unit 8: evolution chapters 14-17 - miss clark's...
TRANSCRIPT
1
Name: __________________________________________________________________
Unit 8: Evolution Chapters 14-17
Date Classwork Homework
Evolution Notes (Key points to Endosymbiont Theory) Read and answer questions to 14.1
Camouflage Animal PPT Fossil Activity
You are a Paleontologist A Timeline Activity Read and answer questions to 14.2
A Timeline Activity Finish Timeline questions
Start/Finish “Dating the Ice Man” Read and answer questions to 15.1
Evolution Illustrated Activity Read and answer questions to 15.2
Evolution Notes (Darwin to Non Random Mating) Go over Dating the Iceman Activity Reading and answering questions to 15.3
Molecular Analysis Activity Reading and answering questions to Ch. 16.1
Molecular Analysis activity Go over instructions for Natural Selection Activity
Natural Selection Color Blanket Activity Natural selection activity Complete natural selection activity
Evolution Notes (human evolution) Evolution worksheets
Complete worksheets Reading and answering questions to 16.2
Darwin’s Dangerous Idea Video Reading and answering questions to Ch. 16.3 Review Day Study for Test Test
Grades Out of Your Score
Evolution Notes 20 Fossil Activity 10 You are a Palentologist 20 Timeline Lab 20 Radiometric Dating 20 Natural Selection Activity 20 Molecular Analysis 20 Flow chart and crossword puzzle
20
Darwin Video 20 Total ---
2
Homework Chapter 14.1 Fossil Evidence of Change Before you read
1. Explain…:
2. Identify…:
3. Describe..:
4. Identify…:
5. Identify…:
6. Estimate…?
7. Describe..?
8. Sequence…?
9. Identify…?
10. Name…:
11. Label…?
12. Calculate…:
13. Label…?
14.2 The Origin of Life Before you Read
1. Explain…:
2. Describe…:
3. Determine…:
4. Identify…:
5. Explain…:
6. State…:
7. Sequence…:
8. Highlight…:
15.1 Darwin’s Theory of Natural Selection Before you Read
1. Name…:
2. Identify…?.
3. Explain….:
4. Identify…:
5. Contrast…:
15.2 Evidence of Evolution Before you Read
1. Identify…:
2. Define….?
3. Name…:
4. Define…:
5. Explain…:
6. Name…”
3
15.3 Shaping Evolutionary Theory Before you Read
1. Explain…:
2. Explain.
3. Draw Conclusions…:
4. Define…:
5. Evaluate…:
6. Highlight…:
7. Highlight…:
8. Evaluate…:
9. Identify…:
10. Apply…:
11. Explain…:
12. Define:…
13. Compare…:
16.1 Primates Before you Read
1. Label…:
2. Identify.
3. Drew Conclusions…:
4. Apply…:
5. Explain…?
6. Name…?
7. Identify…?
8. Study…?
9. Name…?
10. Explain…:
16.2 Hoinoids to Hominins Before you Read
1. Identify…:
2. Identify…
3. Highlight…:
4. Explain the difference…:
5. Summarize…
6. Draw Conclusions…?
7. Explain…
16.3 Human Ancestry Before you Read
1. Describe…:
2. Explain…
3. Describe…:
4. Generalize…:
5. Describe…
6. Highlight…?
7. Draw Conclusions…:
4
PowerPoint Notes
Key Points
Heritable characteristics increase or decrease an organisms chance of survival
Evolution is the change of the genetic makeup of a population over time
More closely related organisms have more closely related DNA and proteins
Many organisms have similar structures, and many organisms develop similarly
Mutations that lead to evolution occur randomly All species on earth are related by a common ancestor The fossil record shows organisms that are no longer alive Environmental pressures, genetic drift, mutation and competition for
resources lead to evolution
How did life on earth begin?
There are many theories Information about early earth comes from
_______________________ The earth is _____________________ years old The oldest clues about life on earth are ~3.5 billion
years old
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
5
Fossils
Fossils are ______________________ __________________of organisms
_________________ of all organisms are extinct Very __________________ organisms become
fossilized Many fossils are ________________________
Minerals fill in the areas where the organism was
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Dating Methods
A technique where items (rocks or fossils) are dated by comparing the soil layers
The Law of ___________ Sedimentary rock is
deposited in layers Older layers are deeper Newer layers are on top
Explain the picture?
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Dating Methods
Uses radioactive isotopes to date rocks or organic material Uses the ___________________________
of the isotope Carbon-14
Decays to Nitrogen-14 Half life is 5730 years Can date organisms up to 50,000 years
Potassium-40 Used to date older items Can only be used to date
____________________________ Half life is 1.3 Billion years
Radiometric Dating
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
6
Geologic Time
Represents major geologic events
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Spontaneous Generation-A Hypothesis
__________________________________________ -life arises from no life Francisco Redi’s experiment Redi’s experiment opposes the hypothesis
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Biogenesis- a theory
_____________________________ - life arises from life
Louis Pasteur – biogenesis is ____________ for microorganisms
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
7
Origins of Life
__________________________ organic molecule formation
Organic molecules could be ___________________ by simple reactions
UV light from the Sun and lightning may have been the primary _______________________ source
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Miller and Urey
Simple organic molecules are made from ______________ __________________
Conditions were like that of ______________ ______________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Cell Evolution
___________________________ evolved first Archea most closely resemble earth’s first life They are autotrophs, energy does not come from the
sun, they do not need oxygen
______________________________ prokaryotes evolved next Oxygen was just a byproduct
Eukaryotes evolved by prokaryotes developing _____________________________ relationships
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
8
Endosymbiont Theory
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Darwin & Natural Selection
Darwin was a ___________________ on the HMS Beagle He was also a companion to the captain He collected biological samples
Darwin collected many birds, mockingbirds and finches on the _________________________ Islands Each island had similar birds, but they
were slightly ______________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Artificial Selection andNatural Selection
Humans could changes species such as dogs by ___________________________ selection
Darwin’s Hypothesis
Support:
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
9
Natural Selection
Individuals in a population show ______________________________
Variations are _____________________________ Organisms have more offspring than can survive on
the available resources Variations that _________________________
reproductive success will have a greater chance of being passed on
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Support for Evolution
Fossils Fossils show species that lived ____________________ Ancient species share ___________________________
with living species
Glyptodont Armadillo
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Support for Evolution
_________________________________ : newly evolved features that do not appear in common ancestors Ie: _______________________________
Ancestral traits More _________________________ features that do
appear in ancestral forms
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
10
Homologous Structures
Anatomically ________________________ structures inherited from a common ancestor Structures are used for _________________________
purposes
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Vestigial Structures
Structures that are _____________________ in form They are useful in related
organisms
Features of ancestors that are _____________ ___________________ useful will become smaller or _______________over time
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Analogous Structures
Structures used for the same _____________________________ but are not from a common ancestor
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
11
Comparative Embryology
Vertebrate embryos look very similar as ________________
Develop ________________ as they get older
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Comparative Biochemistry
___________________________ ancestry can be seen in metabolic molecules DNA Amino acid sequences
More closely related organisms have ____________________ sequences
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
12
How Organisms Evolve
Genetic Drift
Change in ____________________________________ Caused by ______________ Seen in small populations
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
13
A small sample of a population __________________ to a new area
Alleles that were __________________ in the parent population become popular
The population almost goes ______________
A few surviving members survive and reproduce
Founder Effect Population Bottleneck
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
__________________ and emigration
__________________ variation within a population
Promotes ___________ Can cause alleles
frequency to ________ Female is usually
choosey Male usually displays
traits
Gene Flow Nonrandom Mating
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Types of Selection
The _____________ suited individuals survive
Derive a situation that could cause each graph.
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
14
Human Evolution
What is a primate (Ape) Manual dexterity Flexible bodies Limber shoulders and hips Large Brain Can solve problems Social Newborns dependent on mother Have fewer offspring
Are you an ape?
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
Humans
Bipedalism- changing environment Large Brain- evolved after bipedalism
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
15
Primate/Human Tree
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
___________________________________
16
Fossil Fun There are various fossils around the room. Visit each station and make a basic sketch of the specimen. Then answer the following Qs in the table below: 1. Is the specimen segmented (sections/chambers)?
(NOTE: Homo sapiens are segmented! head-thorax-abdomen) 2. What does the specimen have for support? (Internal skeleton? External calcium carbonate shell?
External chitin?) 3. Is there a living representative of this specimen today? If so, name it. 4. What geologic era does this specimen belong to?
(PreCambrian: soft-bodied life, Paleozoic: life flourished in the seas, Mesozoic: giant reptiles and life moved on to land and Cenozoic: all ice ages, mammals to present)
Specimen/
Lab # Drawing Q1 Segmentation
Q2 Support
Q3 Living?
Q4 Era
2
3
4
5
6
7
17
You are a Paleontologist How can fossilized bones suggest information about the evolutionary history of a species? Overview: You are going to take on the role of a paleontologist researching the history of birds, as you examine and piece together part of a skeleton from duplicate fossilized bones. Then you will compare the partial skeleton to skeletons of a modern-day alligator and bird. Introduction: Paleontologists observe skeletal features and make inferences about an animal’s behavior, such as how it moved and how it obtained food. Paleontologists compare similar skeletal structures of organisms to hypothesize the evolutionary relationships of species. In this lab, you will examine a partial skeleton of a dinosaur that shows several bird-like characteristics. Background: In 1964 scientist John Ostrom discovered the fossil skeleton that you will study in an area called the Cloverly Formation in Bridger, Montana. The area that Ostrom and his team prospected that field season had not yielded as many fossils as they had hoped. However, on the last day of the season, Ostrom discovered some bones he could not identify. The next year he returned to search for more of the skeleton. Eventually this newly discovered, extinct animal was named Deinonychus. Deinonychus lived during the early Cretaceous period, approximately 100 million years ago. It belonged to a group of dinosaur species called theropods, relatively small meat-eating dinosaurs that walked on 2 legs. The animal received its name, which means “terrible claw”, because the second toe on each of its hind feet had a large, sharp claw that probably was used to tear the flesh from prey. The claws were held up off the ground as the animal moved about, possibly preventing the claws from wearing down. As you will observe, Deinonychus’s skeleton shares many features of the skeletons of both modern alligators and birds. Many researchers hypothesize that the ancestor of birds was a feathered theropod. However, other researchers hypothesize that theropods and birds share common features because they had a common ancestor from which both lineages evolved separately. Much further research is needed to evaluate these 2 hypotheses. In this lab, you will model the work performed by paleontologists as you examine Deinonychus and identify the reptilian characteristics its skeleton retains as well as the bird like features it displays. In the prelab activity, read about how fossils are removed from the ground and how they are transported. Then answer the prelab questions. Prelab Activity: Removing fossils from rock is a long process that requires both skill and a lot of patience. First, the rock surrounding the top and bottom of the fossils is removed with large earth-moving equipment. Scientists use smaller equipment such as shovels, picks, and brushes when working close to a fossil. Before removing a fossil from the ground, workers must encase it in a plaster “jacket” to prevent it from crumbling during transport to the lab. After treating a fossil with glue to harden it, paleontologists cover the top of the fossil with tissue paper or foil to protect it from the plaster. The plaster is allowed to harden on the top and sides of the fossil. Then the paleontologist climbs under the fossil and frees it from the ground. The fossil is removed from the rock and flipped over so that plaster can be applied to the bottom side. In the lab, a person called a “preparatory” begins that long process of removing the plaster jacket and the small bits of rock still surrounding the fossil. The preparatory may use a microscope and tools as fine as needles to clean the fossils literally one grain of sand at a time. Once the bones are free from the rock, paleontologists may make casts of the bones to send to other paleontologists so they can collaborate in studying them.
18
Prelab Questions: 1. Describe the process by which paleontologists and their team remove fossils from rock. 2. Fossil skeletons are rarely complete. How do you think casts and collaboration help
paleontologists create more complex skeletal models? 3. What role do you think inferences play in the work of a paleontologist?
Materials: • Replica fossilized bone “casts” • Scissors
• Paper • Tape or glue
Procedure:
Part A: 1. Cut out the “casts” and spread them out on a flat surface. Note that this is only a partial skeleton.
Very seldom does a fossil dig produce a complete skeleton. In this fossil dig, for example, paleontologists were only able to obtain the limbs from the left side of the animal’s body. Try to fit the bones together. First, locate recognizable bones such as the skull and backbone.
2. Use the reference skeletons in Part B below to guide you in the placement of the other bones.
Collaborate with other groups if you cannot decide where to place a bone. 3. Once you have decided how the bones should be connected, tape or glue them in place on a piece
of paper.
Part B: Look closely at the scapula, sternum, tail, and feet of all 3 skeletons. Note that both Deinonychus and the bird have an extra toe that points backward. Fill in the data table on the next page by checking off which features you observe in each skeleton.
19
Data Table Characteristic Alligator Bird Deinonychus
Narrow scapula (shoulder blade)
Wide scapula (shoulder blade)
Prominent sternum (breastbone)
3 primary toes on hind feet
4 primary toes on hind feet
Extra toe that points backward
Hind legs underneath the body rather than to the sides
Long tail
Short tail
Claws on front feet
Claws only on hind feet
Bipedal (walks on 2 legs)
Quadrupedal (walks on 4 legs)
Teeth
20
Analysis and Conclusions: 1. Which part of the Deinonychus skeleton did you find most difficult to identify and put in place?
Explain. 2. Describe the features you observed that the Deinonychus skeleton has in common with that of a
modern day alligator. 3. Describe the features you observed that the Deinonychus skeleton has in common with that of a
modern day bird. 4. Scientists ask the following 2 questions when inferring whether some dinosaurs may have been the
link between ancestral reptiles and modern day birds: • Are there any fossil birds that retain more reptilian features than birds that are now living? • Are there any fossil reptiles that show more bird like features than any reptiles now living? • Does Deinonychus provide an answer to either of these questions? Explain?
5. Below, sketch an example of what you think the earliest bird may have looked like. Write a short
paragraph explaining the features of the bird in your sketch.
21
A Time Line
Overview: The Earth has changed dramatically and repeatedly over a history that spans nearly 5 billion years. Such immense spans of time are difficult for most of us to comprehend. They fall outside our range of human experience. We normally deal with much shorter time intervals, like the time of our next class or the number of days until the next test, or even the number of years until graduation! It is important for students of geology to expand their sense of time. Extremely slow geologic processes, considered only in terms of human experience, have little meaning. To appreciate the magnitude of geologic time and the history of our incredible planet, you will be creating a timeline of important geologic events scaled to a size more tangible and familiar. Prelab. Read through the lab and answer the following questions. Always remember to show math work, if appropriate and always, always, always include units with your final answer. 1. How many millions are there in a billion? 2. In lab, you will make a timeline 4.56 meters long to represent the 4.56 billion years of Earth’s history:
a) How long would 1 billion years be on the timeline?
b) How many years would 100 cm represent?
c) How many years would 1 cm represent?
3. Draw a line that is 1 cm long.
Instructions to make a scaled timeline. You will be making a timeline of Earth’s history on a long strip of adding machine tape. The timeline should be done to scale. Use the scale in which 1 meter equals 1 billion years. Therefore, each millimeter represents 1 million years. To do this you will:
a) Measure out a strip of adding machine tape 5 meters long. A meter stick will be provided in lab. b) Select one end of the tape to represent the Present. Beginning at that end, mark off each billion years (1
billion, 2 billion, etc.) c) Starting with the oldest event and mark off all of the important events in Earth’s history shown in Figure 1. In
each case you should write the date and event directly on the timeline. Add pictures to your timeline corresponding to the events.
d) Turn your timeline into your instructor on the date due.
22
Figure 1. Some Important Events in Earth’s History
Date in years before
present Event
4.56 billion
Earth forms
4.1 billion Oldest piece of rock ever found 3.9 billion Oldest evidence of a continent 3.4 billion First fossils (algae and bacteria) – Earliest evidence of life
543 million Paleozoic Era begins 460 million First fish 443 million First land plants 410 million First land animals 250 million Largest mass extinction occurs 248 million Mesozoic Era begins; Triassic Period begins 247 million First dinosaurs 240 million First mammals 206 million Jurassic Period begins 150 million First birds 144 million Cretaceous Period begins 65 million Dinosaurs and other animals go extinct; Cenozoic Era begins 65 million Primates appear 30 million Mammals/flowering plants become abundant 200,000 First humans 13,000 Humans first inhabit North America 8,000 Founding of Jericho, the first known city 500 European rediscovery of the Americas ~40 Humans first explore the moon
Analysis.
1. Which era is the longest? The shortest? _______________________________________________________
2. In which eras did dinosaurs and mammals appear on Earth? _______________________________________
3. What major group first appeared after dinosaurs became extinct? __________________________________
23
Real World Biology: Dating the Iceman
Radiometric dating techniques make use of unstable radioactive isotopes to measure the ages of objects from the geologic past. Isotopes are atoms of an element that have different numbers of neutrons in their nuclei. The neutrons and protons in the nucleus of an atom are usually held together by strong forces. In some isotopes, however, the forces are not strong enough to hold the nucleus together, and it breaks apart, or decays. This process is called radioactivity. When an atom of an element decays, an atom of a different element is often formed. For example, an unstable uranium atom decays to form a stable lead atom. The uranium atom is called the parent, and the lead atom is called the daughter. Every radioactive isotope decays at a constant rate that is characteristic of that isotope. Suppose a rock contains atoms of radioactive uranium (U-238). The parent uranium atoms have been decaying and daughter lead atoms have been accumulating at a constant rate since the rock was formed. The time required for one-half of the nuclei in a sample to decay is called the half-life of the isotope. It takes 4.5 billion years for half the U-238 atoms in a rock to decay into lead atoms. After one half-life, the numbers of U-238 atoms and lead atoms in the rock are equal. After two half-lives, there is one U-238 atom for every three lead atoms. Part A: Radiocarbon Dating High-energy radiation from the Sun causes atoms of a radioactive isotope of carbon, carbon-14 (C-14), to form in the atmosphere. These atoms combine with oxygen to form radioactive carbon dioxide, which is taken in by plants and incorporated into plant tissue. Thus, C-14 enters the food chain and carbon cycle along with common C-12 atoms. There is little radioactive carbon in living things—about one atom of C-14 to one trillion atoms of stable C-12. When an organism dies, carbon no longer is taken into its body, and any C-14 present continues to decay, forming a nonradioactive isotope, nitrogen- 14 (N-14). Because the half-life of C-14 is relatively short, it can be used only to date material that is less than 100,000 years old. Suppose that an ancient human once lit a campfire in a cave dwelling and that you analyze some charcoal from that fire. The charcoal contained 100 g of C-14 when the fire was lit. The half-life of C-14 is 5730 y.
1. Complete Table 1. Note that C-14 and N-14 have the same atomic mass.
2. On the grid to the right, graph the data in your table to show the relationship between the passage of time and the amount of C-14 in the charcoal sample. Time 0 is the point at which radioactive decay begins. The 28,650-year point is the present time.
24
Analyze and Conclude. Respond to each question or statement.
1. Explain whether carbon-14 can be used to find the ages of rocks. _________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
2. Evaluate Why is radiometric dating more accurate than relative dating, which uses the law of superposition?
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
Part B: Dating Ötzi, the Iceman On September 19, 1991, an amazing discovery was made in the mountains between Austria and Italy. Two hikers found an ancient mummified body that was partially embedded in melting glacial ice. The Iceman, as he was called first, was later nicknamed Ötzi after the mountain range in which he died. At first, Ötzi was believed to be about 500 years old, but when scientists saw the tools that were found near the body, they realized that he was older. Radiometric analysis of Ötzi’s bones and hair and the grass in his shoes showed that their carbon-14 content was 53 percent of what it would have been before death. Analyze and Conclude. Use Table 2 to respond to each question or statement.
1. Identify the geologic era in which Ötzi lived. ___________________________________
2. Calculate If a sample of wood from one of Ötzi’s tools is found to contain only one-fourth as much carbon-14 as a sample from a living tree, what is the estimated age of the wood in the tool?
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
3. Infer Why did scientists use carbon-14 to establish Ötzi’s age instead of using the other isotopes listed in Table 2?
_________________________________________________________________________________________
_________________________________________________________________________________________
_________________________________________________________________________________________
25
Figure 1. Spread 10 dots of each color
How is camouflage an adaptive advantage?
Natural selection can be described as the process by which those organisms best adapted to the environment are more likely to survive and reproduce than are those organisms that are poorly adapted. Organisms have developed many different kinds of adaptations that help them survive in their environments. These include adaptations for finding food, such as keen night vision in nocturnal animals, as well as adaptations for avoiding predators. Some organisms use camouflage as a way to escape predation from other organisms. Camouflage allows them to blend in with the background. Objective:
In this investigation, you will • use an artificial environment to model the concept of natural selection. • hypothesize what will happen if natural selection acts over time on organisms exhibiting camouflage • construct bar graphs to show the results of the investigation. • compare the model of natural selection in the investigation to real examples of natural selection.
Materials: • hole punch • colored paper (1 sheet each of purple, brown, blue, green, tan, black, orange, red, yellow, and
white) • plastic film canisters or petri dishes (10) • piece of brightly colored, floral fabric (80 cm X 80 cm) – each fabric represents a different biome. • graph paper (2 sheets)
Procedure
1. Work in a group of four students. 2. Use the colored dots provided in the paper bag or plastic cup. You should have at least 20 dots of
each color. 3. Spread out the floral cloth on a flat surface. Identify your biome: _______________________. 4. Spread 2 dots of each color randomly over the cloth. See Figure 1. 5. Select a student to choose dots. That student must look away from the cloth, turn back to it,
and then immediately pick up the first dot he or she sees. 6. Repeat step 5 until 10 dots have been picked up. Be sure the student looks away before a
selection is made and the rotate the fabric each time. 7. Record the results in Table 1. Return the 10 collected dots to the
cloth in a random manner. Assume that the dots represent individual organisms that, if allowed, will reproduce more of their own type (color). Also assume that the selection of dots represents predation.
8. Write a hypothesis to predict what will happen over time if selected dots are not returned to the cloth and the remaining dots “reproduce.” Write your hypothesis in the space provided under Data and Analysis.
26
Figure 2.
Surviving Dots
Number of Dots Remaining After Each Generation
Color Number remaining after generation
1 2 3 4
Purple
Brown
Blue
Green
Tan
Black
Orange
Red
Yellow
White
Start Over… 2 Dots of each colors on fabric.
9. Each student in the group must, in turn, pick up 10 dots following the method in steps 5 and 6. Place the dots in their original containers. Remember to look away each time before making a selection and rotate the fabric.
10. After the first student has removed 10 dots shake the remaining 10 dots off the cloth onto the table. See Figure 2.
11. Count and record in Table 2 the number of dots of each color that remains.
12. Give each of the “surviving” dots one “offspring” of the same color by adding dots from the containers. You may need to punch out more of certain colors. Return all of the dots to the cloth in a random manner.
13. Repeat steps 9–12 three more times (1 person each time). Each repetition represents the survival and reproduction of a single generation. Continue to record the results of each repetition in Table 2.
14. Make a bar graph in the space below to show the number of dots of each color that were on the cloth at the beginning of the Investigation. Label the horizontal axis with the names of the 10 colors and the vertical axis with the number of dots.
Data: Table 1. Table 2.
Selection of Dots
Color
Number of dots selected
Purple
Brown
Blue
Green
Tan
Black
Orange
Red
Yellow
White
27
Data and Analysis 1. Make a bar graph of the data in Table 1.
2. Make a second bar graph in the space to the right to show the number of dots of each color that were on the cloth at the end of the fourth generation. Label the axes as on the first graph.
3. Hypothesis:
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
4. Which colors were picked up from the floral background?
_____________________________________________________________________________________
____________________________________________________________________________________
5. Which colors, if any, were not picked up? Why not?
_____________________________________________________________________________________
_____________________________________________________________________________________
28
6. If the dots represent food to a predator, what is the advantage of being a color that blend in with the background? _____________________________________________________________________________________
_____________________________________________________________________________________
7. Give two examples of real organisms that use camouflage to avoid predation.
_____________________________________________________________________________________
_____________________________________________________________________________________
8. As the dots on the cloth passed through several generations, what trends in frequency of colors
did you observe? _____________________________________________________________________________________
_____________________________________________________________________________________
9. How would the outcome of this Investigation have differed if the “predator” was color-blind?
Explain. _____________________________________________________________________________________
_____________________________________________________________________________________
10. How would the outcome of this Investigation have been affected if dots that were subject to
predation (those picked up) tasted bad or were able to harm the predator in some way, such as by stinging it?
_____________________________________________________________________________________
_____________________________________________________________________________________
11. Describe an example of natural selection that is similar to the model of natural selection in this
investigation.
_____________________________________________________________________________________
_____________________________________________________________________________________
12. Was your hypothesis supported by your data? Why or why not?
_____________________________________________________________________________________
_____________________________________________________________________________________
39
Biochemical Evidence for Evolution
If two organisms have similar DNA molecules, they have similar proteins. Similar proteins have similar amino acid sequences (orders). Thus, if amino acid sequences are similar, DNA of the organisms is similar. Some scientists believe that similar DNA sequences indicate a common origin. The more similar the DNA of two living organisms, the more closely related they may be to one another. Hemoglobin, a protein in red blood cells, has been studied. Scientists know the specific amino acids and their arrangements in hemoglobin molecules of humans, gorillas, and horses. Objective:
In this investigation, you will • count and record differences in the sequence of amino acids in similar portions of human, gorilla, and
horse hemoglobin. • count and record the molecules of each amino acid present in similar portions of human, gorilla, and
horse hemoglobin. • use these data to show how biochemical evidence can be used to support evolution.
Procedure: Part A: Amino Acid Sequence
Figure 2 represents the amino acid sequence of corresponding portions of the hemoglobin molecules of horses, gorillas, and humans. 1. Read the amino acid sequences from left to right beginning at the upper left-hand comer of Figure 2.
Compare the sequences of humans to the sequences of gorillas and horses. An example of a sequence difference between humans and gorillas is shown in Figure 1.
2. Record in Table 1 the total number of differences in the sequences of gorilla and human amino acids. Then repeat this procedure for horse and human, and for gorilla and horse.
Part B: Numbers of Amino Acids
1. Count the number of each kind of amino acid in human hemoglobin. Record the totals in the proper column of Table 2.
2. Count each amino acid in the hemoglobin of gorillas and horses. Record these in Table 2. Figure 1
40
Biochemical Evidence for Evolution
Figure 2 Human: Gorilla: Horse:
Val Val Val
His His Glu
Leu Leu Leu
Thr Thr Ser
Pro Pro Gly
Glu Glu Glu
Glu Glu Glu
Lys Lys Lys
Ser Ser Ala
Ala Ala Ala
Val Val Val
Thr Thr Leu
Ala Ala Ala
Leu Leu Leu
Try Try Try
Human: Gly Lys Val Asp Val Asp Glu Val Gly Gly Glu Ala Leu Gly Arg Gorilla: Gly Lys Val Asp Val Asp Glu Val Gly Gly Glu Ala Leu Gly Arg Horse: Asp Lys Val Asp Glu Glu Glu Val Gly Gly Glu Ala Leu Gly Arg
Human: Leu Leu Val Val Tyr Pro Try Thr Glu Arg Phe Phe Glu Ser Phe Gorilla: Leu Leu Val Val Tyr Pro Try Thr Glu Arg Phe Phe Glu Ser Phe Horse: Leu Leu Val Val Tyr Pro Try Thr Glu Arg Phe Phe Asp Ser Phe
Human: Gly Asp Leu Ser Thr Pro Asp Ala Val Met Gly Asp Pro Lys Val Gorilla: Gly Asp Leu Ser Thr Pro Asp Ala Val Met Gly Asp Pro Lys Val Horse: Gly Asp Leu Ser Asp Pro Gly Ala Val Met Gly Asp Pro Lys Val
Human: Lys Ala His Gly Lys Lys Val Leu Gly Ala Phe Ser Asp Gly Leu Gorilla: Lys Ala His Gly Lys Lys Val Leu Gly Ala Phe Ser Asp Gly Leu Horse: Lys Ala His Gly Lys Lys Val Leu His Ser Phe Gly Glu Gly Val
Human: Ala His Leu Asp Asp Leu Lys Gly Thr Phe Ala Thr Leu Ser Glu Gorilla: Ala His Leu Asp Asp Leu Lys Gly Thr Phe Ala Thr Leu Ser Glu Horse: His His Leu Asp Asp Leu Lys Gly Thr Phe Ala Ala Leu Ser Glu
Human: Leu His Cys Asp Lys Leu His Val Asp Pro Glu Asp Phe Arg Leu Gorilla: Leu His Cys Asp Lys Leu His Val Asp Pro Glu Asp Phe Leu Leu Horse: Leu His Cys Asp Lys Leu His Val Asp Pro Glu Asp Phe Arg Leu
Human: Leu Gly Asp Val Leu Val Cys Val Leu Ala His His Phe Gly Lys Gorilla: Leu Gly Asp Val Leu Val Cys Val Leu Ala His His Phe Gly Lys Horse: Leu Gly Asp Val Leu Ala Leu Val Val Ala Arg His Phe Gly Lys
Human: Glu Phe Thr Pro Pro Val Glu Ala Ala Tyr Glu Lys Val Val Ala Gorilla: Glu Phe Thr Pro Pro Val Glu Ala Ala Tyr Glu Lys Val Val Ala Horse: Asp Phe Thr Pro Glu Leu Glu Ala Ser Tyr Glu Lys Val Val Ala
Human: Gly Val Ala Asp Ala Leu Ala His Lys Tyr His Gorilla: Gly Val Ala Asp Ala Leu Ala His Lys Tyr His Horse: Gly Val Ala Asp Ala Leu Ala His Lys Tyr His
41
Data and Analysis:
Table 1
Number of Amino Acid Sequence Differences
Organisms
Number of Differences
Gorilla and human
Horse and human
Gorilla and horse
Table 2
Number of Each Amino Acid
Amino Acid Abbreviation Human Gorilla Horse
Alanine
Ala
Arginine Arg
Aspartic acid Asp
Cysteine Cys
Glutamic acid Glu
Glycine Gly
Histidine His
Leucine Leu
Lysine Lys
Methionine Met
Phenylalanine Phe
Proline Pro
Serine Ser
Threonine Thr
Tryptophan Try
Tyrosine Tyr
Valine Val
42
1. Where is hemoglobin normally found? ______________________________________________________
2. How many different kinds of amino acids are present in these three animals’ hemoglobin? ____
3. (a) Which amino acid is most common in all three animals? _____________________________________ (b) Which amino acid is the least common in all three animals? __________________________________
4. Use your data from Table 1 to answer these questions.
a. How similar are the ammo acid sequences of human and gorilla hemoglobin? _____________
b. How similar are human and horse hemoglobin? _______________________________________
c. How similar are gorilla and horse hemoglobin? ________________________________________
5. Of the different types of amino acids found in hemoglobin,
a. how many are present in the same exact number in humans and gorillas? ___________________
b. in humans and horses? _____________________________________________________________
c. in gorillas and horses? _____________________________________________________________
6. On the basis of your answer to question 5,
a. how similar are the chemical makeups of human and gorilla hemoglobin? ___________________
b. how similar are human and horse hemoglobin? _________________________________________________________
c. how similar are gorilla and horse hemoglobin? _____________________________________
7. Which two animals seem to have more similar hemoglobin?
8. In numbers, explain how the base sequences (genes) for hemoglobin formation on human chromosomes differ from those in gorillas. (How many bases are different?)
9. Give reasons for supporting or rejecting the following statement. Upon examination, segments of human and gorilla DNA responsible for inheritance of hemoglobin should appear almost chemically alike. ____ __________________________________________________________________________________________________________________________________________________________________________________
10. Give reasons for supporting or rejecting the following statement. Evolutionary relationships are stronger between living organisms which have close biochemical (protein) similarities than between living organ- isms which do not have close biochemical similarities. ____ __________________________________________________________________________________________________________________________________________________________________________________ ____ _________________________________________________________________________________________
43
Video: “Darwin’s Dangerous Idea” Answer the following questions while watching the video.
1. What kind of birds did Darwin study
2. What cause did Darwin give for the birds being different?
3. What bird did all of the other birds descend from?
4. Darwin though all plants and animals branched from what structure?
5. What geographical area does Chris Schneider and Tom Smith study for evolutionary information?
6. What was unique about the finches’ beaks?
7. How many degrees can a hummingbird’s temperature drop to survive the mountain temperatures at night?
8. What tool do we have that Darwin didn’t have to compare the ancestry of living things?
9. How long ago did lowland and highland hummingbirds diverge?
10. What blood relation is Emma to Charles?
44
11. How many different drugs has Jeff Gustafsen used in over 10 years of living with AIDS?
12. How many AIDS drugs are there?
13. What process changes HIV?
14. Natural Selection favors ____________ ____________ forms of HIV.
15. Is there any predictability for how or when “accidents” happen?
16. What was Dr. Miller’s new strategy for treatment of HIV patients?
17. What primitive animal shows a less evolved cup eye?
18. What structure in the eye helps us focus better than primitive eyes?
19. What did Darwin’s daughter Annie die of?
20. Did it really have anything to do with Darwin being married to his cousin?
Evolution Concept Map
Evolution Crossword
Across: 2. Structures that are similar 5. A characteristic that helps an organism survive 9. When one species evolves into many: adaptive ____________ 10. Pattern of evolution where a species is stable for a long time then rapidly changes: ____________ equilibrium 12. The name of Darwin’s book: The ____________ of Species 13. Process by which evolution occurs: natural ____________________ 17. Had different shaped shells depending on the island they were from 18. Well-supported testable explanation 20. When two species evolve together 21. Natural selection is also known as the survival of the ___________ 22. Islands that Darwin visited 23. Principle that states that living species are descended from ancient ones: decent with ____________ 24. The name of the ship that Darwin traveled on
Down 1. When two unrelated organisms look alike (sharks/dolphins) 3. Refers to the variety of living things 4. When organisms disappear from the earth 6. Proposed the theory of evolution by natural selection 7. Formation of new species 8. Change over time 11. Required for new species to form 14. Preserved remains of ancient organisms 15. Had different shaped beaks depending on the island they were from 16. The study of the earth 18. Structures that have no current function