VARIATION

AND NATURAL SELECTION

Seventh Grade

Piloted at West Hawaii Explorations

Academy

(WHEA)

By:

Leayne Patch-Highfill and Jessica Schwarz

PRISM UHH GK-12 Program

ADAPTATIONS, GENETIC VARIATION AND NATURAL SELECTION GRADE LEVEL: Seventh Grade PURPOSE: This curriculum was designed to communicate concepts about evolutionary processes to seventh grade students. Hawaii is home to many endemic species that exhibit different genetic variations. These unique species are excellent examples to utilize to help students understand evolution. STANDARDS/BENCHMARKS: Standard 1: The Scientific Process: SCIENTIFIC INVESTIGATION: Discover, invent, and investigate using the skills necessary to engage in the scientific process Benchmark SC.7.1.1 Design and safely conduct a scientific investigation to answer a question or test a hypothesis Benchmark SC.7.1.2 Explain the importance of replicable trials Benchmark SC.7.1.3 Explain the need to revise conclusions and explanations based on new scientific evidence Standard 3: Life and Environmental Sciences: ORGANISMS AND THE ENVIRONMENT: Understand the unity, diversity, and interrelationships of organisms, including their relationship to cycles of matter and energy in the environment Benchmark SC.7.3.2 Explain the interaction and dependence of organisms on one another Standard 5: Life and Environmental Sciences: DIVERSITY, GENETICS, AND EVOLUTION: Understand genetics and biological evolution and their impact on the unity and diversity of organisms Benchmark SC.7.5.2 Describe how an inherited trait can be determined by one or more genes which are found on chromosomes Benchmark SC.7.5.3 Explain that small differences between parents and offspring could produce descendants that look very different from their ancestors Benchmark SC.7.5.4 Analyze how organisms' body structures contribute to their ability to survive and reproduce Benchmark SC.7.5.6 Explain why variation(s) in a species' gene pool contributes to its survival in a constantly changing environment RATIONALE: The Hawaiian Island chain is the most isolated archipelago on the planet. This isolation has limited the number of animal and plant species that have arrived here naturally. When organisms do colonize the islands successfully, their populations must change over time in order to suit the conditions of their new environment. As a result of millions of years of evolution in isolation, the Hawaiian Islands are home to many fascinating endemic species, such as Hawaiian honeycreepers, Happy-face spiders, and Ohia trees.

This curriculum focuses on examples of Hawaii’s native flora and fauna to understand evolutionary concepts, including genetic variation, natural selection, and adaptation. Additional reading material developed by Full Option Science System (FOSS) at the Lawrence Hall of Science is included for each topic. Background information is included at the beginning of each lesson, but more detailed information with added examples from FOSS is included for added teacher support. This unit can be used as supplemental teaching materials with the FOSS Populations and Ecosystems Course, lessons Adaptations, Genetic Variation and Natural Selection. LESSONS PLAN: This unit was designed to last from 8-9 weeks, depending on the total number of field trips taken or how long it takes to complete “Build a Hawaiian Bird”. Most lessons can be completed within a 45-minute class period, but some lessons need several weeks to be completed. Lessons that include a field trip take the entire school day. Depending on the number of science classes taught each week, the duration of this unit will vary. Due to complex topics, students may need extra time to review concepts before starting lessons, which will also affect the duration of this unit. Although the topics are introduced in a particular order and the unit is designed to flow well, the lessons can be used out of context or used individually to address specific concepts. All lesson plans start with a summary of the lesson and a list of objectives students will learn. Lessons also include detailed materials lists as well as instructions for teacher preparation at the beginning of each lesson. The instructor should scan these lists prior to beginning of each lesson since materials must be purchased (some ordered), hand-outs should be Xeroxed, and field trips must be organized. Background information is also included with each lesson for the instructor and vocabulary words that can be used for vocabulary or spelling lessons are introduced here as well. Week 1: Students are introduced to the concepts of adaptations, (founder species, endemism, adaptive radiation, Hawaiian honeycreepers, Hawaii as an archipelago, etc.) and a verbal pre-assessment of what the students already know about the topic is conducted. Students can be given background information on Adaptations before the start of the first lesson and this could also be discussed. The students then learn about particular adaptations Hawaiian birds have in order to survive and study a poster of different bird bills. They then engage in a hands-on Hawaiian Bird Beak Adaptation Lab to simulate how birds have particular beak shapes to acquire different food sources. Week 2: If applicable, students will explore different bird habitats on a field trip. In this unit, students visited Puu waa waa Forest Bird Sanctuary. Other ideas for field trips could be Hawaii Volcanoes National Park, Kaloko-Honokohau National Park or Kipuka 21 on Saddle Road. Students will observe different adaptations birds have in order to survive in their respective habitat. If a field trip is not possible, a classroom simulation of a bird habitat could be created. After the field trip, students will write a paper about a Native Hawaiian Forest Bird.

Week 3-4 (could last to week 5): Students get creative and apply what they have learned in prior weeks with “Build a Hawaiian Bird”. They first develop a bird from paper cut-outs provided. After the model is completed, the bird is then constructed using papier mache. The actual building of the birds can take several weeks depending how detailed the birds become. After the birds are completed, students write a paper describing their bird and its specific adaptations. Each bird should also be presented to the class. Week 5: Students are introduced to the subject of Genetic Variation. Genetics can be a confusing concept for students, having students read the background material provided helps with complex vocabulary. After discussing the reading material, students play Vocabulary Bingo to get more comfortable with the topic. If more review is needed, a vocabulary review is also provided. Students then study human traits in the lesson, “Exploring Human Traits” where they survey their own traits. Week 6: Students will learn how genes are passed from generation to the next by studying Happy-Face Spiders. They will act as captive breeders and choose traits to breed that are beneficial for survival. Punnet squares will also be introduced. Week 7: After students have a solid understanding of adaptations and genetic variation they are introduced to the topic of Natural Selection. They participate in a natural selection simulation in which they create and modify “paper airplanes” over several generations to see how favorable heritable traits are passed on. Week 8: Students get another chance to get out of the classroom with a field trip to the Ohia Common Garden in Volcano. Ohia from different elevations have morphological differences and students get a chance to observe this phenomenon. After the trip to the garden, students write a reflection about their field trip.

CONCEPT MAP:

FORMATIVE ASSESSMENT: The level at which the students understand the topic will assessed throughout the lessons. Each lesson will begin by asking the students what they already know or recall about the topic. At the end of each lesson the students are asked to come up with three concepts they learned during the lesson. At the beginning of the next lesson the previously learned concepts will be re-visited. After the Hawaiian Bird Beak Adaptation lab, students will take a field trip to different bird habitats to see how birds use their adaptations in the wild. After this field trip, students write a scientific report on a Hawaiian bird of their choice. Students will be given background reading material on genetic variation for homework in order to discuss the topic. The next lesson will begin answering questions about the reading material and vocabulary will be assessed with vocabulary bingo. Prior to visiting the Ohia Common Garden, the students will be introduced the concept of Natural Selection by talking about Ohia and phenotypic plasticity. Before meeting with the guest speakers, students were able to ask questions to clear up any misconceptions. The students will then write a reflection about their visit to the garden. SUMMATIVE ASSESSMENT: These students will not have one final assessment project; rather they will have summative assessments at the end of each topic. They will be assessed of their knowledge of adaptations with the activity “Build a Hawaiian Bird”. They choose adaptations that will be beneficial for the birds’ survival and reproduction. Students follow with written reports explaining the scientific name given to the birds, the adaptive

advantages of their features, and how the birds are adapted to their environments. Finally, students improve their communication skills by giving oral presentations on their project. After learning about genetic variation of Happy-face spiders, students will choose the color of spider they would use to breed so the spider can survive in the wild. They then color a picture of a Happy-face spider using the colors they chose to breed. They will continue to improve on communication by presenting their pictures to the class and defending their selection. Finally, after studying natural selection, the student will write a reflection about their trip to the Ohia Common Garden and Hawaii Volcanoes National Park. This unit was developed and piloted by Leayne Patch-Highfill and Jessica Schwarz

at West Hawaii Explorations Academy (WHEA).

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Hawaiian Bird Beak Adaptation Lab Summary Students will be introduced to the different types of bird beaks that Hawaiian birds have developed as adaptations to the different habitats in which they live. They will use tools that represent different beaks to learn which beak is better adapted to collect different food types in a certain amount of time. Objectives

• Students will examine the relationship between a bird’s beak and its ability to find food and survive in a particular habitat.

• They will understand that Hawaiian birds have adapted physically to their food sources.

• Students will learn about different Hawaiian birds. • Students will explore which beaks are more efficient for collecting foods

by experimenting with different tools representing different beak types. • Students will represent their data using bar graphs. • Students will recognize the importance of multiple trials.

Materials Plastic cups to represent bird stomach-will need one for each student Beak materials: 5-6 sets of chopsticks, 1 turkey baster, 1 nut cracker, 2 pliers, 4 tweezers, 2 medicine droppers, 1 Clothes pin, 2 rulers, 3 plastic spoons, 1 slotted spoon,1 long snapping hair clip, 1 small hand strainer, and 3-4 straws to hold marshmallows and one straw for nectar Food Materials: Gummy worms, sunflower seeds, rice, small berries or sweet tart candies, marshmallows, Swedish gummy fish, oreo/graham cracker cookie crumbs (to represent soil), small twigs, water colored with food dye (can use clear if easier). Three plastic graduated cylinders 2 Cookie Sheets or pans for sunflower seeds and rice Plastic container to hold “soil” and worms Bowls for holding water Pictures of Birds Bird Beaks Record Sheet (see below) Challenge cards for each station (see below) Teacher Prep for Activity

• Make challenge cards (cut and paste from list below) to put at each station-can be made on card stock and laminated, so they can used again. The challenge cards state the scenario for each station.

• Xerox “Adaptations” reading and data sheet provided • Set up 8 work stations: 1 for each type of food source represented. Place

the 3 different types of tools for each station. Station #1: Bird: Ae’o

Food Source: Gummy worms buried in cookie crumbs Tools: chopsticks, turkey baster, nut cracker

Station #2: Bird: Palila Food Source: String beans and sunflower seeds scattered on cookie sheet Tools: pliers, chopsticks, tweezers

ADAPTATIONS Concepts Endemic Hawaiian birds are unique to Hawaii because they are only found here. Founder species that came to Hawaii were isolated for millions of years, and they had to physically adapt in order to survive in their new environments. Many Hawaiian birds, such as Hawaiian honeycreepers have different beak length and sizes in order to obtain food in their habitats. Standards addressed 7.1.1, 7.1.2, 7.5.4 Duration 60 minutes Vocabulary Endemic Founder species Hawaiian honeycreepers Adaptive radiation Source Material Adapted from sciencenetlinks.com & www.eduref.org

PRISM UHH GK-12

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Station #3: Bird: I’iwi Food Source: Colored water in a graduated cylinder (one for each student) Tools: Medicine dropper, straw (don’t suck up, use finger to stop the liquid), pliers

Station #4: Bird: Elepaio Food Source: Rice spread out on cookie sheet (to represent insects) Tools: Tweezers, clothes pin, medicine dropper

Station #5: Bird: Nene Food Source: Small berries and grass (round sweet tarts work well too) Tools: 2 rulers held together, chopsticks, spoon

Station #6: Bird: Albatross Food Source: Swedish gummy fish Tools: Chopsticks, long snapping hair clip, spoon

Station #7: Bird: Koloa or Hawaiian Duck Food Source: Small twigs in a bowl of water Tools: Slotted spoon, tweezers, hand strainer

Station #8: Bird: ‘Io or Hawaiian Hawk Food Source: Marshmallows (skewered on a straw) Tools: Chopsticks, tweezers, spoon

• Place each challenge card and picture of corresponding bird at every station Background Over time, animals change in order to fit the needs of their environment. The Hawaiian Islands are the most isolated archipelago on the planet, and due to millions of years of isolation, only a small amount of animals and plants have arrived here. Species arrived on the islands by only three modes of transportation: wind, waves, and wings (the “three Ws”). All plant and animal species that are native or endemic to Hawaii descended from a small community of founder species. Hawaiian rain forests are home to several endemic species, such as Hawaiian birds and these species are unique to the islands. Most endemic forest birds belong to a group of birds known as Hawaiian honeycreepers. Scientists think all the honeycreepers evolved from a single finch species that colonized the islands 15 million years ago. Hawaiian endemic birds evolved and radiated into new species after they arrived to the islands from somewhere else. This is a process called adaptive radiation, which has resulted in many different honeycreepers adapted to various environments. One characteristic that can distinguish Hawaiian honeycreepers apart are their diverse bill shapes and lengths. There are also non-honeycreepers, such as a species of Flycatcher (the Elepaio) and a species of Hawk (the ‘Io) that are also endemic to Hawaii. All birds have different beak shapes and sizes depending on what the bird eats and where that food is found. A bird’s beak is basically a lightweight, bony extension of the skull. Bird beaks are multi-functional tools used to gather and capture food, build nests, groom feathers and attack competitors. Procedure 1) First have students read background information about Adaptations (Information follows)-this can be done in class or have students read the information for homework or the instructor can lecture on the material. 2). After students have completed the readings, ask the students what they know about adaptations. Explain that Hawaii is the most isolated archipelago in the world and how animal and plant species arrived here. Be sure the students understand species, such as Hawaiian honeycreepers filled different niches throughout Hawaii and adapted to their specialized habitats. Have them explain what it means if a species is endemic or indigenous. Pick at least three concepts that you will want the students to really remember such as; What is adaptive radiation? What will happen if a species will not adapt to environment? or What will happen if a habitat changes? 3). Divide students into groups of three (one tool per student). If there are more students, add another station, or divide groups into four and have one of the students be responsible for timing the other students and writing down data. Have the students repeat what they did, but have the student who was the scorekeeper trade out with another student. Also, each student will keep the same beak throughout the lab. They should improve as they go along. 4). Have students go to their assigned station and have them read their challenge card. 5). Pass out record sheet.

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6). Have each student write down a prediction on the worksheet provided. 7). Each student will be given 20 seconds to gather as much food as they can with the “beak” (tool) they have. They will put the food into their “stomach” (cup). 8). When the teacher says “Stop”, students empty their stomachs and count the number of items they collected. Record this amount on the Bird Beaks Record Sheet. 9). Repeat the trial 3 times and be sure students empty their stomachs after each round and record amount on their worksheet. 10). Students calculate the average amounts for each beak type and have each group construct a bar graph of their averages for each station. The three different bird beaks should be on the X axis and the average amount of food collected should be on the Y axis. (See sample bar graph below). Amount of Food Beak 1 Beak 2 Beak 3 Teacher Resources for this activity Challenge Cards: Challenge #1-You have been given gummy worms (to represent worms) as your food source. You have also been given sample beaks: 1) Chopsticks, 2) Turkey Baster, and 3) Nut cracker. Your challenge is to obtain as many gummy worms as you can that are buried in the soil within 20 seconds. Put your food in your stomach (cup). Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Challenge #2-Your have been given sunflower seeds (to represent seeds) as your food source. You have also been given sample beaks: 1)Pliers, 2) Chopsticks, and 3) Tweezers. Your challenge is to use each beak to crack the shell and remove the seed inside within 20 seconds. Put your food in your stomach (cup). Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Challenge #3-You have been given colored water (to represent nectar) in a graduated cylinder. You have also been given sample beaks: 1) Medicine dropper, 2) Straw, and 3) Pliers. Your challenge is use each beak to see how much water you can transfer to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Challenge #4-You have been given rice (to represent insects) as your food source. You have also been given sample beaks: 1) Tweezers, 2) Clothes Pin, and 3) Medicine Dropper. Your challenge is to use each beak and transfer as many pieces of rice to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Challenge #5-You have been given small berries or sweet tart candies that llok like berries as your food source. You have also been given sample beaks: 1) 2 rulers held together, 2) Chopsticks, and 3) Spoon. Your challenge is to use each beak and transfer as many berries to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Challenge #6-You have been given Swedish gummy fish (to represent fish) as your food source. You have also been given sample beaks: 1) Chopsticks, 2) Long snapping hair clip, and 3) spoon. Your challenge is to use each beak and transfer as many fish to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet.

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Challenge #7-You have been given small twigs (to represent small invertebrates) in water as your food source. You have also been given sample beaks: 1) Slotted spoon, 2) Tweezers, and 3) Small hand strainer. Your challenge is to use each beak and transfer as many twigs to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Challenge #8-You have been given Marshmallows on a straw (to represent small mammal) as your food source. You have also been given sample beaks: 1) Chopsticks, 2) Tweezers, and 3) Spoon. Your challenge is break apart the marshmallows and transfer as many marshmallows to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet. Assessments Journal writing Bird Beak Data Sheet Build a Hawaiian Bird Lesson Extensions If time prevails, students can switch stations after the first 3 trials and learn about different beak adaptations. If this is the case, then the worksheet should be extended to add more columns. Also, take students on a field trip to different habitats where native birds might be found. For example, students could visit a rain forest such as Volcanoes National Park to see native birds such as the ‘Omao, Apapane and Hawaii Amakihi. Students could also visit a mesic forest like Pu’u Wa’a Wa’a Forest Bird Sanctuary and observe birds like Akepa and Elepaio and in the Dry Land Forest of Pu’u Wa’a Wa’a students may see Nene. If time prevails, take students on another field trip to a habitat that is completely different from the first one they visited. A second field trip could be to the coastline, such as Kaloko-Honokohau National Historical Park for example. Students may see Ae’o and the Hawaiian Coot. It would be ideal if students had binoculars and field guides to see the birds up close. Discuss with students why birds live in different habitats (be sure to notice different food sources within each habitat). Ask what adaptations the birds have in order to survive in each of the habitats. This would be a good time to get the students thinking about what types of questions they could ask in order to conduct a scientific investigation in the feild. For example, “How many invertebrates does an Ae’o collect in a certain amount of time”? How would they set that experiment up and how would they conduct it? They can write about it in a journal entry. If a field trip is not possible, create a class simulation of a field trip. Before the students come to class, transform your classroom into a natural habitat. Get pictures of birds and plants that represent a particular habitat and hang on wall or an area of your choice. When the students come to class, explain to them which habitat they just encountered and have them walk around to see the different bird and plant pictures. Audio with bird songs could help improve this simulation. For ideas about forest habitats, the following website is a good start (pgs 7-11): http://www.state.hi.us/dlnr/dofaw/kids/teach/forest%20activity%20guide.pdf They can still use field guides and come up with questions that would be suitable for field research. Great field guides to use as references on bird watching and plant identification are: A pocket guide to Hawaii’s birds, H.D. Pratt and J. Jeffrey (~$9.00) A pocket guide to Hawaii’s trees and shrubs, H.D. Pratt (~$10.00) Resources http://www.eduref.org/cgi-bin/printlessons.cgi/Virtual/Lessons/Science/Animals/ANM0016.html www.sciencenetlinks.com/pdfs/birdbeaks_actsheet.pdf http://www.hear.org/hoike/ http://www.esi.utexas.edu/outreach/gk12/docs/lessons/birdBeak.pdf Foss-Populations and Ecosystems

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My Food Source is ___________________________________________________.

My Bird is __________________________________________________________. Prediction: I think that ________________________________________________

___________________________________________________________________

___________________________________________________________________

Data Table

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Draw a bar graph that shows the average amount of food gathered by the three types of beaks.

Amount of Food

Beak 1 Beak 2 Beak 3

Bird Beaks Record Sheet

Name:_________________________

Beak 1: Beak 2: Beak 3: Trial 1 Trial 2 Trial 3 Average (Total/3)

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Photo: en.wikipedia.org/wiki/RecAurvirostridae

Hawaiian Black-necked Stilt

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Photo: J. Jeffrey

Photo: J. Jeffrey

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Photo: P. Latourrette

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Photo: www.americanparknetwork.com

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Hawaiian Goose

Photo: www.pbase.com/jpkln/image/54126096

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Laysan Albatross

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Hawaiian Duck

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Photo: R. Decker

Hawaiian Hawk

Challenge # 1 -You have been given gummy worms (to represent worms) as your food source. You have also been given sample beaks: 1) Chopsticks, 2) Turkey Baster, and 3) Nut cracker. Your challenge is to obtain as many gummy worms as you can that are buried in the soil within 20 seconds. Put your food in your stomach (cup). Repeat each trial 3 times and record the amount of food after each trial on your worksheet.

Challenge #2-Your have been given sunflower seeds (to represent seeds) as your food source. You have also been given sample beaks: l)Pliers, 2) Chopsticks, and 3) Tweezers. Your challenge is to use each beak to crack the shell and remove the seed inside within 20 seconds. Put your food in your stomach (cup). Repeat each trial 3 times and record the amount of food after each trial on your worksheet.

Challenge #5-You have been given small berries as your food source. You have also been given sample beaks: 1) 2 rulers held together, 2) Chopsticks, and 3) Spoon. Your challenge is to use each beak and transfer as many berries to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet.

Challenge #6-You have been given Swedish gummy fish (to represent fish) as your food source. You have also been given sample beaks: 1) Chopsticks, 2) Long snapping hair clip, and 3) spoon. Your challenge is to use each beak and transfer as many fish to your stomach in 20 seconds. Repeat each trial 3 times and record the amount of food after each trial on your worksheet.

Extensions Take students on a field trip to different habitats where native birds might be found. Students can observe birds in the wild and they can also record what birds they will see in different environments. For example, if you live on the Big Island, students could visit a rain forest such as Volcanoes National Park to see native birds such as the ‘Omao, Apapane and Hawaii Amakihi. Students could also visit a mesic forest like Pu’u Wa’a Wa’a Forest Bird Sanctuary and observe birds like Akepa and Elepaio and in the Dry Land Forest of Pu’u Wa’a Wa’a students may see Nene. If time prevails, take students on another field trip to a habitat that is completely different from the first one they visited. A second field trip (on the Big Island) could be to the coastline, such as Kaloko-Honokohau National Historical Park for example. Students may see Ae’o and the Hawaiian Coot. It would be ideal if students had binoculars and field guides to see the birds up close. If you live on neighboring islands, bird habitats are accessible as well. On Maui, native forest birds can be found at Hosmer Grove in HaIeakala National Park and water birds can be found at Kealia National Wildlife Refuge. On Oahu, seabirds can be seen around Makapu’u Point and some native forest birds might be seen near Lyon Arboretum. On Kauai, Kokee State Park is a great place to see native forest birds and Kilauea Point National Wildlife Refuge is a great environment to see different species of seabirds and Nene. If you don’t have the opportunity to visit a habitat that has native birds, students can observe non-native birds just about anywhere. All birds use certain adaptations to survive so observing any type of bird will be beneficial. Discuss with students why birds live in different habitats (be sure to notice different food sources within each habitat). Ask what adaptations the birds have in order to survive in each of the habitats. This would be a good time to get the students thinking about what types of questions they could ask in order to conduct a scientific investigation in the field. For example, “How many invertebrates does an Ae’o collect in a certain amount of time”? How would they set that experiment up and how would they conduct it? They can write about it in a journal entry. If a field trip is not possible, create a class simulation of a field trip. Before the students come to class, transform your classroom into a natural habitat. Get pictures of birds and plants that represent a particular habitat and hang on wall or an area of your choice. When the students come to class, explain to them which habitat they just encountered and have them walk around to see the different bird and plant pictures. Audio with bird songs could help improve this simulation. For ideas about forest habitats, the following website is a good start (pgs 7-11): http://www.state.hi.us/dlnr/dofaw/kids/teach/forest%20activity%20guide.pdf They can still use field guides and come up with questions that would be suitable for field research. Great field guides to use as references on bird watching and plant identification are: A pocket guide to Hawaii’s birds, H.D. Pratt and J. Jeffrey (~$9.00) A pocket guide to Hawaii’s trees and shrubs, H.D. Pratt (~$10.00) Resources http://www.hawaiiaudubon.com/birding/ FOSS-Populations and Ecosystems

West Hawaii Explorations Academy Public Charter School

Developing an Outline

Title: Short Description of what the paper is about.. .not Topic Paper!

Topic: Native Hawaiian Forest Birds

Major Point 1 : Description of Organism (including scientific name and significant adaptations)

Major Point 2: Description of Habitat

Major Point 3 : Description of Negativepositive Human Impact (Origin and nature of threats to organism/habitat/efforts to preserve/conserve organisrnlhabitat)

Conclusion: Summarize three main points, state opinion and importance of this topic.

Topic sentence:

Opening Paragraph:

Major Point 1 :

*

Rev. 411 012007

West Hawaii Explorations Academy Public Charter School

Major Point 2:

Major Point 3:

Bibliography : Must be in proper format (separated by type, alphabetized and including the necessary information) and include three sources where you found the information cited in the body. Do Not Use .corn, unless previously approved by advisor. Paper will not be accepted if this section is not completed or is incomplete.

Example of a source cited within the body of the paper: The use of enriched food will increase the growth rate of the Omilu (Vencent,1999). 0 r According to Vencent (1999) the use of enriched food will increase the growth rate of Omilu. Or "During this study, the use of enriched food in the diet of Omilu resulted in a 22% increase in growth rate over a four month trial period," (Vencent, 1999).

Example of a source cited within a bibliography:

Bibliography Magazine Vencent, Amanda. 1999."Raising Omilu." National Geographic, Available at: www.national~eographicmagazine.com.

Author's last name, first name. (or name of organization) date. "Title(of article)." Title (of book or magazine). Place Published: Publisher. (or web address)

Book Vencent, Amanda. 1999. Aquaculture Techniques. Honolulu, Hi: Bess Press.

Website Vencent, Amanda. 1999. Enriching Food for Aquaculture.

http//www.pbs.orgiwnetlenrichingfoodforaqua/

Rev. 411 0!2007

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A POCKET GUIDE Trl *

HAWA TREES , SHWUR:?

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Included are photos of all the spectes Innst. t i k e l ~ to b p or,cnuq- tered by residents and visitors al~ke. Smqll nr,ougt~ far a backpacK, but complete enough to be a valuable Dljokshelf rpferenca, this book is the perfect addition to any nafursltst's f~brary Althrdugh t

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Aloha! Welcome to the Ahupua'a of Pu'u Wa'awa'a. The Division of Forestry & Wildlife and the Pu'u Wa'awa'a Volunteer Program are pleased to offer these trails for your enjoyment. Please observe the following guidelines so that these hails not only stay open, but so that the system may expand!

There is no trail maintenance staff. Please kokua to keep this trail clean and safe. If you encounter any litter, please pick it up. If you see any loose rocks on the trail surface, please toss them aside - mahalo! Dogs are allowed on the trail at this time. This is for your safety as well as your pet. We are working to expand the trail to include some areas for dogs on leashes.

r Please stay on the trails as indicated on the map. Absolutely NO ENTRY into the quarry area. Keep the pedestrian gate closed at Tamaki Paddock -- this area remains an active cattle ranch. Please be courteous to hikers, residents and ranchers.

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Build a Hawaiian Bird Summary After students have completed the Bird Beak Adaptation Lab and study different habitats to see how birds are adapted to different habitats in the wild, students will create imaginary birds using papier mache´. Objectives

• Students will identify and describe the advantages of bird adaptations and evaluate the importance of adaptations to birds.

• Students consider different bird adaptations required for a specific habitat. • Students will present their constructed bird to the class and will defend why

they chose their specific adaptations. Materials Paper bird parts (cut-out worksheet) DLNR free posters to as habitat reference Adaptations and advantages for bird worksheet (For teacher) Elmer’s papier-mache glue (powder form) Newspaper Glue, Scissors, Paint String to display birds Teacher Prep for Activity

• Elmer’s papier-mache art paste was used for this lesson. The paste was ordered from the following website: http://www.enasco.com/ProductDetail.do?sku=8100197J, each box costs about $2.50/box and make 4 quarts. Approximately 3-4 boxes were used for 15 large birds.

• Make Xerox copies of bird cut-outs and outline for Topic Paper • Collect newspaper • Request free bird habitat posters from DLNR:

http://www.state.hi.us/dlnr/dofaw/kids/teach/forest%20bird%20poster2.jpg Background All life forms have adaptations that allow them to survive and maintain populations. Wildlife species are adapted to the environments in which they live. Birds have many different adaptations, including beaks, feet, legs, coloration and bone type. Beaks allow different birds to acquire specific foods and their feet allow them to grasp branches or prey, or wade in water. In order for birds to be better suited to their environment, these adaptations have evolved. Many different Hawaiian forest birds have different adaptations that allow them to survive in such a unique environment. Some forest birds are known as honeycreepers and many of the honeycreepers have beaks that are shaped in order to gather food from specialized sources. For example, the ‘I’iwi has a long, curved bill that is designed to consume nectar from long, tubular, curved flowers. Also, the Palila, another honeycreeper, has a short, thick bill used to rip open mamame pods to obtain the mamane seeds inside. The `Io or Hawaiian Hawk has talons in order to grasp food items such as small birds and a sharp bill to eat its prey. The ‘Ae’o or Hawaiian Stilt has long legs so it can wade in mudflats or shallow coastal wetlands. The way that a bird looks, obtains food, or travels are all advantages for a species to physically adapt to its environment.

ADAPTATIONS Concepts Different bird species, such as Hawaiian honeycreepers are endemic to Hawaii and they have adapted to the diverse habitats found only within these ecosystems. The beak structures, leg and facial muscles of honeycreepers all give insight into their diets and how they forage for food. Standards Addressed 7.1.3, 7.3.2, 7.5.4 Duration 40-50 minutes to construct paper bird. (2) 40-50 minute class periods to construct papier mache bird. 40-50 minutes for student presentations. Source Material Adapted from Project Wild

PRISM UHH GK-12

Procedure 1).Discuss with students the different adaptations that bird’s exhibit-explain the different adaptation paper cut-outs that will be given to the students and the benefits of these adaptations. Students could also help with what cut-outs will be used. Days prior to this starting this activity ask the students to brainstorm about different adaptations that they may have already learned from the previous lessons or bring in pictures of birds. A worksheet with bird cut out will be provided, but the class could make other cut-outs. Each student should create their own bird using the paper cut-outs, but student’s can pair up to create a single bird. Our students worked together in pairs and integrated their different adaptations to create one bird. (Examples are included at the end of the lesson. We learned that the larger the size of the balloon used for the body form, the larger the bird.) 2). The teacher can either assign a specific habitat that the student will create the bird for or the students can choose the habitat themselves. For this lesson, the habitats will be the coastline and the rainforest. Students can choose adaptations from either one of the habitats or a combination of both. Inform students that they will later have to explain in a presentation why they chose certain adaptations and the benefits for those adaptations. Explain to the students that they will have a chance to design their own original bird that is adapted to a Hawaiian habitat (e.i. rain forests, dry forests, wetlands, shoreline, etc). Each student should decide: The name of their bird (they should come up with a scientific name that is representative of their created bird), what the bird will eat (nectar, insects, small mammals, invertebrates, etc.), how it moves (fly or non-flyer), it’s gender (coloration), range (does it have to travel far for food), where does it nest (in the trees, ground, burrows) and any other characteristics they may want to add. As they create their birds, they should be writing in a journal or notebook why they are choosing the specific traits since they will have to present their bird at a later time and write a paper. An outline is provided for a paper the students will write after they have completed their bird. This paper should include all the information about the bird the students think is applicable. 3). Have the students choose from the cut-outs presented to them to construct a preliminary paper bird. Have the students glue their different parts to a blank piece of paper. As they are selecting the parts they are going to use, they should be taking notes about why they chose the particular traits. They should also color their bird, since coloration in birds is important adaptation for camouflage and courtship. This might take a full class period; since it may take students time to decide which adaptations they will use. 4). Once the paper bird is constructed, they will then have the opportunity to create their paper bird using papier mache. This could also be done in other artistic techniques, such as drawing or clay. 5). Students will then be asked to present their bird to the class. They should include the name of their bird, its food sources, lifestyle, etc. They will have to describe why they chose the adaptations they used and the advantages provided by the adaptations for the habitat of the bird. 6). Once students have presented their birds, hang them from the ceiling to display their creations. Assessments Designed Bird with appropriate adaptations Written paper about their bird. Presentation Resources Project Wild-K-12 Curriculum & Activity Guide. 2002 http://www.hear.org/hoike/ http://www.state.hi.us/dlnr/dofaw/kids/teach/index.htm http://www.state.hi.us/dlnr/dofaw/kids/teach/forest%20bird%20poster2.jpg (for free posters) FOSS-Populations and Ecosytems

Teacher Resources Adaptations and advantages worksheet for teacher: Beaks: Advantage: Pouch-Like Can hold the fish it eats Long-thin Can probe in mud or shallow water for insects Pointed Can probe into bark of trees for insects, like grubs Curved Can tear solid tissue for the meat it eats Short, stout Can crack the seeds and nuts it eats Slender, long Can probe the flowers for nectar it eats Feet: Advantage: Grasping Aids in sitting on branches, roosting, and protection Long toes Aids in walking on mud Clawed Can grasp food when hunting prey Webbed Aids in walking on mud Legs: Advantage: Long, slender Aids wading Powerful muscles Aids lifting, carrying prey Long, powerful Aids running Flexor tendons Aids in perching, grasping Wings: Advantage: Large Aids in flying with prey, soaring while hunting Coloration: Advantage: Bright plumage Usually male birds, attraction in courtship, mating rituals Dull plumage Usually female birds, aids in camouflage while nesting Change of plumage- Provides camouflage protection-brown in summer, white with seasons in winter. Bone structure: Advantage: Fused bones Ground bird, does not fly Hollow bones Can fly

EXAMPLES OF STUDENT WORK

Build a Bird Kit-"Cut Out" Sheets

BUILD A BIRD KIT

Body Forms To Be Used For All Birds:

Heads:

ES l, Small ~nvwkkrcrcfc~

Tails:

e

Small insc&

West Hawaii Explorations Academy Public Charter School

Developing an Outline

Title: Short Description of what the paper is about.. .not Topic Paper!

.Topic: Forest Bird Adaptations

Introduction: introdwe main points

Major Point 1 : Description of Scientific name and reason for choosing name (Genus and species)

Major Point 2: Description of each body part and what the evolutionary purpose

Major Point 3: Explain what habitat this bird would be most successful in, give details.

Conclusion: Summarize main points Major Point 1 :

Major Point 2:

* Major Point 3 :

*

Rev. 4/4/2007

INVESTIGATION 8:

GOAL

Adaptatir duces stu . . . dents to . the conce ?pt of ad; 1, any struc an organism that helps it survive and reproduce.

OBJECTIVES TENT

ldaptatlon is any trait of an orgarusm that enhances its chances of surviving and reproduc~ng m nvironrnt

ahue is a -- - L -:-

?nt.

structure rration.

ay a fea 1.

. . . .. . -

cpressed

-:--. - < .

ems, and

S

:, characteristic, or behavior of an organism, such as eye color, fur pattern, or

lit is the w, hue is e, in an individual organism, such as brown eyes, small spots, or r migratior

Variation is the range of expression or a feature within a population, such as all the different eye colors, all the different fur patt~ I all the dates on which migration starts.

CONDUCTING INVESTIGATION! Use a multimedia simulation to investigate the adaptive value of protective coloration.

Conduct simulated predator/ prey interactions over multiple generations to investigate the effect of protective coloration on the color characteristics of a population of walkingsticks.

BUILDING EXPLANATIONS Explain how adaptations help organisms survive in an environment.

Describe how a population can change over time in response to environmental factors.

SCIENTIFIC AND HISTORICAL BACKGROUND Life is incredibly robust and indomitable. ADAPTATIONS

At the same time, however, it is sensitive Organisms have adaptations that allow and vulnerable. This apparent them to live in an environment. Sea otters contradiction is one of the many aspects of live in the sea, desert tortoises live in the life that makes its study so intriguing. desert, and mountain heather lives in the What makes life simultaneously durable mountains, The sea otter will die in the and fragile? desert or mountains as surely as the

Life resides in individual organisms. Life tortoise and heather will die in the sea.

continues as long as the basic needs of an Every kind of organism has a unique set of

organism are met. These include energy, adaptations to live in its environment.

water, gases, nutrients, space, and Adaptations are physiological attributes protection. The exact measure of each (structures and functions) or behaviors requirement and the medium in which it is that enhance an organism,s opportunity to provided vary for each kind of organism. live and reproduce in its environment. If the resources needed by a given The hawk's talons, the shark's broad tail, organism are plentiful--optimum the toad's long, sticky tongue, and the conditions-the organism will thrive. If clam,s hard shell are examples of the resources are marginal-just at the structural adaptations. The trout's ability threshold-the organism will survive. If to extract oxygen from water, the skunk,s any of the resources falls below the level ability to produce and spray disgusting needed by the organism, it will die. In this defensive chemicals, the beers ability to regard life is tenuous, dependent upon transform nectar into honey, and the uninterrupted access to the requirements ability to reason are examples of for life. functional adaptations. The squirrel's

The resources for life originate in an propensity for storing nuts, the black

organism's environment. The relationship bear's long winter hbernation, the

bemeen an organism and its environment herring's habit of schooling, the crayfish's

is, therefore, critically important. active territorial defense, and the arctic

Environments are notoriously dynamic. tern's long annual migration are examples

When an environment changes, organisms of behavioral adaptations.

that interact with it are influenced. A The particular combination of adaptations change in the environment might improve expressed by an individual defines the the for a given organism to lifestyle that that organism will lead and survive. On the other hand, a change the environment in which it can survive. might decrease its survival potential. Furthermore, a change in the environment might enhance one organism's ability to survive and reproduce more offspring while it decreases the chances of another organism.

VARIATION WITHIN A SPECIES

Organisms of the same kind are all

members of the same species. All members of a species have similar adaptations and, therefore, the ability to live in the same environment. The members of a species that are living together and interacting constitute a

population. All members of a population do not, however, have identical traits. Within a population there is variation.

Variation is the amount of difference in physiological and/or behavioral attributes exhibited by the members of a population. Variation can show up in an organism's structures. Some giraffes, for example, have longer necks than others. There is variation in neck length. Some trout have larger, darker spots than others. There is variation in pattern. Some sulfur butterflies are brighter yellow than others. There is variation in color. And so it goes. Look at individuals in the same age class in the species Homo sapiens and you will see a great deal of variation in size, strength, eye color, hair color, amount of hair, number of teeth, sensitivity to cold, and so on.

BIOLOGICAL IMPLICATIONS OF VARIATION

When the environment provides abundant resources, all members of a population share in the bounty and survive. Optimal

conditions, however, are the exception rather than the rule in nature. Often some factor in the environment is in limited supply or pushing the limits of tolerance of the organisms. This is where variation is essential to the survival of the species.

The individuals that have structures or behaviors that allow them to break slightly harder seeds, run a little faster, produce broader leaves to capture more sunshine, store a little more water, and so forth, will have a survival advantage over other members of the population when the environment changes. As a result of natural variation in a population, the population may survive failure of a primary food source, invasion by a fleet predator, reduction in solar radiation, or drought. It is important to note that difierent members of the population will have the advantage, depending on what environmental factor imposes pressure on the population. The result is that some members will survive to reproduce,

Variation extends to behavior as well. ensuring the survival of the species and Some silk moths spin denser cocoons than the continuation of the population. others. There is variation in construction.

Some red-winged blackbirds defend larger territories than others. There is variation THE ORIGIN OF VARIATION

in range management. Some sunflowers One of the big ideas in biology is the bloom a few days earlier than others. origin of variation in organisms. The first There is variation in timing. Some people fully elaborated explanation of the origin - sleep later, talk louder, eat more, play more and role of adaptations in organisms was sports, or read more than others. There is by French naturalist Jean-Baptiste-Pierre- a lot of variation in human behavior. Antoine de Monet de Lamarck (1744-1829)

in his book Zoological Philosophy (1809).

His arguments were logical, but were shown later to be wrong. Even so, it is important to explore his reasoning, as i t

might also be the reasoning of some students.

In his work Lamarck proposed the incorrect idea that individual organisms change in response to pressures from the environment in order to advance their

chances of survival. For example, Lamarck thought that the turtle hardens its shell in response to repeated assault by predators, the giraffe's neck Iengthens as it reaches for ever-hgher foliage in the trees, the red- winged blackbird enhances the amount of red on its wings to better attract a mate, the poppy blooms earlier in the spring to take advantage of residual soil moisture, and a philodendron grows larger leaves to take advantage of the limited light filtering down to the forest floor. Because these modifications enhanced the survival of the individual, and therefore its probability of reproduction, Lamarck proposed that the acquired characteristics were passed on to the offspring.

The Lamarckian theory of evolution that grew out of this explanation of the origin of adaptations was accepted for a time, but by the middle of the 19th century it had been refuted. Changes in structure and behavior that occur during an organism's life cannot be passed to its offspring. It just doesn't work that way. But students often think this way, so it is important to understand why this is incorrect.

Adonis. Later, he marries and settles

down, producing offspring in due course. Will his male progeny be husky and strong, reproduced in the image of their

transformed dad? Not likely. They will have his tendency to be scrawny and victimized, just like Dad was at birth. But

they will doubtless have mherited, like hm, the adaptation for superior muscle development in response to a rigorous bodybuilding regimen.

In 1859, after more than 20 years of fieldwork and rumination on the subjects of adaptation, variation, and speciation, Charles Darwin published his conclusions called O n the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races i n the Struggle for Lijie, usually referred to as T h e Origin of Species. In it Darwin described the origin of variation as a random occurrence that takes place during the process of reproduction. In this way it is possible for offspring to vary somewhat (or significantly) from their parents, as well as from their siblings. Furthermore, the variation may or m a y not contribute to the improved survival of the individual sporting the variation.

The adaptive value of a population's variation manifests itself when the environment imposes pressure on the population. If the climate turns hot, rabbits with thinner fur will dissipate heat better than rabbits with thicker fur. Thin fur in this case is a trait that gives an advantage. On the flip side, if the climate

Here's an example. The 95-lb. weakling turns cold, thick fur is an advantageous

grows weary of having sand kicked in his trait, and thin fur is a liability. If the

face every time he goes to the beach. He climate remains unchanged, fur thickness

enrolls in a bodybuilding program and offers neither advantage nor

bulks up to be a magnificent 210-pound disadvantage-it is just a variation.

If the climate does make a permanent shift Students will be challenged by t h s idea

to cold, those rabbits that randomly that organisms don't decide how to

happened to have thicker fur will survive modify their structures and behaviors to

better, and, in the long run, they will their advantage. They will be tempted to

reproduce more. As a result of the adopt the logic that seduced Lamarck. It is differential reproduction, the population doubly difficult because the most will in time have thicker fur. The thicker important adaptive characteristic of

fur is an adaptation. The important thing humans is the evolution of the brain as a

to remember is that no rabbit decided to flexible, logical, problem-solving organ.

have thicker or thinner fur-fur variation Because brain power is such a powerful already existed in the population, it just adaptation, humans have been extremely

happened. The environment imposed successful organisms on Earth. One

pressure on the rabbits, selecting those manifestation of brain power is that Homo with thicker fur to survive and reproduce. sapiens can consciously modify themselves

The rock ptarmigan is a small member of the grouse family adapted to live in arctic regions year-round. It feeds and nests on the ground in small family groups. During the fall it molts its brown summer plumage and grows a fresh set of white feathers and a dense downy underlayer for winter. The color and insulation permit the small bird to survive in the bitter arctic winter environment.

and their environment, effectively changing their defensive strategies, modifying their body covering, moving faster, communicating effectively, and securing food in many different ways. Humans are adaptable, but this must not be misunderstood as adapted. These changes and behaviors do not get passed down to the next generation, only the brain power to think them up gets passed on.

In the spring the ptarmigan again molts, restoring its lightweight, brown summer ADAPTATIONS FOR SURVIVAL

plumage. This elaborate process of feather replacement could be construed as a conscious, plamed behavior on the part of the ptarmigan, but it is not. Just like the giraffe's long neck, the rattlesnake's rattles, and the redwood tree's fire-resistant bark, the ptarmigan's dual-colored, variably insulated coat is the result of random change over time that resulted in an organism adapted to live in the arctic.

Other variations may have shown up in the ptarmigan's features along its evolutionary path, but those that prevented survival in the arctic environment disappeared from the

One of the popular terms extracted from Darwin's Origin of Species is "survival of the fittest." By this Darwin meant that the organism with adaptations that allow it to acquire resources and reproduce more effectively than another is the one that will survive. The wordfittest is perhaps misleading. This is another example of common usage versus scientific usage of a word. In common usage, because of the emphasis on physical prowess and athletic conditioning, most students will think that the phrase means the most robust individuals will succeed. However, in the scientific sense of the phrase, it means the

ones best adapted to respond to the shaped flowers. The flowers, however, pressures of the environment will survive. can range from pale pink to deep royal "Survival of .the fittest" thus means the purple. Colored flowers is a feature of organisms that fit best with their larkspur; the particular color of flower is a surroundings will thrive and reproduce. trait displayed by an individual plant, and

FEATURES AND TRAITS may vary from plant to plant.

Organisms have distinctive features that make them recognizable. Perch have scales, fins, eyes, and a mouth. Grasses have blade leaves, fibrous roots, tiny flowers, and lots of seeds. Snakes have scales, color patterns, eyes, and mouths. Pine trees have massive stems, large roots, needle leaves, and seeds in cones. Ducks have feathers, beaks, legs, webbed feet, and eyes. Cats have fur, eyes, teeth, color, and tails. Features are structures of organisms.

There is tremendous variation in features from species to species but all individuals of the same species have the same features. There can, however, be variation in how the features look within a species- variation from individual to individual. .

The appearance of a feature within a species is called a trait. A trait is the particular manner in which an organism exhibits a feature, that is, how it looks.

Let's look at some examples. Black bears all have the same features: four legs, short tail, small ears, two eyes, long, coarse fur, and a brown nose, among others. The color of the fur can vary from jet black to honey yellow. In this case, fur color is the feature, and black fur is the trait for one individual.

A classic scientific investigation looked at the feature of wing color in the peppered moth of England. This little moth can

vary from almost white with dark dots on the wings to completely black. In its typical form it is Iight-colored. Light- colored wings was the predominant trait before the Industrial Revolution.

When the Industrial Revolution filled the air with pollutants, the fragile light- colored epiphytic lichens on tree trunks and branches died, leaving the dark trunks exposed. The moths with the white color trait were easy for predators to see on the tree trunks, and they were eaten. Moths with the dark color trait were less often seen by predators, so they survived to reproduce. Moths with dark wings tended to have offspring with the dark- wing trait.

Humans have colored hair and colored irises. Hair color and eye color are features of humans. There is variation in hair color from jet black to nearly white and variation in eye color from pale blue and green to dark brown. Hair and eye color are features of humans; the particular hair color and eye color of an individual are traits of that person.

Larkspur is a plant that grows in moist The ideas of feature and trait are discussed

meadows. The plants share common in greater detail in Investigation 9, when

features that make them identifiable to we introduce the fundamental mechanism

plant fanciers: small green leaves, tall that determines traits, the gene.

central stems, and clusters of distinctively

WHY DO I HAVE TO LEARN THIS? "So, people are different. I know that Many students think that adaptations, like

already. Some people are tall and some warm fur, sharp talons, wings, venom, - have freckles. It doesn't really matter- webs, fins, and fragrance, are the clever

we're all people-it's just that we are devices that organisms developed to help individuals. Individuals are supposed to them survive. They tend to attribute be different from one another. Otherwise conscious decision and deliberate action to the world would be too boring." the processes that produced the features

and traits, for example, the giraffe grew its It's true, we are all people, just like goldfish are all goldfish, spotted owls are neck to reach high branches; the frog grew

all spotted owls, and orcas are all orcas. webs between its toes to swim better; the

Even so, there is variation in all mosquito developed a proboscis to suck

populations, and the variation is doubtless blood; the monkey developed a prehensile

perceived and factored into the way tail to keep it from falling out of the trees.

members of a population interact. T h s is The idea that these and millions of other the level of awareness that middle adaptations emerged by chance or as schoolers will bring to the study of accidents is not intuitive to students. The variation, and it is a good place to start. idea that the adaptations we see today are

An important notion for students to start thinking about is that variation in traits may be present but undetected in a population. Traits that allow an organism to respond to changes in the environment can be the fulcrum on which the balance between life and death pivots. Such traits may reveal themselves as important for

the "happy accidents," the ones that worked to the organism's advantage and helped it survive, is equally difficult. The

countless unhappy accidents that did not help an organism survive are the features we can read about in the fossil record or dream about, but they are not expressed by organisms on the planet today.

survival when conditions change. An Students' understanding of ecology and animal that is just a little more heat natural selection hinges on the tolerant or a plant that sets seed just a bit fundamental concept of adaptation. earlier than others in its population could Carefully monitor their progress with this be the one that survives to reproduce if the difficult idea. Adaptations determine the environment presents a particular set of relationships organisms have with their challenges. In another instance, however, environment. An organism's relationship -

it might just as easily be the individual with its environment is a matter of life and that is just a little more cold tolerant or death. And remember, an organism's sets seed a bit later that survives. environment is everything surrounding it, Variation within a species is one way to physical objects and conditions as well as

- ~

ensure that some members of a population all the organisms of its own kind and every survive to continue the population line. other kind.

;;l

Exploring Human Traits Summary Genetics can be a confusing concept for many students to understand. In order for the class to begin to understand genetics, they will first study variation in human traits. Students will start learning about the study of heredity by surveying their own features. They will learn that they possess single gene traits with simple dominance inheritance patterns such as earlobe attachment, tongue rolling, and bent little finger. Students will work in groups, and after surveying their partners, the data of the class will be collected and patterns of inheritance will be discussed. Objectives

• Students will describe human traits. • Students will distinguish which trait they possess for chosen features. • Students will organize data, calculate percentages, and create graphs. • Students will identify patterns and discuss conclusions for those observed

patterns. Materials Rulers (1 for each group of 2) Grid for Vocabulary Bingo, or have each student take out a piece of paper and make their own grid (5 squares down x 5 squares across). Vocabulary Review Sheet-Can be used as transparency or a handout. Internet access if added background material is needed- Teacher Prep Activity

• Xerox “Genetic Variation” readings, grids for Vocabulary Bingo Vocabulary Review Worksheet and Exploring Human Traits Record Sheets for students.

• Xerox a single copy of the Human Traits that can be used for teacher. Background With the invention of better microscopes in the late nineteenth century, biologists were able to discover the basic facts of cell division and sexual reproduction. With these new discoveries, scientists began to focus genetics research to understanding how hereditary traits are passed on from parents to their children. Genetics is the branch of science that deals with inheritance of biological characteristics. Within a population of organisms there will be variation among the individuals in the population and this is the reason for population change and differences. Within a population of sexually reproducing organisms, every individual within that population will be unique and vary in their traits, behaviors and environmental needs. Genes are the basic units of heredity and they are what make each individual’s characteristics, traits and behaviors different. Genes are found along the DNA strand. DNA (deoxyribonucleic acid) is made up of nucleic acids, which are large molecules that hold the story of life. DNA is the specific nucleic acid that deals with determining the genetic code of each individual. Typically, DNA molecules are quite long, approximately 5 cm long and in order to fit within the nucleus of the cell, they are coiled and tightly wound into a structure called a chromosome. branch of science that deals with inheritance of biological characteristics.

Genetic Variation Concepts Within a population of organisms, individuals will exhibit variation or differences among their features. Genes are the basic units of heredity and they are what make each individual’s characteristics, traits and behaviors different. Standards addressed 7.1.3, 7.5.2, 7.5.3 Duration 60 (+) minutes Vocabulary Genetics Variation Genes DNA Nucleic Acids Chromosome Alleles Traits Dominant Recessive Homozygous Heterozygous Source Material Adapted from FOSS

PRISM UHH GK-12

Organisms have different number of chromosomes, some organisms has as few as two, while some have up to a thousand. Humans have 23 different chromosomes and each of those has an identical partner chromosome. The paired chromosomes that are similar are considered to be homologues and each chromosome has the same genes. These two genes interact with each other to produce the characteristic they are assigned to and the two copies of the genes are called alleles. When the two alleles are considered together, they make up a single gene. When a gene is composed of two identical alleles it is considered homozygous. When the gene is composed of two different alleles, the gene is heterozygous. Gregor Mendel, an European monk, became known as the “father of modern genetics” for his study of inheritance of traits in pea plants. Through selective cross-breeding of different traits (tall, short, purple flower, white flower, smooth seed) of pea plants Mendel discovered the basic principles of heredity. Over many generations of breeding pea plants, Mendel discovered that certain traits show up in offspring without any blending of parent characteristics. For example, when pollen from tall plants was used to pollinate the flowers of short plants, all the offspring were tall. There was no mixing of tall and short plants. In the previous example, the trait of “tall” which exclusively appeared in the first generation (F1) and reappeared in the second generation (F2) was identified as the dominant trait. The second generation also revealed the “short” trait that was absent in the F1 generation. This trait that was absent in the F1 generation but present in the F2 generation was identified as the recessive trait. Unfortunately, Mendel did not know about DNA, chromosomes, or genes and was unable to understand the biological and physical processes that allowed inheritance to occur and the importance of his work was not recognized until many years later. Procedure 1). First have students read background information about Genetic Variation. This can either be assigned as homework, or this can be done as a lesson during class prior to this activity. If the reading is to be assigned as homework, be sure to take a period to go over the information since some of the vocabulary can be complex. 2). Play a round (or two) of Vocabulary Bingo and then review genetics vocabulary sheet as a class. 3). Divide students into groups of two and give each group a ruler (ruler will only be used if the traits that you assign to survey need to be measured). First ask the students if they think there are differences among humans and have them give examples of possible differences. Ask them if there were going to describe a person, for example, if they needed their parents to go pick up a friend that their parents had never met, how would they describe their friend to their parents. Hopefully they say things like “my friend has brown hair, they are tall, they have brown eyes, etc.”. Explain to them that they just described traits about a person. They will now survey their own traits. 4). On the list of traits provided, choose up to five traits and be sure to introduce the traits and go over them with the students. Each feature only has two traits, so each student should have one or the other trait. Let students know that their assignment is to discover which trait they have for each of the assigned features. For example, if the tongue trait is chosen, the student will either be able to curl their tongue or not. 5). Give the students about 10 minutes to observe each other and determine which traits they possess. Have the students record their traits on a piece of paper. They should write which feature they have and the trait, either the dominant or recessive trait. Dominant traits will be symbolized by 2 capital letters (TT) and recessive traits will be symbolized by 2 lower-cased letters (tt). This actually defines the genotype of the trait. 6). Poll the class by having the students come to the board and tally their results. On the board, have each trait written out and next to each trait, each student can make a tick or a check next to the trait. For example: Then determine the percentage of students in the class that have the certain trait. The class can also be polled using a transparency, having the students raise their hands and report to the teacher which traits they have.

Tongue rolling: TT ___________ “5 students” tt ___________ “2 students”

7). Talk about the results. Is there variation among the students? Which traits occurred the most? Are the traits linked? If you can roll your tongue, is your little finger always bent? Summarize the results, determining that there is variation among the students in the classroom. 8). Have the students create a bar graph of their results on the back of their Exploring Human Traits Record Sheet. Teacher Resource Extensions: FOSS Genetic Vocabulary Review Worksheet (included) When introducing the material, students can visit the web site http://www.dnaftb.org/dnaftb/1/concept/index.html (DNA from the beginning) and choose chapters to explain some of these complex concepts. The animation tab for each chapter is a beneficial way to have students engaged in the material. Chapters 1-5 can be used for the topics of inheritance. Resources file:///Users/universityofhawaiihilonsfprismgk-12/Desktop/GK-12%20/Human%20Traits.webarchive http://www.dnaftb.org/dnaftb/1/concept/index.html Foss-Populations and Ecosystems

Human Traits

1. Shape of face (probably polygenic)

Oval dominant, square recessive

2. Cleft in chin No cleft dominant, cleft recessive

3. Hairline Widow peak dominant, straight hairline recessive

4. Eyebrow size Broad dominant, slender recessive

5. Eyebrow shape Separated dominant, joined recessive

6. Eyelash length Long dominant, short recessive

7. Dimples Dimples dominant, no dimples recessive

8. Earlobes Free lobe dominant, attached recessive

9. Eye shape Almond dominant, round recessive

10. Freckles Freckles dominant, no freckles recessive

11. Tongue rolling Roller dominant, nonroller recessive

12. Tongue folding Inability dominant, ability recessive

13. Finger mid-digital hair Hair dominant, no hair recessive

14. Hitch-hiker's thumb Straight thumb dominant, hitch-hiker thumb recessive

15. Bent little finger Bent dominant, straight recessive

16. Interlaced fingers Left thumb over right dominant, right over left recessive

17. Hair on back of hand Hair dominant, no hair recessive

Ll

Use this tally sheet to keep track of the different traits that your classmates have. Under “Trait” write the different traits that your class has decided to survey, such as Dimples or Tongue Rolling. Under “Dominant” or “Recessive”, record the tally marks or check marks of your classmates. Then determine the percentage of students that are either dominant or recessive for the trait.

TRAIT DOMINANT RECESSIVE % (# ÷ Class total) Example: Dimples √√√√√√√√ √√√√ 8 ÷ 4 = 2% Dominant ____________________________: _____________ _____________ _______(D) ______(r)

= _______%

____________________________: _____________ _____________ _______(D) ______(r)

= ________%

____________________________: _____________ ______________ _______(D) ______(r) =________% ____________________________: ______________ ______________ _______(D) _______(r) =________%

____________________________: _______________ ______________ _______(D) _______(r) =________%

Exploring Human Traits Record Sheet

Name:________________________

Name -

Period - Date

' 4 GENETICS VOCABULARY *****.***e.*e*.e *.*.*****....*....**..*. . . *...*.***.*****.

The offspring of organisms often grow up to look like one or b )th of their parents. This is because offspring inherit info mation from their parents that directs their development.

The inherited information 1 - 1 rated in the of every cell in the organism. The

information is coded in the 'luge molecule. The huge molecules are coiled into

compact hot dog-shaped s. ictures called are always

present in almost identical lirs. Locations on chromosomes that affect features of

organisms are called . A gene is composed )f

An organism's unique combination of genes is its . The traits produced

by an organism's genes is its . Alleles that ha more influence in

determining traits are alleles. Alleles that have 1: , influence in determining

traits are alleles.

1

FOSS Populations and Ecosyster Zourse 0 The Regents of the University c alifornia Can be duplicated for classroom c . vorkshop use. 55

Investigation 9: Genetic Variation Student Sheet

Answer Key for Genetics Vocabulary Worksheet

1). Nucleus

2). DNA (nucleic acid)

3). Chromosomes

4). Chromosomes

5). Genes

6). Bases (sequence of bases or nucleotides)

7). Genotype

8). Phenotype

9). Dominant

10). Recessive

Answers for picture of cell

First Block: Chromosome

Second Block: Gene

Third Block: Nucleus

Fourth Block: Allele

Genetic Variation Concepts Genes are passed on from one generation to the next and this is the concept of heredity. Genes code for what an organism will look like and are carried by chromosomes. Chromosomes, which occur in nearly identical pairs in the nucleus of every cell, are responsible for passing on hereditary information. Depending on which alleles an organism has will determine how the organism will look and behave. Standards addressed 7.5.2, 7.5.3, 7.5.6 Duration 1-2 60 minute class periods Vocabulary Happy-face Spider Homologous Phenotype Genotype Punnet square Probability Homozygous Heterozygous Morphs Source Material PRISM

Happy-Face Spider Propagation Summary Students will act as captive breeders in order to simulate how genes are passed on from one generation to the next. They will also observe how small differences accumulate over time to produce descendants that look very different from their ancestors. Students will use the Happy-face spiders (Theridion grallator), a spider that is endemic to the Hawaiian Islands and exhibits genetic variation. Spiders on the island of Maui follow basic Mendelian genetic patterns, so they will be useful organisms for this lesson. This simulation will help students determine how genetic information is transferred during breeding, and what the resulting phenotype (how they look) will be. They will decide which traits are most important to breed in order for better survival for the spiders. Students will also be introduced to Punnet squares, which will be used to predict the proportion of offspring with each trait. Objectives

• Students will learn about a species that is endemic to Hawaii • Students will simulate how genes are passed from one generation to the

next. • Students will act as captive breeders and choose which traits will help the

survival of the spiders. • Students will use Punnet squares to predict the proportion or frequency of

which genes will be passed on. Materials Pictures of Happy-face spiders that show variation in color. Pink and Blue Card Stock-each group of 2 students should have a total of 12 pink cards and 12 blue cards. (Size of playing cards). Need one set for use in explaining concept to students. Clear transparency to go over Punnet squares Paper for student Punnet squares. Hand-out of Happy-face Spider for students to color using their color choice. Background Happy-face spiders are found in the rainforests of the Big Island, Oahu, Maui and Molokai. They are usually found on the underside of leaves. Happy-face spiders have a pattern on their body that resembles a smiley face. Every spider has a unique pattern and the body color differs from island to island. Some of the spiders lack the pattern of the smiley face alltogether. These different morphs (forms) are caused by the different gene versions carried by the spiders. The combination of alleles on the homologous chromosomes (similar, paired chromosomes) which determine a specific trait or characteristic is the organism’s genotype. The way the information is expressed and how the spider looks is considered its phenotype. Genotypes and phenotypes of an organism can be determined with the use of a Punnet square which estimate the probability (likelihood) of genetic combinations being passed on to potential offspring. A Punnet square is created by crossing either homozygous (two identical alleles) alleles, heterozygous alleles (two different alleles) or a combination of both on a grid. Researchers believe that the variation of color and pattern in Happy-face Spiders is a possible type of camouflage against birds, their only significant natural predator.

PRISM UHH GK-12

In order for these spiders to escape predators they must be able to blend into their natural environment. If the student is to be the captive breeder they must decide what would be the best color for the spider to survive in the wild. Teacher Prep for Activity

• Review background reading for Genetic Variation • Xerox Happy-face Spider Drawing page. • Cut out cards for the students: a group of two students will have one set of 12 blue cards and one set of

12 pink cards. Be sure to make a set to use as an example when explaining the activity to the students. Except for the set to be used by the teacher, the other sets of cards should remain blank since the students will be writing in the color traits that they will be using. These cards could be laminated and used year after year, if dry erase markers that could be cleaned off were used.

• Have a clear transparency handy to go over the Punnet squares after they have finished the “card game”. Procedure 1). Split students into groups of two and pass out drawing sheet. One student will act as the MOTHER passing on traits to its offspring and they will receive 12 blank PINK cards. The other student will act as the FATHER passing on traits to its offspring and they will receive 12 blank BLUE cards. 2). Before the students start working on the cards, have them draw a Punnet square (more information about Punnet squares can be found on pg. 257 in the FOSS readings at the back of the lessons) to determine what the probability of allele combinations will be (this can be done on the back of the drawing page). The students will have to choose if the dominant parent will be either heterozygous (Ww) or homozygous (WW or ww). They should work together on creating the Punnet square. 3). Ask the students to determine which color they would like to represent. Remember: this color should be beneficial for their survival in the wild. If a student chooses fluorescent pink, they will have to explain how this color would allow the spider to be camouflaged in the rainforest. The mother and the father should be 2 different colors. For example: Mom=White, Dad=Yellow. 4). Next, ask the students to choose which color is going to be dominant and which is going to be recessive and assign the correct genotype to the respective trait. Remember: the letter designated must be the same for each color but must be represented by either a capital letter or lower cased letter. For example, if mom is considered to be dominant for White, then her genotype would be WW or Ww (students can choose, WW x ww will only have Ww offspring which will all be the dominant color, white in this case. If more variation is wanted in offspring, have the dominant parent be Ww, since Ww x ww will have 50% white and 50% yellow) and eventhough dad is yellow, his recessive genotype would be ww. 5). Ask the students to take a card and write one allele type per card. For example, for mom, each pink card should have a W written on half (6) the cards and the other half (6) will have a lower-cased w written on them, if you make mom heterozygous. If mom is homozygous then all her cards will have W on each one. For the blue cards, for dad, each card should have a lower-cased w written on it, since the gene is recessive he will only be passing the recessive gene on. 6). Now have the student with the pink cards shuffle their cards and the student with the blue cards shuffle their cards as well. Then have the students lay all the pink cards out next to each other and below that row of cards, lay out all the blue cards. Be sure the cards are lined up above and below each other to show how the different genes line up. 7). Once the cards are laid out, have the students look at the frequency of the combinations of traits. Ask the students to compare the probabilities of the allele combinations from their Punnet squares (on the back of their drawing page) to the frequencies created from the cards they made.

Assessments Journal writing and coloring picture of spider to accompany writing or defense of color choice. Class presentation on spider color choice Resources http://evolution.berkeley.edu/evolibrary/article/_0/happyface_02 Google images-http://images.google.com/ Foss-Populations and Ecosystems

UHH PRISM Drawing by: Bobby Hsu Bobby Hsu

Name: ____________________________

Color the body of the Happy-Face Spider the color that was chosen to breed the spider for survival in the wild. Use the extra space behind the spider to draw the habitat where this spider can be found.

Look under a leaf and find a smiling surprise. But look out, because I like to catch my prey in a silken trap.

WHO AM I?

Color the numbered spaces to find me.

1 = red 2 = black 3 =-.-.a f l I n R. S -hL .+ C b o ~ 0 3

Unscramble the letters to find out. 1 .

P Y P A H E F A C D E P I R S

Coloring and Activity Book

.- ...... - -b-..--.. 3565 Harding Avenue Honolulu, Hawai'i 96816

http://nature.berkeley.edu/~gillespi/re

search.htm

http://nature.berkeley.edu/~gillespi/research.htm

http://nature.berkeley.edu/~gillespi/research.htm

http://nature.berkeley.edu/~gillespi/research.ht

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http://nature.berkeley.edu/~gillespi/research.htm

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Alle mt or recessive. Dominant alleles exhibit the 2 present on one chromosome; recrsslve alleles exhibit their effect only when they are on both chromosomes.

An organism's particular combination of paired alleles is its genotype; the i duced by those alleles result in the organism's phenotype.

A gene composed of two identical alleles (e.g. both dominant or both recessive) is homozygous; a gene composed of two different alleles (i.e. one dominant and one recessive) is heterozygous.

CONDUCTING INVESTIGATIONS Observe vari luman tr( arkey traits.

Use a simula 2termine fer of genetic information during breeding and the traits that result.

Use Punnett squares to predict the proportion of offspring that will have certain traits.

BUILDING EXPLANATIONS Explain how organisms Inherit features and traits from their parents.

Describe how dominant and recessive alleles interact to produce traits in a population.

- ;-, , - 1 SCIENTIFIC AND HISTORICAL BACKGROUND I

In their ecoscenario studies, students were introduced to two dozen or so key organisms that interact in a particular ecosystem. That's quite a few organisms to keep track of for middle schoolers, but in fact, the handful of species presented for study represents only a tiny fraction of the actual number of species living and interacting in the most diverse and robust

organisms in an ecosystem is one of the monster questions in biology. Presumably life started on Earth as one kind (or possibly several) and over the last 3.5 billion years diverged into hundreds of millions of different kinds, a small Fraction of which are living on the planet at this time. What process could have produced so many kinds of organisms?

, ecosystems. . i Most biologists concur that the theory of

Diversity raises questions. How can so natural selection provides the answer. The I

many different populations live in the theory stands on several tenets.

same ecosystem? And where did the First, there is variation in a population of different species come from in the first organisms. The variation can be the result place? of mutations and recombinations in the

; In Investigation 8 students were introduced to important concepts that get at the first question. The simple answer is that all organisms living in an ecosystem have adaptations that let them get the resources they need to live and reproduce. Close analysis reveals that every species has a unique suite of adaptations. This ensures that when resources are limited, every organism will use at least slightly different resources, in a slightly different way, at a slightly different time, in a slightly different place. In this way organisms keep out of each other's way and avoid excessive competition for valuable resources. In a sense an organism is defined by its adaptations; similarly its role in the ecosystem is defined by its adaptations. Organisms that are not adapted to live in a particular ecosystem are not found there.

genetic code, but these concepts will not be pursued in this course. Variation in a population may be the result of immigration and emigration (gene flow) or the random change in the frequencies of alleles (genetic drift). We will accept as a fact of life that there is variation in the many features of individual organisms, and they stem from natural processes. These variations are traits.

Second, environments are dynamic, continually presenting new and different challenges for the organisms living in them. The environmental change could be the introduction of a new organism better adapted to compete for resources, a change in the climate, a disaster of some kind, or any number of subtler changes. An organism that was adapted before the change in the environment may not be adapted to cope after the change.

Why there are so many different kinds of Ecologists call this changed condition a

selective pressure. The change in a very real way selects the organisms that will succeed and those that will fail. There is, of course, no conscious decision to select this organism and eliminate that one.

If the selective pressure is radical, a whole population may succumb. If the pressure is slight or incremental, however, the pressure may be felt by only some members of a population. That is to say, some traits, such as thin fur, pale skin, or short legs, might preclude an organism from acquiring resources or reproducing, so those traits will be selected against in the population. Other members of the

of time, from decades to scores of millennia, the two populations may have diverged to such an extent that, even if they were reunited, they would continue to conduct their separate lives, unable to mate and reproduce.

That's an oversimplified picture of the origin of species, but in practice the science of identifying the precise point in this process when a new species has arrived is daunting, and even a precise definition of what constitutes a species is illusive. We will not enter these deep waters in this course.

- - population might continue to survive and reproduce, perpetuating their traits. In MECHANISMS FOR POPULATION

this way the appearance and/ or behavior CHANGE

of a population as a whole can change, The key to population change is variation :. sometimes in a relatively short time. among the individuals in the population. - ,

The third factor contributing to natural selection and the evolution of new species is isolation. As long as the members of a population interact and breed, they will not normally generate a new species. The population may change over time, but will not become a new species. If one portion of a population is separated from the other, either physically (isolated by geography) or behaviorally (exploiting different food sources), creating two populations, new species may evolve.

When a portion of a population emigrates or is transported to an island or new continent, the selective pressures in the two environments-the originating environment and the new environment- may favor different traits. After a period

In a population of sexually reproducing organisms, each individual is unique and therefore has ever-so-slightly different needs, behaviors, tolerances, and responses to stimuli from the environment. When the environment changes, the makeup of the population changes in response.

What makes each individual unique? Genes. The genes that direct the assembly of molecules into organisms are different for every individual.

This discussion applies to organisms that reproduce sexually. Organisms that reproduce by simple division, producing two genetic clone daughters, follow a slightly different path to achieve

1 population change.

The simple version of genetic transfer of information goes like this. The story of life is recorded in huge molecules called nucleic acids. The specific nucleic acid that handles the genetic code is DNA (deoxyribonucleic acid). The long filaments of DNA are made of millions of sugar - and phosphate units bonded together, with organic bases sticking out to the side. Picture a comb. The sugar /

backbone sports

like tines.

9 The bases sticking out are key

to the structure of DNA. The four bases are adenine, thymine, guanine, and cytosine, usually represented by the symbols A, T, G, and C. The bases can bond with one another, but only in specific bonding pairs. A and T can bond with one another, and C and G can bond, but A cannot bond with C or G, and so on. Base pairing is specific, and there are no exceptions.

The bases on two sugar / phosphate strands bond and form a double DNA strand called a double helix. The result is a long ladder with the bonded bases forming the rungs.

A typical DNA molecule might be 5 cm Organisms have different numbers of long. To fit in the nucleus of a cell, the chromosomes-as few as two to well over huge molecule is coiled (wound into a a thousand. Most vertebrates fall into the helix) and recoiled into a compact 20- to 80-chromosome range, and humans structure called a chromosome. have 46. Toads have 22 chromosomes, and ,

chickens have 78. Plants and animals that - reproduce sexually generally have an even number of chromosomes because a set of chromosomes is made of nearly identical pairs. In humans, for instance, there are 23

The order in which the paired bases are aligned along the length of the DNA molecule is all important in decoding the message to make a new organism. Just like the 26-letter alphabet can be used to make untold numbers of words, depending on their sequence, the four-letter genetic code can make untold millions of "words,"

Organisms that have pairs of chromosomes are called diploid. Some organisms have

distinctly different chromosomes, and each of those has an almost identical partner. The two similar chromoson~es are called homologues.

Every cell in every plant and animal on Earth has a complete set of chromosomes that define the organism. 7'he chromosomes reside in the cell's nucleus.

depending on the number and sequence of the bases. The plan for making a

mosquito, tree frog, banana plant, gila monster, begonia, blue whale, or any other organism is encoded in the sequence of the same four bases distributed along the

incredibly long double helix molecule.

multiple copies of s imi larchr~~oso*es and are polyploid. We will deal only with diploid organisms in this

and in this course.

Every time a cell divides to produce two daughter cells, the complete set of chromosomes is duplicatecl. Each new cell is provided with a full complement of DNA-the complete set of blueprints and operating instructions for irssembling and managing one particular kind of organism.

, : , ._/ . . . . . . . . . . . . ,..l ,,: , . . , , . , 8 . . . ........ . . . . . . . . . . . .

i _ " .:;, :, .?.' . . ., . ..,:,!: DETERMINING TRAITS When alleles are identical, both forms of

;> ,);,., ,:;...';.~.:.::::,:~;< ;.$;'.; ,. .,: ., , ,; ; :Xb , ' - . . . . . ,, . :,< ;., ,",,., !. . .

, - , , . . . Features, characteristics, traits, and the gene produce the protein that makes, . .;.. ....:... : , , , ; I : ,,,\ l;~,..~~;>:,.:.:.;.'? .,<: .. . . . . . . .. $ .,,,:,.; ~ . . . . . , , ; . , , behaviors are determined by genes. Large attached Or a

.,. , ,. . ~ . . ~. ,,,;. :y . ,.:.,:;>'.:>!>\ . , ' , . ~ . - ......!.. . . . ..: , ri2.. j .., ears on jackrabbits are determined by I widow's peak. 1, .> .:<;. ,:;. ;:c,. .:{%>,

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!'., . ,, ,:,. :. , , genes. The gray color of elephants is If the alleles are not the same, however,

. . . . . . . . , . , . .-. : . . . . . . . . . ..: . . ,. -,. : . ~ . .:& ..- I ...,.' ,> ".] ;I

determined by genes. The spots on and the messages coming from the two . . : , : ...I . . . . . .... .

": rainbow trout, the little friction area that slightly different alleles do not agree, what . . . . . . . . :t l j : j . . ;

. . . . . . . . . . . . . :; .....I , . . . : / . ? .... . I lets crickets crick, and every other feature happens? ln the simplest case (the case

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. . . . . . ! . . of every organism is the product of a ..< .'...,. ' ,: . . . . . . . . . . we introduce to students in this

. . . . . . . _ _ , !:I, . . I . . ' genetic message. . : , . .

. . . . . &:.,,:. : investigation), one of the alleles dominates

. . . . . . . .% ........ .? 1 . . . . . . . . . : ....: , Genes are the units of heredity. Genes are the other and the effect of the dominant

. . . . . . ' , , .. , . ~, ,. , . . . . .- . . . . . , .,! ::. : specific sequences of sugars, phosphates, gene is exhibited in the organism. Such an

, ,. . . . . . . . . . .. > ,!,.',I ,.: ?:. !

. . - and bases along the DNA strand in the allele is called a dominant allele, and the . . . i . . . . < . . .

.'. . . . . . . : . . . _.. . , . , . chromosome. A gene is a sequence of "overruled" allele is the recessive allele.

.. .. ,? :I , .-;.<.;:,.... !

, . + : bases that code for how to assemble a : , , . ! .-.., :.':..

, : . . . . . . . . . , . , . . . . . . . . . . . . , , ,: , , certain protein. The proteins

. . , . ,. . . . - . , . , . : . . . .

THE DISCOVERY OF HEREDITY ... ... .. :... , . , , , . i ' . ;.i . . . manufactured in response to these

. . . . . . . . :,,, . :.c;*, . ..;., : . . , . . . . a . . . . . . . .

. . . . . . . , - :: messages flow into the organisms' cells The pioneer work on heredity was , < . . i . .

..,. , . . . . .

and make things. The things they make undertaken by the brilliant Gregor . . . . . . . . . . . . . ' . are fats, bone, muscle, nerves, and Mendel, son of a Moravian farmer. Young

. . . . everything else that is required to make Mendel demonstrated an aptitude for . . ' . .:. . . .

... ... :, .;,: . . organisms, complete with the characteristic academics, but was in no ~osit ion to . . .

, . . . - . . , ; structures and behaviors that are both . . pursue a university career. In order to

. . . . . , . . typical of their kind and unique. continue his studies Mendel joined an Augustinian monastery. There he

There is another important piece to . .

undertook his detailed inquiry into the . understanding genes. The homologous role of heredity in conveying

chromosomes (the two that are almost characteristics from one generation to the identical) each have the same genes. So it next. would seem that every organism has two genes for every characteristic. This is not entirely true because the two genes interact to produce the characteristic. The two copies of the gene are called alleles. The two alleles considered together constitute a gene.

The homologous chromosomes are usually identical with regard to gene location, but are not identical in sequence of bases. Those differences in DNA structure can result in two forms of a gene or alleles.

Mendel worked extensively with pea plants. He started his long series of experiments by developing a number of strains of pure breeding stock. He did this by raising several generations of self- fertilized plants. The result was separate populations of peas that produced clearly defined and predictable characteristics, such as tall, short, purple flower, white flower, smooth seeds, and wrinkled seeds. Whenever he planted seeds from his purple-flower stock, for example, all the

experiments. He used pollen from tall constructed a functional model for genetic plants to pollinate the flowers on short heredity without knowing the biochemical

. . . - : . I I . '. : . . .. . . plants, and pollen from short plants to and physical processes that carry the , . , , .....: . .. . , '.. ..

; : : . . .. 8

. , .. . . , pollinate the flowers on tall plants. What process forward. , , . . -:. <:.. . .:. . . .

Mendel discovered was that all of the 1 , :, , , 1 . , : ; , : I,:>:, .v4, . ;.<. . . , ,

Tall and short are traits. The parental trait , . . : - . . offspring were tall. This was confusing to 1 , ,.. . ,,?? ~j , , , '.. !::. , .... . . .. :. . I

that appeared exclusively in the F1 , , , ~ , . ;. . i him. c,..+. .,....., j , > , , . . . . , ;

generation and prevailed in the F2 , ,. , .,: .,:.; ,,.: kc .(. .. . . ." . > . . , , . . . , I

, , . .. .. . -.-:?' . . . . Undaunted, Mendel collected the seed generation, Mendel identified as the , , i i i . . . .,.. ~'., _ , : ' . . ,

. . . . from the tall pea plants, which he named dominant trait. The trait that disappeared !:;;.;','' I,. / . . ':..;.'.; . '

, the first filial generation (F1) and planted in the F1 generation but reappeared in the .' ,:,':' :

, . . . . ~. >.

them (filial = son or daughter). Some of F2 generation, he dubbed the recessive . . . . . . . ..

the offspring that grew from the F1 seeds trait. Whenever a seed acquired the 1 ' , . . . . ... . . , , . ,,,, .:.- ;.. . . . . . . < . ,

(F2 generation) were tall, and some were dominant trait from both parents orfrom : : .i ;.. . I : . ~ ..- . . . '

short. Both characteristics were present in just one parent, the dominant trait was the offspring. The characteristic of height expressed in the plant that grew from that had not blended to produce all medium- seed. If the seed acquired the recessive height plants; the characteristics were traitfrom both parents, the recessive trait passed along intact, some exhibiting the was expressed by the plant that grew from tall trait and some the short trait. He that seed. concluded that even though all the F1 seeds came from plants that were tall, when they grew into mature plants, some were tall and some were short. Both traits were present in the offspring, the F2 generation.

Mendel paid close attention to the numbers of each growth form and discovered that there were more tall forms than short forms in the ratio of 3:1, that is, 75% tall and 25% short.

Some 150 years after Mendel puzzled out the probable mechanism for heredity, we understand that dominant and recessive traits are transmitted by genes on chromosomes. When a gene is represented by two dominant alleles, the trait is that of the dominant allele (e.g. purple flowers). Such a condition is called homozygous (same allele) dominant. When a gene is represented by two recessive alleles (homozygous recessive),

At this point Mendel made his the trait is that of the recessive allele (e.g.

revolutionary surmise. He reasoned that white flowers). When a gene is represented by one dominant allele and each offspring must get half its

information about height from each one recessive allele, the organism is heterozygous (different alleles), and the parent. Further, the influence of the

information from the two sources was not trait is that of the dominant allele (e.g.

necessarily equal. Mendel knew nothing purple flowers).

. , . . . . . '

. . i ' . !

Here is an important point. Where purple GENOTYPE AND PHENOTYPE . . . . . . .

flowers are e h b i t e d as a result of a Geneticists refer to the genetic makeup of heterozygous condition-the combination an organism as its genotype. F~~

. . . . . , ..

. . , a ,!.,?. - . : .,. 3. of a dominant and a recessive a l le le the instance, in the example of the two parent .......... 5 ~ . .': . , , . .>:. . . i . ":,; ...,,; . ,.>::,;. I

. . , . . , , . . , . : recessive allele for white flowers is still

..... , ' , , . , .:,. . . . . ,... :. pea plants, the gene for flower color can

. there. < . . . . . . . . . . . . . . . . . . , . z ,._

+. . . . . . . be represented by the letter b (bloom). An

: . \. . . - . , . . ; . ,',;.c j . . I . . . . . . . ' . ? ..;, . . uppercase B represents a dominant allele . T. . . . - . . . . I

, . '. . ' . l i

, , ',

, ' .i NEW COMBINATIONS OF ALLELES

for purple color, and a lowercase b . . . . . , , . '.' .;,

. . . , :.-.,. .,,5 .:;. 1 represents a recessive allele for white . . . . . . . . ,, .;.. :4

, ..:. . . . . . . . , ~ . During the production of sperm and eggs, color. Our two heterozygous parents

. , . . . . . 'I'. ,. , . , : . . . : . . . . . . . a process called meiosis occurs, the

. . , ., . would have the following genotype for

' : . ::I homologous pairs of chromosomes < , , .

. . . . . . . . . . flower color: . . , . .,.

. . . . .. , ,. . separate so that each egg or sperm cell has . . - . . . . . . . . . . . . . . . . . ' only half of the usual number of

. . . . . . . :,

. . . . . . . - i i i I . , .

chromosomes. The two alleles that make a . . ; . . . . . , I I . . . . . . '. : . gene are, therefore, separated. (Meiosis, . . . . . . . . .

. . I ::;. . , . . C ' . . the mechanism for passing just one allele . . . . . . . . . , .

. . Hb 9

. . . . . . .. ,.. \ from the male and one allele from the B b

. . . . . . . . . . . . . . . . . . - , . . . . . . . . . ' . .;. female to the offspring, is not explored in

. a ' . . . . . , ,

this course, but it is one of the most The way the genes are expressed in fur, important factors in hereditary biology.) feather, flesh, and function is an

chromosomes with corresponding alleles. During sexual reproduction, each parent The new sets of form genes that are contributes one allele to the genotype of unique to the offspring. the offspring. The heterozygous flowering

See Page 53 in the Resources for diagrams of mitosis (cell division to form two daughter cells) and meiosis (cell division to form

If two purple-flowered parents are both peas .contribute either a B or a b. If either heterozygous for flower color, it is possible parent (or both) contributes the dominant that the recessive allele for white flowers B allele to the offspring, it will have purple will be passed to the offspring by both flowers. But there is a chance that both parents. Two purple-flowered parents can parents will contribute the recessive b have white-flowered offspring if both allele, in which case the offspring will parents had a recessive gene for white have white flowers. flowers, and each passed it to the offspring. This will happen, on average, in one out of every four offspring.

During fertilization, one set of organism's phenotype. The simplest way chromosomes comes from the father to think of phenotype is how an organism (sperm) and a homologous set comes from looks-its traits. Purple flowers, tall the mother (egg). As the sperm and egg growth form, and wrinkled seeds are cells fuse, the two sets of chromosomes phenotypical traits. An organism's create new homologous pairs of genotype determines its phenotype.

PUNNETT SQUARES The completed Punnett square shows the

*bout years ago ~ ~ ~ ~ ~ ~ l d punnett, a four possible combinations of alleles

Cambridge professor of genetics, contributed by these two parents. These

developed a simple and useful technique are possibilities linked with probability, not absolutes. for predicting the characteristics of

offspring when the dominant and One homozygous dominant recessive traits of the parents are known. Two heterozygous It is known as the Punnett square. The

One homozygous recessive square is a grid, with the alleles of one parent on the top and the alleles of the The heterozygous condition is always

other parent on the left. The flower-color recorded with the dominant allele first,

Punnett square looks like this. followed by the recessive allele.

Female

B b

. . . . . . . . . . -. :. . , 7 , ",' . . . :L .: . . . . . . . . . . . . . . . . . . . ,.

::, . < . .

B b not bB ,,. p :..: ! ' I I, ' ' . '

. . . , . . . . . . , . , : : ' . . . . . . . -~ . . . . . . ,. . , I: , \ : , , , . . ,: ., ;. ).. . ..>,' .. <x .~ !.,t.,.,.' . ' ' . . . . , . .

/. .. ,~_; . . . . . . . . . . . . . < / " ' . , . . . . . . . . . . . . . . . . . . . . .

This Punnett square suggests that there is a 3. ..... :::;.;.. ,.,,:...: :,:,..::,*,;:. .. , . . ' .:. ,. .. , , . .,.. ~ possibility that three out of four offspring : . ' : . . . : . . .

, . ,r , , , .., , , .:. .', ' ., .

. . . . . . . . . . . . . . . will have purple flowers, and one out of .&. . . . . . ~. . : , . , >. . : ,, . . . . .

4 four will have white flowers. T . . . . . . .

, . . . . , , ' . .

Each grid square represents the BLENDED EFFECTS

combination of two alleles. Transcribe It's not always that simple, however. Not

those two alleles into the squares, like this. all alleles are wholly dominant or recessive. Some are partially dominant. In this case homozygous dominant alleles will produce one trait, homozygous recessive alleles will produce a second trait, and heterozygous alleles will produce

Female

B b a third trait, often a blend of the two other traits.

Students are introduced to this when they work with the feature of fur pattern on

Natural Selection Concepts In 1859, Charles Darwin and Aflred Russel Wallace proposed the theory of evolution by natural selection. Their theory was later combined with Mendelian inheritance to explain the connection of genes (units of evolution) and natural selection. This theory has become the principle explanation for species diversity. Standards addressed 7.5.4, 7.5.6 Duration 1 60 minute class periods Source Material w w w.indiana.edu/~ensiweb/lessons/origami.html Vocabulary Natural Selection Phenotype Genotype

Hawaiian Origami Birds

Summary After students have a strong understanding of Adaptations and Genetic Variation, they will be introduced to Natural Selection. They will participate in a natural selection simulation in which they will create and modify “paper airplanes” over several generations to visualize how favorable heritable traits are passed on. These paper airplanes represent wild birds of a population. Objectives

• Students will simulate how genes are passed from one generation to the next.

• Students will understand how traits that are favorable for survival become more common over generations.

• Students will know that both genetic variation and environmental factors causes of evolution and species diversity.

Materials Paper Ruler Tape Straws Scissors Coin Six-sided die Background The Hawaiian Origami Bird (Aves hawaiiensis) lives on the rugged coastline of Hawaii Island. It feeds on Opae'ula (Halocaridina rubra) which are found in anchialine ponds around the island. Due to high development of the coastline on the island, alchialine pools are decreasing and becoming less common. Only birds that can successfully fly the long distances in search of Opae'ula will live long enough to breed successfully. This simulation will allow students to breed several generations of the Hawaiian Origami Bird to see how phenotypes and genotypes are affected over time. Biological evolution, which is the gradual change to a population of species over many generations, is the process responsible for the diversity of species. Natural selection is the process by which favorable traits that are passed on over generations become more common in a population of reproducing organisms. Natural selection is also responsible for how unfavorable traits (not conducive for survival) become less common in the population. This process acts upon the phenotype or the morphological characteristics of an organism. Organisms that have favorable phenotypes that allow them to survive and reproduce in the wild are more likely to survive than organisms that have unfavorable phenotypes. If the phenotype is based on genetics, then the genotype associated with that favorable phenotype will increase in frequency in the next generation and generations to follow. Natural selection also acts upon populations, not individuals alone. The changes to the phenotype and genotype must affect the entire populations of organisms, not just select individuals of the population.

PRISM UHH GK-12 PRISM UHH GK-12

Teacher Prep for Activity • Prior to this lesson, the teacher can cut the paper into different sized strips. Be sure to make many strips of

each size (they will vary from the original size of 3 cm x 20 cm). The width and circumference of the strips will increase or decrease by 1-2 cm after each generation.

• Xerox Origami Data Sheets • The procedure section can be Xeroxed and handed out or the diagrams can be written on the board.

Procedure 1). Split students into groups of two. Each student will prepare an ancestral bird: Cut two strips of paper, each 3 cm x 20 cm. Loop one strip of paper with a 1 cm overlap and tape. Repeat for the other strip. Tape each loop 3 cm from the edge of the straw.

2). Breed offspring. Each Origami Bird lays a clutch of three eggs. Record the dimensions of each chick and hatch the birds using these instructions:

a. The first egg has no mutations. It is a clone of the parent, this measurement will be the same as the ancestral bird. In the interest of time you may substitute the parent when testing this chick.

b. The other two chicks have mutations. For each chick, flip your coin and throw your die then record the results on the table.

i.) The coin flip determines where the mutation occurs: the head end or tail end of the animal. ii). The die throw determines how the mutations affect the wing:

kujkjkjkjkjkjkjkj

After you have determined where the mutation occurs, cut new strips of paper and re-build another bird with the new measurements. You can use the strips from the original bird if able. iii). Lethal mutations: A mutation which results in a wing falling off of the straw, or in which the circumference of .the wing is smaller than the circumference of the straw, etc. is lethal. Fortunately, Aves hawaiiensis birds are known to “double clutch” when an egg is lost. If you should get a lethal mutation, disregard it and breed another chick. 3). Test the birds: Release the birds with a gentle, overhand pitch. It is important to release the birds as uniformly as possible. Test each bird twice. 4). The most successful bird is the one that can fly the farthest. Mark which chick was the most successful on the tally sheet provided. 5). The most successful bird is the sole parent of the next generation. Use the measurements from this bird to be the parent of the next generation. The following generation will be continuing to breed, test, and record data for as many generations as you can in the time allotted. Use the table to record the results of your coin flips and die throws, the dimensions of all chicks, and the most successful bird in each generation. Extensions and assessment You can use the following questions for discussion of the topic. These can either be turned in for credit or can be discussed during the next class period. 1. Did your experiment result in better flying birds? 2. Evolution is the result of two processes: variation and selection. a. How did your experiment produce variation among the offspring? b. How did your experiment select offspring to breed the next generation? 3. Compare your youngest bird with your neighbor’s youngest bird. a. Compare and contrast the wings of of other birds with your own. b. Explain why some aspects of the birds are similar. c Explain why some aspects of the birds are different. 4. Predict the appearance of your youngest bird’s descendants if: a. the selection conditions remain the same and the longest flying bird survives to produce the most .offspring. b. the selection conditions change the worst flying bird survives to produce the most offspring. c. the selection conditions change and the bird whose color blends with its environment survives to .produce the most offspring. 5. Predict how the Aves hawaiiensis might adapt after the alchialine pools have disappeared from over development?

Name ___________________ Date _____________________

Origami Bird Data Sheet

Flip coin, throw die, record results. Plan the baby chicks, record their dimensions, breed the chicks. GENERATION 0: _kk Mark the winning bird. Only the most successful bird becomes a parent of the next generation. The “no mutation” chick in the next generation is identical to the winning bird in the immediately preceding generation. Continue to flip and throw, plan chicks, breed them, and test them for more generations.

No Mutation COIN COIN 3 x 20 3 x 20 _________x _________ x Head k Tail Head Tail Head Tail DIE DIE 3 cm 3 cm

Natural Selection Concepts Changes to the environment may affect how an organism may survive in the wild. Occasionally, organisms have the ability to activate different phenotypes in response to its changing surroundings. This lesson uses an endemic Hawaiian tree species, Ohia, to show how this species changes its phenotype in response to different habitat requirements. Standards addressed 7.5.4, 7.5.6 Duration 1 full day for field trip Vocabulary Natural selection Phenotype Genotype Glabrous Pubescent Phenotypic plasticity Source Material PRISM

Exploring the Ohia Common Garden

Summary After students have a strong understanding of Adaptations and Genetic Variation, they will be introduced to Natural Selection. They will visit the Ohia Common Garden in Volcano, Hawaii to see how Ohia (Metrosideros polymorpha) from different elevations have morphological differences. Objectives

• Students will simulate how genes are passed from one generation to the next.

• Students will understand how traits that are favorable for survival become more common over generations.

• Students will know that both genetic variation and environmental factors causes of evolution and species diversity.

Materials Background information about Ohia to lecture students before visiting garden Permission to visit the garden Dr. Elizabeth Stacy-can give presentation at garden about Ohia Background Biological evolution, which is the gradual change to a population of species over many generations, is the process responsible for the diversity of species. Natural selection is the process by which favorable traits that are passed on over generations become more common in a population of reproducing organisms. Natural selection is also responsible for how unfavorable traits (not conducive for survival) become less common in the population. This process acts upon the phenotype or the morphological characteristics of an organism. Organisms that have favorable phenotypes that allow them to survive and reproduce in the wild are more likely to survive than organisms that have unfavorable phenotypes. If the phenotype is based on genetics, then the genotype associated with that favorable phenotype will increase in frequency in the next generation and generations to follow. Natural selection also acts upon populations, not individuals alone. The changes to the phenotype and genotype must affect the entire populations of organisms, not just select individuals of the population. Ohia lehua (Metrosideros polymorpha) is a Hawaiian endemic plant found in almost all Hawaiian ecosystems. It is present on all Hawaiian islands, except Niihau and Kahoolawe. Ohia is an extremely variable plant that ranges in elevation from sea level to approximately 7000 feet. In order for Ohia to survive and reproduce at such drastic environments, species at different elevations have morphological differences. Ohia found at low elevations have larger, glabrous (smooth with no hair) leaves while ohia at high elevations have smaller, pubescent (with short fuzzy hair) leaves. One reason ohia at high elevations have smaller, fuzzy leaves is because they are closer to the sun and the fuzzy hair might protect the leaves from cold temperatures. Lower elevation Ohia are further from the sun and need a larger surface area to collect more sunlight and they are without fuzzy hair because they live at warmer temperatures. Ohia have a given phenotype, but also have the ability to change its phenotype in response to environmental changes. This phenomena is called phenotypic plasticity.

PRISM UHH GK-12

Teacher Prep for Activity Weeks prior to the field trip, Dr. Elizabeth Stacy at the University of Hawaii, Hilo must be contacted for access into the common garden. Dr. Stacy could possibly be available to meet with the students to discuss Ohia and natural selection also. Her contact information is: Elizabeth Stacy, Assistant Professor Department of Biology, University of Hawaii 200 West Kawili Street Hilo, Hawaii 96720, Email: estacy@hawaii.edu. Please give yourself many weeks to months in advance to plan this field trip. Procedure After finalizing the plans to visit the Ohia common garden, give the students some background information on Ohia before visiting the garden. At the garden, Dr. Stacy will talk about Ohia and its morphological differences. After the lecture, students will be split into groups and be asked to examine the different trees at the garden. They will be asked to collect a single leaf from a tree from high elevation, mid elevation and low elevation. After they have collected their leaves, they will be asked to explain why they think the leaves they collected belong to their respective habitats. After the field trip is completed, have the students write a reflection about their trip to the garden. They could also be asked to research another organism that displays phenotypic plasticity. Assessment Journal writing Written report of another organism that displays phenotypic plasticity. Extensions If the class is unable to visit the common garden or a project extension is needed, a possible class simulation of this exercise would be to grow tomato plants. Before growing the plants, ask the students if they think tomato plants (with the same genotype) grown in sunlight would look different from tomato plants grown without sunlight. Have them write down their predictions. Plant several plants in pots and place half the plants in direct sunlight and place the other half in the classroom, away from any light. Water and feed both sets of plants the same way. The plants grown in direct sunlight should grow upright, reaching for the sun while the plants grown inside should grow low, creeping along searching for sunlight. This simulation shows that different environmental factors can affect how an organism survives.

NATURAL SI

GOAL Natural Selection introduces students to natural selection as the mechanism that produces change in the genetic makeup of a population.

OBJECTIVES SCIENCE CONTENT

Environmental factors put selective pressure on populations.

Natural seletion is the process by which the individuals best adapted to their environment tend to survive and pass their traits to subsequent generations.

Members of a species are all the same kind of organisms and are different from all other kinds of organisms.

CONDUCTING INVESTIGATIONS Use a game simulation to experience change in a population, resulting from selective pressure.

Record and process information presented in a video about natural selection.

Use a multimedia simulation to explore the effects of natural selection on a population.

BUILDING EXPLANATIONS Describe how selective pressure can affect the genetic makeup of a population. Explain how the traits expressed by the members of a population can change naturally over time.

SCIENTIFIC AND HISTORICAL BACKGROUND It m a y be said that natural selection is daily Darwin brought his book to print. The

and hourly scrutinizing throughout the world, ideas disseminated quickly throughout the every variation, even the slightest; rejecting scientific community, and in their wake a

that which is bad, preserving and adding u p all new understanding of the progression of that is good; silently and insensibly working, life emerged.

whenever and wherever opportunity offers, at the improver~en t ofeach organic being i n relation to its organic and inorganic conditions

NATURAL SELECTION

of lqe. The idea is simple, really, and is -Charles Darwin

constructed on some fundamental

assumptions that have since been shown In 1831,22-year-old Charles Darwin to be sound. embarked on a 5-year voyage of discovery as resident naturalist aboard the survey ship Beagle. The impact of the incredibly diverse and complex biota he encountered in South America revolutionized his perception of life on Earth. During the voyage and the years following, Darwin formulated a theory explaining the uniqueness and origin of the organisms he discovered. It was many years, however, before he finally published his famous book, O n the Origin of Species by Means of Natural Selection, in 1859.

Darwin anguished over his manuscript. He was diligent in his science, wanting solid sources of evidence for his sveculative ideas. But even when the

Nature Produces Variation. During the process of reproduction, random changes occur in the genetic information directing the manufacture of a new unit-an offspring. Extreme changes are usually lethal, and no offspring result. Those genetic miscues are not perpetuated. Modest changes translate into often subtle and sometimes dramatic differences in individuals. Individual offspring turn out to be unique; one perhaps a little larger, another more aggressive, and still others darker in color, slower to respond, having larger fins or wider teeth, on and on. The result is variation in populations.

Life Is a Challenge. Many factors I converge to prevent organisms from

theory was clearly described and enjoying a peaceful, relaxed, successful

supported to h s satisfaction, he feared the existence. The physical environment can

societal response to his propositions. The be harsh, and is often variable. Weather

assumed affront to God, excused from the and catastrophe put pressure on

role of creator of all nature, and the organisms that can stress, weaken, and kill

reduced status of humanity, dismissed them. At the same time, nature produces

from the pinnacle of creation, troubled many more organisms than can be

Darwin. But when he found out that supported by the environment.

Alfred Wallace had reached essentially the Organisms that are not adapted to

same conclusions about natural selection withstand environmental pressures are

and was preparing to publish his work, doomed to fail.

Biotic factors put pressure on organisms. Heterotrophc organisms eat other

organisms for energy and building blocks. Organisms that fail to acquire food die.

On the other side of that equation, organisms that are taken for food also die. Microbes sometimes invade organisms, causing disease. Life is always under pressure.

Organisms in a Population Compete. Every species has a niche in which it lives and acquires the resources it needs for survival. The problem is, all the other members of an organism's species are trying to make a living in that niche as

well. This creates competition among members of a population for access to limited resources. If resources are not limited, members of the population could coexist without complications. Those individuals that succeed in getting resources and that successfully reproduce pass their genes to the next generation.

The measure of the success of an individual organism is whether or not it survives and reproduces. The traits that prepared a successful organism to

The measure of the success of a population

is its ability to withstand change in the environment and to prevail. Nature's

hedge against complete disaster imposed by disease, drought, or hoards of predators is variation. When a new pressure is imposed on a population, some individuals may succumb. But some will likely have adaptations that allow them to survive and reproduce more offspring than other individuals of that species. In this way the population continues, but

changes.

Darwin did not have the benefit of understanding the fundamentals of genetics, although it was well accepted that organisms passed the code for making reasonably accurate reproductions of themselves from generation to generation through sexual processes. He was able to observe firsthand the variation within a population, particularly when he observed the finches on the Galfipagos Islands. The puzzle that Darwin pursued was how the countless kinds of organisms came into being. What forces created a new kind of organism? What was the origin of species?

complete its destiny are passed to the next If a population existed in a constant, generation. Traits that resulted in supportive environment, natural processes successful reproduction by their parents would produce variation in the are, in all likelihood, the traits that will population, and the individuals would all increase the offspring's chances of have reasonable chances of survival. The reproducing. Successful individuals pass success of a varied population would the tools of success to their offspring. perpetuate a varied population.

As discussed earlier, however, the Pressure on the population might favor perversity of the physical environment some individuals over others because the and the pressures imposed by the biotic variations represent different adaptations, community don't allow for the idea of a and different adaptations affect the perfect organism, ideally equipped to potential for survival. So selective survive. Survival has to happen in a pressure on a population will favor some dynamic environment, so perfection is a

individuals, which will reproduce, influencing the distribution of traits in the

individuals. The population changes in response to selective pressure. (Notice, individuals don't change in response to selective pressure; they only survive or die. Populations change depending on the characteristics of the survivors.)

Over time a population may change sufficiently for science to judge it to be a different kind of organism than it was before the selective pressure was brought

to bear on the original population. How long does that take? And how different does the "new" population have to be to be deemed a new species?

It isn't easy to answer these questions. A new species may emerge in an extremely short time-a matter of days or weeks in

the case of bacteria. Or it may take millions and millions of years for a successful species like the white shark or horseshoe crab to change enough to be considered a new species.

Darwin observed the finches on the GalApagos Islands. The 20 or so islands are situated about 1000 km west of Ecuador. The current islands range in age from about 700,000 to 4 million years, but scientists suggest that there may have been other islands or sea mounts in the area as long as 10 million years ago. The point is that the GalApagos Islands are young, and any terrestrial life had to make its way there across the open sea or through the air.

Some time ago a single finch species arrived on the islands. Perhaps a small flock was blown off course in a storm. The birds apparently had no competitors for

resources, and they thrived. As time passed, variation entered the population. The most conspicuous variation was the beak. Different subgroups within the

population were better adapted to exploit different food sources. We can imagine that the members of the population that

sought similar food sources would associate, and other groups that shared different traits would associate. Feeding behavior isolated subgroups within the larger population. Breeding among the subgroup reinforced the trait that isolated it in the first place, further separating the subgroup.

Variation within the subgroup might have produced other traits that also tended to isolate the subgroup, perhaps coloration, size, nesting habits, mating rituals, and so forth. In time, isolation and change in response to pressures from the environment produced a new subspecies. The exact time at which a splinter group is awarded the status of species is a subject

for scientific debate. There are few absolutes for defining a species, so the moment at which it happens is nebulous.

Darwin concluded that speciation was a

natural outcome of ongoing life processes: (genetic) variation in a population, selective pressure in the environment, and

isolation of a segment of the population. Darwin's momentous discovery is often summarized as "survival of the fittest." This creates a mental image of a ferocious battle for survival, with the biggest, strongest, most voracious individuals always surviving to continue their kind. This is not an accurate picture. Fittest doesn't necessarily mean the individual in the best condition or the one with the

biggest teeth and strongest bones. It means the individual with the best adaptations to survive the pressure being

imposed by the environment. Fittest simply means the best equipped to survive and reproduce.

Who or what determines fitness? The selective pressure in the environment. The pressure might come from the weather. A return of the ice ages will select for those individuals with adaptations for surviving cold and select against those without adaptations for cold. A new predator that climbs trees will select for those tree- dwelling individuals that can flee or defend against the predator, and select against those that have no defensive adaptations. A drought that reduces the acorn crop may select for the smaller members of a population that can survive on less food and select against those that require more food. The result of natural selection is that the genetic makeup, and therefore the suite of traits expressed by the population, is constantly changing. The change process in organisms is called evolution. Organisms can be thought of as work in progress; they are constantly evolving from something into something else.

If you follow the evolutionary process back in time, perhaps 3.5 billion years or so, logically you eventually arrive at the first living organisms on Earth. Remember, life is the Olympic flame that burns in every organism. The flame is handed from one organism to the next. If

through millions and millions of handoffs without a fumble.

The processes of variation, natural selection, and isolation have produced an amazing array of organisms. There are millions of species alive on Earth today, and for each one there were at least a hundred species that are now extinct. The process of evolution has produced a continuous parade of new species, each adapted to the specific environments in which it lived, and continues to do so today.

ARTIFICIAL SELECTION

A discussion of artificial selection might shed light on the selection process. We humans have one adaptation (thanks to natural selection) that makes us a formidable organism to deal with-an advanced brain. We can control our environment to an unprecedented degree. As a result we can manage food resources, create shelter, manipulate energy, control other organisms, and re-create the world we live in.

One human enterprise is manipulating the traits of organisms through artificial selection. Think about the domestic dog. Every breed From the skinny, shivering Chihuahua to the robust, barrel-toting St. Bernard, and all the retrievers, hounds, terriers, poodles, spaniels, bulldogs, collies, and Pomeranians in-between are the same species. Where did all the diversity come from? Variation, selection, and isolation.

it goes out, it cannot be rekindled. Life Let's say you wanted to have a dog to

has only one chance to carry the torch, and catch squid for you. Where would you get

every organism guards it tenaciously as such a dog? Because there is no such dog,

long as it can. So every organism alive you would have to breed one. Squid live

today has received the precious fire

in the water, so you need a dog that is enthusiastic about water and swims well. A retriever or a spaniel would be a good breed to start with. So you get a bunch of

retrievers and spaniels and show them a squid. Toss the squid in the water and see whch dogs jump in to grab it. Of the original subset of water-loving dogs, only a few will pass the "goes for squid" test. Breed the squidophiles and raise the pups. Test them for squidophilia. Breed the most promising of those.

Take the best squidders out in a boat and see how good they are at spotting a squid in the water. Breed those with the best night vision. What's the best color (maybe black) and hair length (shorter the better). Identify those sharp-eyed squidophiles that have the darkest, shortest fur. The

animals that have the traits that fit your needs are the ones that you allow to reproduce to get more offspring with their traits.

After many generations of selective breeding you produce a squid hound, equal to the task you want it to perform. And if you find you are not completely satisfied with the dog's performance in the future (maybe the breed shakes after getting back into the boat after snaring a

dysfunction, or shvering, shows up as a trait in the breed, it may be difficult or impossible to breed it out without losing the traits you selected for in the first place.

A reduced gene pool caused by inbreeding often introduces vulnerability and weakness into the breed, due to lack of variation.

Artificial selection has been used for years to develop disease-resistant strains of grains, higher-yielding corn, faster- maturing soybeans, square tomatoes, seedless watermelons, and hundreds of other agricultural plants. And, of course, horses and livestock are selectively bred for a variety of functions and products, and the celebrated silk moth and the large and exotic goldfish called koi have been selectively bred for centuries to produce the living products we see today.

Nahire does the same, but without purpose, allowing some individuals with the right stuff to produce more offspring than others in the population. But in nature, the selection is based on passing a test, not possessing arbitrarily desirable traits. And the "right stuff" is having the traits that better prepare the offspring to survive and reproduce, not measuring up to a set of predetermined criteria.

squid), you can always continue to tinker You've heard the lament, "Just when I

with the traits to make it "better" by learned the answers, they changed all the

breeding members of the isolated questions." That's the way it goes out

population that have the desirable trait, in there in the biosphere--every time an

this case, stand and drip. organism "gets it right," the environment

There is danger in this process. By changes the test, so the winner yesterday isolating a small population, you may not have the right stuff to win today. significantly reduce the diversity in the That's natural selection, and that's what gene pool. If a genetic weakness, such as a keeps life evolvkg on Earth. tendency to bite, kidney disease, joint

WHY DO I HAVE TO LEARN THIS? This investigation presents some sensitive encourage students to engage them and issues. The ideas of natural selection and incorporate them into their growing

evolution of life on Earth can bring catalog of shared human knowledge. scientific historical evidence and the very For a full discussion of the issues essence of scientific inquiry into conflict associated with the teaching of natural with deeply held beliefs concerning the

selection, biological evolution, and the sacred origins of life. Both points of view

origin of species, obtain this book or seek to answer the same questions, in a browse it on-line: Teaching about Evolution way: How did I get and where did I and the Nalure of Science. Details are in the come from? References chapter. Evolutionary biologists study the scientific evidence provided by the inventory of living organisms, and piece together the fragments of life's prehstory, to synthesize a credible story for the emergence and progressive redesign of life on Earth. According to the biologst, the 3.5-billion- year ongoing experiment has produced Homo sapiens and the several millions of other species living on Earth today. And the biologist suggests that, just as it has from the beginning, the description, distribution, and diversity of life on Earth today is a snapshot of a work in progress. The evolutionary processes will continue to reshape the image of life on Earth indefinitely. We are here now simply as a result of chance and natural selection, just like every other living thng.

T h s course introduces students to the scientific explanation for the origin of species and, in the process, lays the groundwork for answering the questions of how I got here and where I came from. It is not the intent of this course to disparage the belief system of students. Rather, we present the science ideas and