Biology Exam Review: Evolution

Front 1

Define evolution

Back 1

The scientific theory that describes changes in species over time and their shared ancestry

Front 2

What is the concept of "survival of the fittest", explain it with an example.

Back 2

The individuals with traits that are more favoured to the environment will survive. Snow shoe hares have white fur in the winter and brown in the summer so they are camouflaged in all seasons.

Front 3

What is a homologous feature? Give an example.

Back 3

A structure with a common evolutionary origin that may serve different functions in modern species.

example: bat wing and human arm

Front 4

What is a vestigial feature? Give an example.

Back 4

A non-functioning structure that is homologous to a fully functioning structure in a closely related species.

example: pigs have 2 toes that don't touch the ground

Front 5

What is an analogous feature? Give an example.

Back 5

A structure that performs the same function as another, but is not similar in origin.

example: bird and insect wings

Front 6

Explain the difference between divergent and convergent evolution. Give an example of each.

Back 6

Divergent: related species become increasingly different due to varied selective pressures

eg. Darwin's finches

Convergent:n two unrelated species become increasingly similar due to similar selective pressures

eg. dolphins and sharks

Front 7

What is a genetic mutation? List the 3 types of genetic mutations, and give an example of each.

Back 7

Changes in the DNA sequence of a chromosome. Beneficial- eg. new and improved protein

Harmful- eg. ineffective proteins

Neutral- eg. neutral protein

Front 8

What is the difference between artificial and natural selection. Give an example of each.

Back 8

Artificial selection: directed breeding; individuals that exhibit a particular trait are chosen as parents eg. dog breeding

Natural selection: nature favours the reproductive success of some individuals within a population eg. snowshoe hares have evolved

Front 9

What is the 100 year experiment? What type of selection does it illustrate?

Back 9

A test on the oil content in corn seeds. It is the longest running experiment in artificial selection.

Illustrates artificial selection.

Front 10

List Darwin's 4 key observations that led to his theory of evolution by natural selection.

Back 10

1. Individuals within a species vary

2. Some of this variability can be inherited

3. Every generation produces more offspring that can survive to pass on their variations

4. Populations of species tend to remain stable in size

Front 11

What 3 inferences did Dawrin make to explain his observations? What was his final conclusion?

Back 11

1. Members of the same species compete with each other for survival

2. Individuals with more favourable variations are more likely to survive and pass them on. Survival is not random.

3. As surviving individuals produce more offspring, favourable variations will become more common.

Final Conclusion: This is natural selection

Front 12

Explain genetic drift and the key factor that influences it.

Back 12

Genetic drift- changes to allele frequency as a result of chance

key factor is the population size (much more pronounced in small populations)

Front 13

List the 4 types of natural selection. Give an example of each.

Back 13

1. Directional selection- hotter chili peppers

2. Stabilizing selection- medium-billed hummingbirds

3. Disruptive selection- longer and shorter billed hummingbirds

4. Sexual selection- female mate choice, male vs male competition

Front 14

What is the bottleneck effect? Give an example of this.

Back 14

Bottleneck effect: loss in genetic diversity following an extreme reduction in population size

example: cheetahs have very little genetic variation because of bottleneck

Front 15

Explain the founder effect using the finches in the Galapagos Islands as an example.

Back 15

A small number of finches established a new population on the Galapagos Islands creating a population with a different mix of alleles.

Front 16

Who were Godfrey Hardy and Wilhelm Weinberg? What principle did they come up with that explains allele frequency in populations?

Back 16

They were mathematicians.

Principle: In large populations where only random chance is at work, allele frequencies are expected to remain constant from generation to generation.

Front 17

Based on the Hardy and Weinberg principle, what 5 conditions result in evolution?

Back 17

1. natural selection

2. small population size

3. mutation

4. immigration or emigration

5. horizontal gene transfer

Front 18

How do Lumarck's, Cuvier's, Lyell's, and Darwin's theories differ?

Back 18

Lumarck: features gain during life can be passed onto kids

Cuvier: patterns of fossils could be accounted for by global catastrophes that wiped out most species on earth

Lyell: geological changes were slow and gradual, natural processes and laws have not changed

Darwin: features born with are passed on

Front 19

List the names given to Lumarck's, Cuvier's, Lyell's, and Darwin's theories

Back 19

Lumarck: theory of inheritance and acquired characteristics

Cuvier: catastrophism

Lyell: uniformitarianism

Darwin: theory of evolution

Front 20

Define cladistics

Back 20

A method of determining evolutionary relationships based on the presence or absence of recently evolved traits.

Front 21

What is a derived trait?

Back 21

A trait that has evolved relatively recently with respect to the species or groups being discussed.

Front 22

Define synapomorphy

Back 22

A derived trait shared by two or more species or groups.

Front 23

What is a cladogram?

Back 23

A diagram that illustrates the evolutionary relationships of different species of organisms.