unit 2 ~ learning guide name:bclearningnetwork.com/lor/media/bi11/learning_guides/bi11_lg_u… ·...

BCLN BIOLOGY 11 – Rev July 2014

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Unit 2 ~ Learning Guide Name: _______________ INSTRUCTIONS Complete the following notes and questions as you work through the related lessons. You are required to have this package completed BEFORE you write your unit test. Do your best and ask questions about anything that you don't understand BEFORE you write the unit test.

2.1 NOTES: EVIDENCE OF EVOLUTION

YOU SHOULD WATCH THE TINTRODUCTION TO EVOLUTION UNIT VIDEO BEFORE PROCEEDING ANY FURTHER!

Development of a Theory More than anyone else, a young Englishman named ___________________________________ made great contributions to our understanding of _______________________. In 1831 he set sail on the ___________________ to travel the world. During his 5 year voyage Darwin's observations helped him to realize that an _________________________________________________ _____________________________________. He also realized that the diversity of life he observed was only one part of a much larger puzzle. __________________

_________________________________________________________________________________________. As a result of these observations Darwin sought to answer two questions: Firstly, "Where did all of these different organisms come from?" And secondly, "Why have so many of them disappeared over time?"

Darwin was also impressed by the many ________________ ______________________________________ that enable organisms to _____________________________________ _______________________ in their environment. He termed this ____________________. Darwin also wondered ________________________________________________________________________________________________________________________________________________________________________________________________


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30 years after working to answer these questions, Darwin published his book called ________________________________________________________________________________________________________. This book changed the way people think about the living world. In his book Darwin maintained that modern organisms were produced by a process call ___________________________________.

YOU SHOULD WATCH THE HOW DO WE KNOW EVOLUTION HAPPENS VIDEO BEFORE PROCEEDING ANY FURTHER!

What is Evolution?

The idea that life on Earth has changed over time, is very old. Scientists have accumulated considerable evidence to show that organisms alive today have been produced by a long process of change over time. The process by which modern organisms have descended from ancient organisms is called ____________________. Evolution, in the broadest sense, simply means _____________________ but is better known by the following definitions:

"A __________________________________________ in which something changes into a different and usually _______________________________________________ _________________" - answers.com

(i.e., all organisms come from a common ancestor) "Evolution: The gradual process by which the _______________________________ __________________________________________________________________________________________________________________________________________, which is believed to have been continuing for the past _____________ ______________________________." - Oxford Concise Science

This unit will have a look at the highly debated topic of Evolution. Theory or not? That will be for each of you to decide for yourselves as you work through the assignments.

Evidence Supporting Evolution:

1. Fossil record. 2. Biochemical and Molecular Biology. 3. Biological Evolution. 4. Biogeography. 5. Embryology and development. 6. Comparative Anatomy.

YOU SHOULD WATCH THE EVIDENCE FOR EVOLUTION VIDEO BEFORE PROCEEDING ANY FURTHER!


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The Fossil Record

Layers of __________________________ contain _______________.

New layers _________________________, creating a ___________________________ _________________________.

Fossils are _________________________ __________________________________. Most fossils are formed from being covered by sediment. The soft parts of an organism most likely will be decomposed, however sometimes they leave an ______________________ if covered quickly. ___________ ____________________________________________________________________.

______________________________________ is found in the strata of the sedimentary rock ___________________________________________, and _______ ___________________________________________. Fossils within layers show that a succession of organisms have populated Earth throughout a long period of time.

Dating fossils is a very difficult process. Scientists use _________________________ _____________________________ to date fossils. Isotopes have a half-life measured in time. This means that after a period of time (half-life) the original radioactive isotope will decrease by half the original sample allowing scientists to estimate time periods. For example, Carbon 14's half-life is 5,730 years.

The fossil record is a record showing us that today’s organisms __________________ ________________________________________________

2.1 PRACTICE PART 1 of 3: EVIDENCE OF EVOLUTION

YOU SHOULD CLICK ON THE LINK FOR ASSIGNMENT 1. AFTER REVIEWING ALL THE INFORMATION IN THE LINK COMPLETE THE SECIAL ASSIGNMENT

AND SUBMIT YOUR HYPOTHESIS IN A WORD DOCUMENT TO THE DROP BOX BEFORE PROCEEDING ANY FURTHER!

http://www.ucmp.berkeley.edu/education/explorations/reslab/flight/index.htm


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Archeopteryx

The illustration below is of Archeopteryx. It represents a __________________________________________________________________________ found in an area of present day Germany. Archaeopteryx many have been a ______________ _________________________ that provides evidence of an evolutionary connection between primitive ________________ ______________________. The fossil has _______________ __________________________________________________________________________. Other examples of transitional animals are Eustheopteron, a lobe finned fish ancestral to amphibians, and Seymouria, an amphibian ancestral to reptiles. The fossil record can help _______________________________________________ ______________________________________________________. The diagram below shows the changes in elephants over the past 25 million years.

Biochemistry and Molecular Biology

______________________ consists of cells. The __________________________ _________________. DNA is _____________________________________________ _____________________________.

______________________________ in both DNA and other chemical compounds ____________________________________________________________________.


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__________________ (Deoxyribonucleic Acid) _____________ ____________________________________________ building blocks called __________________________. These nucleotides are composed of ________________ (deoxyribose) and _______________________________ which make up the backbone of the double helix, ________________________ ______________________________________________________________________________________________________ that make up the rungs of the DNA ladder. The four bases _______________ pair up in the following way: ____________ ______________________________. This if referred to as ___________________________________. The ___________ _____________________________ of A's, C's, G's, and T's is what makes the organism a dandelion or a human. ___________________________ ___________________________________________________________________

YOU SHOULD CLICK ON THE LINK AND READ THE HUMAN EVOLUTION

ARTICLE BEFORE PROCEEDING ANY FURTHER! Therefore, it is the _______________________________ __________________________________________________________________________________________________________________________________________________. For example, the DNA difference between humans and chimpanzees is __________ but the difference between humans and lemurs is ________. This displays a closer relationship between _______________________________ _______________________________________________. Biochemical similarities between organisms are closely related to the _________________________________ _______________________ they possess. The role of DNA in evolution is clear. __________________ _________________________________________________________________________________________________. These changes in DNA provide __________________ within organisms upon which _____________________________ _______________________________________________. Other biochemical compounds such as similarities in specific proteins found in different species can also suggest an evolutionary relationship.


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For example, let's use the protein Hemoglobin that carries oxygen in our red blood cells. ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________ Biological Evolution The change of ________________________ of organisms ______________________________. A population is a group of members of _____________________________________ ________________________________________________________________________________________________________________________________________________.

Small changes in many species have been observed throughout time. However, the change or ________________ ____________________ has often been _____________ ______________________. Many organisms such as specialized dog breeds or crop plants look very little like their ancestors. These organisms were _______________________ to have a specific ___________________ __________________________. Other organisms have changed due to human influence with less conscious human intervention. For example, ________________________________________________ _______________________________________________________________________________________________________________________________________________________________________________________. The population changed due to the white moths being selected against. Examples like the peppered moth show us that _________________________ have the ability to ______________________ with changing environments so this is a likely reason for the diversity of life on earth today.


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2.1 PRACTICE PART 2 of 3: EVIDENCE OF EVOLUTION Click on the Peppered Moth link and attempt a simulation activity. Use what you learn to answer the following questions:

1. How did pollution affect the peppered moth population in industrial England? (1 mark)

2. Explain the process that led to these changes in the moth population? (3 marks)

3. What do you anticipate would happen to a predominantly light colored peppered moth population if a new form of lichen were to take over the tree bark? This new lichen is neither light nor dark. (3 marks)

http://peppermoths.weebly.com/


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Biogeographical Evolution

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

______________________________________________________________________

Where these plants and animals are distributed is related to their evolutionary history. Organisms evolve in one location and may move into other areas. For example, rabbits are not found in South America. These rabbits must have evolved somewhere else and did not reach South America.

The _____________________________________________ can explain the reasons why some organisms ____________________________________________________ __________________________. The Continental Drift Theory refers to the observation

that the _____________________________________________________________

___________________________________________________________________________________________________________________. This theory explains the close _______________________________________________ of the east coast of South America with west coast of Africa and other continental edges. __________________ ___________________________________________________________________ ___________________________. It also explains the distribution of ______________ _____________________________________________________. The present day distribution of mammals is related to _______________________ found that support this distribution. Continental drift may also have been a factor in the development of the _____________________________________________________. Modern day similarities may be related to the fact that ____________________________________ _____________________________________________________________________.

Embryology There is similar ____________________________ _________________________________________________________________. Similarities fade as _________________________________. These similarities suggests a ____________________ ____________________ for many animal species.


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Comparative Anatomy

Comparative anatomy is the ______________________________________________ ________________________________________ with regard to homologous organs or parts.

1. Homologous structures: structures that have _______________________ ______________________________, but have been modified for that species’ purpose.

__________________________________________

__________________________________________

__________________________________________

recent common ancestor

Example: Mammals have same bones in their _______________ ________________________________________________________________________________________________________. These forelimbs contain the __________________________________________________ __________________________________. The simplest explanation is a _________________________________________________________________________________________________________________. These forelimbs are referred to as _____________________________ _________________________. Homologous structures are similar structures derived from the decent of a common ancestor.

2. Analogous Structures: _____________ _______________________________________________________________ but development was from different origins and _____________________________ _________________________________ (recently anyways).

Examples: bat wing, bird wing and butterfly wing

3. Vestigial Structures: ______________________

________________________________________________________________________________________________________________________ Some of us can wiggle our ears like horses or cats that move their ears to locate sounds. We still have the muscles to do it but ____________ ______________________________________

Examples: ______________, pelvic bones in whales, male Nipple, wings on emu.


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Origin of Life

A highly debatable topic is the ___________________________________________ _______________________________________________ and cells. The debate is not one for evolutionary biologists but for biochemists. The ________________________ ____________________________________________________________________ ________________ and is not meant to explain how the first cell came about. Experiments such as Stanley Miller's have been done that show that given the conditions of primitive earth organic compounds could form. Further experiments can show that given a high concentration of organic molecules such as that of the ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________.

Once a protocell is formed further development is explainable by biological evolution.

2.1 PRACTICE PART 3 of 3: EVIDENCE OF EVOLUTION

1. Fossil records can tell us that fish precede amphibians, which precede reptiles, which precede both birds and _____________________________. (1 mark)

2. Using the _______________________ dating method helps determine the order of fossils by looking at their position found in strata. (1 mark)

3. The absolute dating method dates fossils by using radioactive

_______________________ to assign an actual date. (1 mark)

4. Mass _____________________________ are times when a large amount of existing species disappear within a short period of time. (1 mark)

5. ____________________________ evidence for evolution refers to the study of

distribution of plants and animals throughout the world. (1 mark)

6. Related forms evolve in one location and then ________________________ out into other regions of the world. (1 mark)

7. ____________________________________ is a hypothesis that states the

continents are not fixed in location, but change over time. (1 mark)

8. _____________________________ similarities among organisms provides evidence used to explain that organisms come from a common ancestor. (1 mark)

http://en.wikipedia.org/wiki/Miller%E2%80%93Urey_experiment


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9. ____________________________________ structures are similar in structure, but not function. (1 mark)

10. The wings of an insect and a bird are _________________________ structures.

(1 mark)

11. Anatomical features that are fully developed in one group of organisms, but are reduced and have no function in other similar groups are called ___________________________________ structures (1 mark)

2.2 NOTES: EVOLUTIONARY THEORISTS

Jean Lamarck

________________________________ (1744-1829) was among the first scientists to recognize that living things changed over time. He also realized that organisms were somehow ____________________________________________________. Lamarck put forth two "laws". First, he suggested that _______________________________ ______________________________________________________________________ ______________________________. The changing needs brings about a changed behavior, and that behavior change ________________________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________ within the lifetime of the organism. Secondly, Lamarck argued that all changes in organisms could be _____________________________. His theory could be summarized as:

1 species may evolve into many

species can __________________________ during their lifetime

these ________________________________________ _____________________________________________

new species evolve over time as they acquire more and more differences.

The problem with Lamarck's theory of evolution was the misconception that _____________________________________________________ ____________________________. Today we know that ___________ ________________________________________ (Lamarck's theories were published about 100 years before Mendel's work in Genetics was accepted and the mechanism of inheritance was understood.) Using the Buff Baby example, here is what Lamarck believed. Would Arnold's baby really look like this?


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Example of Lamarckian Evolution

How the Giraffe got its long neck!!! It stretched, and stretched, and stretched to reach the food in the higher branches making its neck longer. What do you think? Is this REALLY possible? Not only did its neck get longer, but its babies all had long necks too!!!

YOU SHOULD WATCH THE WHO WAS CHARLES DARWIN

VIDEOS BEFORE PROCEEDING ANY FURTHER!

Influences on Darwin Ideas that shaped Darwin's theory of Evolution:

1. ____________________________ (geologist) – the _________________________________________ ____________________. This was important to Darwin's theory as it would have taken billions of years for millions of species to have evolved from a common ancestor.

2. Farmers - Darwin learned that ___________________ _______________________________________________________________

____________________________. Farmers noted the ___________________

________________________________________________________________ _______________________________. For example some cows produced lots of milk while others only produced a little. Farmers could use these variations to their advantage _________________________________________________ to use as breeding stock.

3. Thomas Malthus (economist) - ______________ _____________________________________________________________ which he surmised would eventually result in famine, disease, and death. Darwin realized that this also held true for all other organisms and the end result would be _______________________________________ _______________________________________


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Darwin's Theory of Evolution The Premise - Darwin's Theory of Evolution is the widely held notion that ____________________________________________________________: the birds and the bananas, the fishes and the flowers - all related. Darwin's general theory stresses a purely naturalistic (undirected) "_______________________ _______________________". That is, complex creatures evolve from more simplistic ancestors naturally over time. In a nutshell, as random genetic mutations occur within an organism's genetic code, the __________________________________ _____________________________ because ______________________________ - a process known as "natural selection." These _________________________________ __________________________________________________. Over long periods of time, beneficial mutations accumulate and the result is an entirely different organism (not just a variation of the original, but an entirely different creature; e.g., reptilian ancestor to archeopteryx to birds). Natural Selection - Natural selection is the preservation of a _____________________ __________________________________________________________________________________________________________________________________________. Over the centuries, human breeders have produced dramatic changes in domestic animal populations by selecting individuals to breed. Breeders eliminate undesirable traits gradually over time. Similarly, natural selection eliminates inferior species gradually over time. His theory could be summarized as:

1 species can __________________________________

Individuals have __________________________________________________

__________________________________________________________________________________________________________

Natural selection also known as "_____________________________________" Remember, this doesn't necessarily mean stronger! Rather, it is the trait best suited to the environment that will give the organism a better chance at survival than those organisms without the specific trait. The organism that survives will then be able to pass on its genes to the next generation

YOU SHOULD WATCH THE WHAT IS EVOLUTION VIDEO BEFORE PROCEEDING ANY FURTHER!


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Evidence for Evolution by Natural Selection As you have seen previously the color of the Peppered Moths that survive and are able to pass on their traits to the next generation is based on their ___________________ ________________________________________________. The peppered moth provides a good example of evolution based on natural selection. This is called ________________________________________ (triggered by human modifications of the environment (pollution) there is an increase in the dark moths. In summary, ___________________________________________________________ _____________________________________________________________________. Pollution produced during the industrial revolution covered the white barked trees with black soot. ___________________________________________________________ ________________________, the black moths were selected for when the trees were darkened with soot. The population changed due to the white moths being selected against. Examples like the peppered moth show us that organisms have the ________________________________________________________ so this is a likely reason for the diversity on earth today. Adaptation versus Mutation Adaptation: ____________________________________________________________ _________________________________________________________________________________________________________________. Always advantageous (positive). Mutation: a change in DNA that can cause an _____________________________ __________________________________________________________________________________________________________________. Neither are a conscious effort to change physiology/structure. The mutation in DNA can lead to changes in proteins


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DNA Mutation Pr0tein Mutation Changes in Proteins can result in new traits

What Darwin didn't know…

Although he knew there was variation, Darwin did not understand ________________ ___________________________________________________. He was ________ _________________________________________________________________________________________________________________________. The structure of DNA wasn't established by Watson and Crick for another 80 years. DNA and Evolution Mendel's work in genetics provided the following:

________________________________________________________________

____________________________________________________________________________________________________________________

________________________________________________________, Natural Selection is not.

Natural Selection tests the combination of genes and essentially selects for the most "fit" combination.

Results of Evolutionary Change There are ways that species characteristics may change:

1. __________________________________________________________________________________________________________________________________________________________________________________________ Large scale: __________________ ___________ the creation of the current ________________________ on earth from the first living cells.


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Small scale: responsible for the evolution of humans and apes from a common primate ancestor. When Darwin sailed the Galapagos Island, he observed that the islands contained a larger variety of finches than found in Ecuador. He noticed that ________________ ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________. Different conditions on each island resulted in different selective pressures on the organisms creating a greater amount of diversity. Example: Darwin’s finches were dispersed to a variety of islands around the Galapagos with various food sources. The beaks are different for each type of finch that lives in a different area and eats a different type of food. If you __________________________________________________________ _______________________________________________________________.

Artificial Selection ____________________________________________________________________________________________________________________________ All domestic dogs, Canis familiaris, are the same species. Dogs have been ________________________________________________________________________________________________________________________

Selection is sped up many times beyond what would have occurred in nature.


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2. Convergence - __________ ____________________________________________ ___________________________________________________________________________________________________________________________________. This is not a result of evolution from a common ancestor. ______________________________________________________________________________________________________________________________ Example: Hummingbirds and moths. One is a bird and the other is an insect, but _____________________________________________________________ _______________________________________________________________________________________________________________________________. Unrelated species become physically similar. Just like the dolphins and sharks below.

3. Parallel or Coevolution - coevolution can be defined as ____________________ _________________________________________. The members of a coevolving pair ________________________________________ ____________________________________ so that their __________________________________ ____________________________________________________________________. ___________________________________________________________________________________________________________________________


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The acacia plant shown above provides nectar for the ants inside its hollow thorn. The ants defend the plant from herbivores!

Speciation You should follow and read the link of DEFINITION OF A SPECIES before proceeding any further! Speciation is a ___________________________ _______________________________________. Looking at a tree of life that constitutes a species of fruit fly,_______________________________ _________________________________. At that point ___________________________________ ________________________________________________________________________________________________, where previously there had just been one. But why and how did it happen? The branching points on this fruit fly phylogeny represent long past speciation events. Here is one example to show how speciation might occur:

1. The Scene…

2. Disaster Strikes… 3. The Populations Diverge…

4. So we meet again…

A population of fruit flies cheerfully laying their eggs in the mushy fruit...

A hurricane washes the bananas with the immature fruit flies out to sea. The banana bunch eventually washes up on an island off the coast of the mainland. The fruit flies mature and emerge from their slimy nursery onto the lonely island.

Ecological conditions are slightly different on the island, and the island population evolves under different selective pressures and experiences different random events than the mainland population does. Morphology, food preferences, and courtship displays change over the course of many generations of natural selection.

If ______________ ________________ lasts long enough, when the two populations are reintroduced, they can no longer mate or produce viable offspring due to different courtship behaviors, mating seasons, genetics etc. The lineage has split from one species into two.


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This is a simplified model of speciation where members of the same species become _________________________________________. Because they are geographically isolated the two populations can no longer interbreed (__________________________________). This example gives an idea of some of the processes that might be at work in speciation. Geographic barriers such as _________________ _______________________________________________________________________ may separate sub-populations and prevent them from interbreeding. Once _______________________________________ occurs, natural selection usually increases the differences between the separated populations. As the populations become better adapted to different environments, their separate __________________ _____________________ gradually become more dissimilar. If the populations remain separated for a long time, their gene pools eventually become so different that their reproductive isolation becomes permanent. The result is ___________________________. Speciation as the result of geographic isolation is called __________________________________________________. If a population is separated into two different reproductively isolated groups without geographic isolation, it is called _____________________________________. Following are some examples of sympatric speciation: ____________ _____________ ____________ ____________ ____________ ____________ _____________ ____________ ____________ ____________

http://www.biology-online.org/dictionary/Gene_pool


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Rate of Evolution There are two interpretations about the pace or speed of evolution that are based on the fossil record:

1. Gradualism A traditional view that states __________________ ________________________________________________________________________________ in an organism. Darwinian evolution - not much evidence that this is how it works.

2. Punctuated Equilibrium Model This model states that evolution proceeds with _______________________________________________________________________________________________________________. Speciation occurs during ____________________________ __________________________________. The fossil record seems to indicate that many species existed without change for long periods of time. __________________________________ ____________________________________________________________________________________________. Changes occurred in a few thousand rather than a few million years.

YOU SHOULD WATCH THE HOW EVOLUTION HAPPENS VIDEO AND THE WHY DOES EVOLUTION MATTER NOW VIDEO BEFORE PROCEEDING ANY FURTHER!


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2.2 PRACTICE: EVOLUTIONARY THEORISTS

1. If _________________ isolating mechanisms are present this means that reproduction never is attempted. (1 mark)

2. If _________________ isolating mechanisms are present this means that reproduction can take place, but any offspring that are produced are not fertile. (1 mark)

3. In ________________________ isolation, species at the same location occupy

different habitats. (1 mark)

4. In ____________________________ isolation sperm cannot reach or fertilize the egg. (1 mark)

5. Allopatric speciation occurs after a _________________________ prevents

gene flow between a population that used to belong to a single species. (1 mark)

6. In ________________________ speciation, a population divides into two different reproductively isolated groups without geographical isolation. (1 mark)

7. _________________________ refers to the divergence of a species into many

different species by adaptation to different ways of life. (1 mark)

8. The model of evolution that states that change is slow but steady within a lineage with few transitional links is called ____________________________________. (1 mark)

9. The model of evolution that states that there is a period of equilibrium in which

speciation occurs quickly with few transitional links is called ______________ ________________________________ (1 mark)

CHALLENGE QUESTIONS

1. Why was Charles Lyell's hypothesis important to Darwin's Theory of Evolution? (5 marks)


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2. How might have Gregor Mendel's work contributed to Darwin's Theory of evolution? (5 marks)


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2.3 NOTES: AGENTS OF EVOLUTIONARY CHANGE

Conditions Affecting Evolution

No Evolutionary Change = Hardy Weinberg Principle. The __________________________________suggests that if a population is not evolving the allele frequencies in the population ______________________________. This stable condition was called ___________________ _______________________. Hardy-Weinberg Principle states that: "___________________________________ ____________________________________________________________________________________________________________________________________________________________________________________” Shown mathematically by: Where:

______________________________________________________

______________________________________________________ As stated previously, Hardy-Weinberg Principle = No Evolution. The principle is based on 5 assumptions. ___________________________________ __________________________________________________________________________________________________________________________. The conditions required to maintain genetic equilibrium are:

1. Mutations _________________________________________. 2. Individuals neither leave nor enter the population (________________________

_________________________________). 3. Population is ________________________________________. 4. ___________________________________________________. 5. ________________________________________ does not occur.

http://www.biology-online.org/dictionary/Allele_Frequency


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Breaking the Hardy Weinberg Principle = Evolution Reality is:

1. ________________________________________ (cannot control this). 2. Individuals __________________________________________ the population. 3. Populations ____________________________________. 4. ______________________________________________________________. 5. ______________________________________________________________.

Evolutionary Change occurs when one of the requirements of genetic equilibrium are broken. ______________________________________________________________ ____________________________________________________________________.

_______________________________________________________________________________________________________________:

1. Mutations. 2. Genetic drift. 3. Gene flow or Migration. 4. Non-random mating. 5. Natural selection.

YOU SHOULD WATCH THE HARDY-WEINBERG VIDEO BEFORE PROCEEDING ANY FURTHER!

2.3 PRACTCE PART 1 of 2: AGENTS OF EVOLUTIONARY CHANGE

1. Complete the Hardy-Weinberg Lab as directed in the web notes under the drop-down menu for the Hardy-Weinberg Lab. (5 marks)

Mutations Mutations are changes in the _______________________________________________________________. Mutations DO occur although the rate of mutations in most species is not currently well understood. Remember, we have no control over mutations. We expect that mutations occur at a low rate under normal conditions.


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We know they occur at a higher rate if mutagens are present. ____________________________________________________________________________________________________________________________________________________________ (ex. bigger, stronger, faster, smarter). Genetic Drift

The random change ____________________________ ________________________ due to _______________ ______________. In the small frog population below, death of a couple of brown frogs results in no brown frogs in the next generation. ______________________________________________________________________________________________________________________. Every gene “counts” in small populations. Bottle Neck Effect

Genetic drift can create a __________________________________. Populations that are near extinction because of a natural disaster endure a bottleneck effect. Again, change alone may determine which individuals survive these unfavourable times, which act as a bottleneck, thereby _________________________________________ _________________________________________________________________________________________________________________________________________.

Gene Flow or Migration

Individuals DO Enter and Leave Populations.

Immigration is where __________________________________________.

Emigration is where __________________________________________. _____________________________________________________________________________________________________________________________________________________________________________________________________. Canadians, for example, are free to move around the country to go to school or seek employment opportunities. If they find partners in their new location and have offspring gene flow has occurred.

http://www.biology-online.org/dictionary/Mutagen

http://en.mimi.hu/biology/bottleneck.html


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Non-random Mating Individuals _____________ mate randomly. The result of ______________________ _____________________ is that _________________________________________ __________________________________________ and thus, ___________________ (and more copies of their genes) than others. In animals, individuals ______________ _________________________________________________________________. Mate selection is often influenced by things like ______________________________ ____________________________________________.

Assortative mating may also take place where selection of a mate is based on similar characteristics.

YOU SHOULD WATCH THE HOW DOES EVOLUTION REALLY WORK VIDEO BEFORE PROCEEDING ANY FURTHER!

Natural Selection "the non-random survival of random variants"

-Richard Dawkins Only the _____________________________________________________________ _________________________________________________________________________________________________________________________________________.Those that are less well adapted tend to be eliminated. This is the single most important factor that effects genetic equilibrium and drives evolutionary change. Recall that _______________________________________________________ _______________________________________________________________________________________________________________________the peppered moth for instance. Charles Darwin was the first to explain evolution by natural selection. Many other theorist tried to explain evolution but have been discredited.

The ability to survive is related to the _________________________________. Fitness of the individual is measured by _____________________________________ _________________________________________________________________________________________________. Gene mutation is the ultimate source of variation.

http://www.biology-online.org/dictionary/Assortative_mating


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COMPARING LAMARK'S AND DARWIN'S THEORIES OF EVOLUTION

Lamarck Darwin

Example Example

Summary Summary


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Different Types of Natural Selection Natural selection can take many forms. To make talking about this easier, we will consider the distribution of traits across a population in graphical form. In a graph we can see the normal bell curve of trait distribution. For example, if we were talking about height as a trait, we would see that without any selection pressure on this trait, the heights of individuals in a population would vary, with most individuals being of an average height and fewer being extremely short or extremely tall. However, ________ _________________________________________________________________________________________________________________. 1. Stabilizing Selection = _____________________

_____________________________________________________________________ while individuals at both ends of the _____________________ _____________________________. When selective pressures select ____________________ _______________________________________________________________________. For example, plant height might be acted on by stabilizing selection. A plant that is too short may not be able to compete with other plants for sunlight. However, extremely tall plants may be more susceptible to wind damage. Combined, these two selection pressures select to maintain plants of medium height. The number of plants of medium height will increase while the numbers of short and tall plants will decrease.

2. Directional Selection = ____________________________

___________________________________________________________________________________. Directional selection occurs when a change in the environment favors this extreme phenotype. The result is that the population's trait distribution shifts toward the favorable extreme. In the case of such selection, the mean of the population graph shifts. Using the familiar example of giraffe necks, there was a selection pressure against short necks, since individuals with short necks could not reach as many leaves on which to feed. As a result, the distribution of neck length shifted to favor individuals with long necks.


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3. Disruptive Selection = ______________________________

___________________________________________________

_____________________________________________. This is

rare in nature but suggests why speciation could occur without

population segregation. In disruptive selection, selection

pressures act against individuals in the middle of the trait

distribution. The result is a two-peaked curve in which the two

extremes of the curve create their own smaller curves. For

example, imagine a plant of extremely variable height that is

pollinated by three different pollinators, one that was attracted to

short plants, another that preferred plants of medium height and

a third that visited only the tallest plants. If the pollinator that

preferred plants of medium height disappeared from an area,

medium height plants would be selected against and the

population would tend toward both short and tall, but not medium

height plants.

YOU SHOULD WATCH THE NATURAL SELECTION IN ACTION

VIDEO BEFORE PROCEEDING ANY FURTHER


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2.3 PRACTCE PART 2 of 2: AGENTS OF EVOLUTIONARY CHANGE

Please fill in the blanks with the most appropriate term.

1. A _____________________ is when there are a number of observations and those observations have not yet found to be false. (1 mark)

2. All the members of a species occupying the same area at the same time are called a (an) _________________________. (1 mark)

3. A gene pool is all the various ______________________________ in a population. (1 mark)

4. According to the _____________________________ law, if there are no external pressures on a population, the allele frequencies should come to an ___________________________. (2 marks)

5. Hardy and Weinberg used the binomial expression, ____________________________ to calculate the genotype and allele frequencies of a population. (1 mark)

6. If 16% of an ant colony has a recessive trait, _____________________ exhibit the heterozygous trait. (1 mark)

7. ________________________ can be detected by noting a difference from a Hardy-Weinberg equilibrium of allele frequencies of a gene pool. (1 mark)

8. ________________________refers to changes in allele frequencies of a gene pool due to chance. (1 mark)

9. In the ______________________________, a few members of a population may survive a natural disaster and prevent a majority of the types of genotypes from participating in the next generation, as in cheetahs. (1 mark)

10. __________________________ is the movement of alleles between populations by migration. (1 mark)

11. Inbreeding ____________________ the proportion of heterozygous and increases the proportion of homozygotes and recessive abnormalities. (1 mark)

12. ___________________________ is the process by which populations become adapted to their environment. (1 mark)


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Please click on the Guided Activity Link to complete the following:

Evolution Interactive Activity

13. Click on the "Teaching Material" tab at the top of the page, scroll down and then click on the "Grade 9-12 Teacher's Lounge link", Click on the "Comic Strip: Survival of the Sneakiest" and then click "go to resource." Read through the comic strip about crickets and answer the following questions:

a. When it comes to crickets, what does fitness mean? (1 mark)

b. Is calling good or bad for crickets' fitness? Explain. (2 marks)

c. Give examples of how selection is happening in this story. (2 marks)


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d. How does selection favour:

i. Calling? (1 mark)

ii. Not calling? (1 mark)

14. Click on the "Resource library" at the top of the page and then on "Similarities and differences: Understanding homology and analogy" under interactive investigations. Read through this activity on homologous structure and answer the end question:

a. Do you think that sharks' and dolphins' similarities (body shape, fin, and flippers) are homologies or analogies? Explain why. (3 narks)


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15. Click on the "Teaching Resources" tab at the top of the page and then on the link "Correcting Misconceptions" toward the bottom.

a. Choose and describe one misconception that you have held about evolution after reading the appropriate link. (3 marks)


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UNIT 2 ANSWER KEY 2.1 PRACTICE PART 1 of 3: EVIDENCE OF EVOLUTION Answers not available. 2.1 PRACTICE PART 2 of 3: EVIDENCE OF EVOLUTION Click on the Peppered Moth link and attempt a simulation activity. Use what you learn to answer the following questions: 1. How did pollution affect the peppered moth population in industrial England? (1 mark) Initially the majority of the peppered moth population was light in color but overtime, with increasing pollution, the majority of the population became dark in color. 2. Explain the process that led to these changes in the moth population? (3 marks) As in any population, there was random variation, in particular the peppered moth, ranged from a light to a dark color. Before the industrial revolution most of the tree trunks in England were lighter in color and peppered moths that were likewise light in color enjoyed a selective advantage as they were better camouflaged from predators. Thus, they were more likely to survive and pass on their light colored genetics, leading to a mostly light colored population. However, during the industrial revolution the increased pollution deposited actually stained the tree trunks a darker color. Now the light colored moths were more obvious and preyed upon while the dark colored moths enjoyed the selective advantage of camouflage, survived and passed on their dark colored genetics, leading to a mostly dark colored population. 3. What do you anticipate would happen to a predominantly light colored peppered moth population? If a new form of lichen were to take over the tree bark? This new lichen is neither light nor dark. (3 marks) Any peppered moths that had a random color variation similar to the color of the lichen would have a selective advantage, and would be more likely to survive and reproduce to pass on this colored trait. Therefore, the peppered moth population would eventually become dominated by individuals that were similar in color to that of the lichen.

2.1 PRACTICE PART 3 of 3: EVIDENCE OF EVOLUTION Answers are not provided for fill-in the blank questions. 2.2 PRACTICE: EVOLUTIONARY THEORISTS Answers are not provided for fill-in the blank questions. CHALLENGE QUESTIONS 1. Why was Charles Lyell's hypothesis important to Darwin's Theory of Evolution? (5 marks) Charles Lyell hypothesized that the surface of the Earth (geology) as he saw it in his day was a reflection of a steady accumulation of minute changes over extremely long time spans. This hypothesis was very different from the popular assumption that the Earth was exactly as the Earth had always been, as created by God 6000 years earlier. Lyell's hypothesis had a significant impact on Darwin as he was able to see evidence of such geological change during his journey on the Beagle and as he later applied a similar concept to the life on Earth when he proposed that random variations could accumulate over time to lead to the formation of new species. 2. How might have Gregor Mendel's work contributed to Darwin's Theory of evolution? (5 marks) One of the limitations of Darwin's (1809-1882) Theory of Evolution was its inability to explain the source of the random variations that could lead to the existence of beneficial traits and how these traits were passed on from generation to generation. Indeed, Darwin believed that individuals inherited a blend of traits from their parents, a phenomenon that would essentially erase beneficial traits over time and negate or limit his theory. However, unbeknownst to Darwin, Gregor Mendel's work could have been used to support his own theory. Gregor Mendel (1822-1884) was an Austrian monk who studied inheritance patterns in plants. Mendel's work led him to propose Laws of Inheritance that could explain how beneficial


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traits could be "dominant" and passed on from generation to generation without blending occurring. Had Darwin and the general scientific community been aware of Mendel's work at the time it may have led to a wider and more rapid acceptance of Darwin's Theory. Please note that while the discovery of DNA, genes and mutations did not occur until the mid-20th century (1950's and beyond) it has had a significant impact on the scientific community's overall understanding of evolution with respect to sources of random variation (genetic variation via recombination, random assortment of gametes, mutations) and how these variations are passed on from generation to generation.

2.3 PRACTCE PART 1 of 2: AGENTS OF EVOLUTIONARY CHANGE 1. Answers are not provided here for the lab as they can be checked within the lab itself. 2.3 PRACTCE PART 2 of 2: AGENTS OF EVOLUTIONARY CHANGE 1-12. Answers are not provided for fill-in the blank questions. Evolution Interactive Activity 13. Click on the "Teaching Material" tab at the top of the page, scroll down and then click on the "Grade 9-12 Teacher's Lounge link", Click on the "Comic Strip: Survival of the Sneakiest" and then click "go to resource." Read through the comic strip about crickets and answer the following questions: a. When it comes to crickets, what does fitness mean? (1 mark) Fitness whether referring to crickets, or any other organism, refers to an organism's ability to survive the selective pressures within its environment (such as predators and competitors) to reproduced and pass on its traits. b. Is calling good or bad for crickets' fitness? Explain. (2 marks) Calling can be good or bad for a cricket's fitness depending on the situation. Calling is generally good for fitness as it does attract females, potentially leading to reproduction and the passing on of traits. However, calling can be bad for a cricket's fitness if it attracts a predator, ending its life and chances for reproducing and passing on its traits. c. Give examples of how selection is happening in this story. (2 marks) Female is selecting for caller trait. Predator is selecting against the caller trait. Nature is selecting for sneaky as it allows cricket to find a mate Nature is selecting for strong and speedy as it allows for cricket to escape predator and survive. d. How does selection favor: i. Calling? (1 mark) Calling allows for cricket to find mate, reproduce and pass on the calling trait.

ii. Not calling? (1 mark) Not calling allows for cricket to avoid predator, survive and potentially reproduce and pass on the non-calling trait. 12. Click on the "Resource library" at the top of the page and then on "Similarities and differences: Understanding homology and analogy" under interactive investigations. Read through this activity on homologous structure and answer the end question: a. Do you think that sharks' and dolphins' similarities (body shape, fin, and flippers) are homologies or analogies? Explain why. (3 narks) Analogous, do not share a recent common ancestor, evolved due to common selective pressures (living/swimming in water). 13. Click on the "Teaching Resources" tab at the top of the page and then on the link "Correcting Misconceptions" toward the bottom.


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a. Choose and describe one misconception that you have held about evolution after reading the appropriate link. (3 marks)

Answers may vary.

~ END OF BIOLOGY 11 UNIT 2 LEARNING GUIDE ~

unit 2 ~ learning guide name:bclearningnetwork.com/lor/media/bi11/learning_guides/bi11_lg_u… ·...

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