Exam 5 objective questions

Question 1

How did Plato’s typological thinking regard phenotypic variation within a species

Answer 1

Unchanging. Perfect essence (phenotype

Question 2

Describe Aristotle’s “Great Chain of Being.”

Answer 2

Ladder – humans on top being as good as species can get

Question 3

How did Lamarck’s ideas on species differ from Aristotle’s and how did Lamarck incorporate inheritance of acquired characteristics

Answer 3

Escalator – less complicated to more complicated

Question 4

How did Wallace and Darwin’s ideas differ from Plato, Aristotle and Lamarck

Answer 4

Came up with natural selection which is the process component of evolution. Evolution of natural populations – changed over time. A variation of traits is important because now there is an adaptive potential

Question 5

Describe the pattern component of the theory of evolution

Answer 5

Species change over time and they have common ancestors

Question 6

In what ways did the fossil record contribute to the pattern component of the theory of evolution (Hint: extinction, transitional features, vestigial traits)

Answer 6

Extinction: Irish Elk example. We wouldn’t have been able to miss that thing if it was still around today!!!
Transitional features: Tetrapod limbs example. If we go back into the fossil record and the older they are, the less and less limbs they have.
Vestigial traits: Human tail bone example. We don’t have tails anymore but we used to.

Question 7

What are some examples of evolutionary changes observed in nature in modern times

Answer 7

Pesticide resistant insects

Bugs developing antibiotic resistance

Question 8

What types of homology can help illustrate descent from a common ancestor

Answer 8

Structural homology
Genetic homology
Developmental homology

Question 9

What does it mean for a theory to have “internal consistency”

Answer 9

Lots of sources of evidence supporting this theory

Question 10

What is the process component of evolution

Answer 10

Natural selection

Natural selection acts on individuals but actually evolves populations. Removes unfit individuals from population

Question 11

What were the two sources of inspiration for Darwin for the process component of evolution

Answer 11

Artificial selections – doves

And Malthus book

Question 12

What are Darwin’s four postulates

Answer 12

• Individuals vary for heritable traits
• These traits are heritable – they can be passed on from one generation to the next
• More offspring are produced than can survive
• Individuals with certain form of that trait are more likely to survive than others within the population

Question 13

Describe the two examples of evolution through natural selection that we discussed in class that have been documented in modern times

Answer 13

• Tuberculosis – individuals vary in traits because some were resistance to the medication and some were not. This resistance can be passed on to offspring. Limited resources with harsh environment. Only individuals resistant to medication can survive
Finches in Galapagos – Individuals vary for beak depth trait. This can be passed on to offspring. Drought makes it so not all offspring produced can survive. Finches with longer beaks survive

Question 14

At what levels do natural selection and evolution occur

Answer 14

Natural selection – individuals; weeds out individuals who are not fit
Evolution – populations; change of allele frequencies

Question 15

What is the difference between acclimatization and adaptation

Answer 15

Acclimation – phenotype changes; response to environment; red blood cell example
Adaptation – genotype changes;

Question 16

Why do we say that evolution is not “goal directed” or “progressive”

Answer 16

Evolution is not goal directed, it’s random. Every once in a while there is a mutation that will be beneficial to the population so natural selection will act on that. Sometimes things will evolve to become more simple, it just depends on the environment they are trying to adapt to. Ex: tapeworms

Question 17

What are some examples of clear constraints to evolution

Answer 17

We have to wait for the right variation of traits to be produced for adaptation to occur.
Traits that evolve are not always best fit for everything

Question 18

What would be an example of a fitness trade-off

Answer 18

• Fewer offspring but increase of change of survival for those offspring

Question 19

If you were told that p = 0.6 and q = 0.4, how would you calculate expected genotype frequencies within a population

Answer 19

• If p = A1 and q = A2, what is the frequency of the homozygote A1? (0.6)^2 = 0.36
• What is the frequency of the A2 homozygotes? (0.4)^2 = 0.16
• Frequency of the heterozygote? 2pq = 2(0.6)(0.4) = 0.48

Question 20

What is the Hardy-Weinberg equation

Answer 20

p+q=1

Question 21

What is inbreeding depression and how is it caused

Answer 21

Inbreeding is breeding of close relatives. Increase in homozygous individuals so there is less variation in future generations, resulting in deleterious alleles being more prominent making the population less fit

Question 22

What are the four evolutionary processes that change allele frequencies

Answer 22

Natural selection
Gene flow
Genetic drift
Mutations

Question 23

Disruptive selection

Answer 23

can result in speciation

Question 24

Balancing selection

Answer 24

ex: babies with average birth weights have a better chance of surviving than babies with low or high birth weights

Question 25

Stabilizing selection

Answer 25

pushing towards middle to one specific version of trait, decreasing diversity

Question 26

Directional selection

Answer 26

pushing population in certain direction

Question 27

What is the difference between intersexual selection vs intrasexual selection

Answer 27

Intersexual: mate choice. Individuals, usually female, are picky choosing their mate. Look for males that would help care for young/provide resources. There are some characteristics (more colorful beaks and feathers, etc.) that can show the females who the healthiest mates would be.
-Intrasexual: competition. Direct competition among individuals of one sex for mates of the opposite sex (usually occurs in males).

Question 28

Describe the pattern and process components of the Bateman and Trivers theory of the Fundamental Asymmetry of Sex

Answer 28

Pattern of colorful bodies and displays by males being favored
Process is the female choosing the right male. Female is choosy because she invests a ton of resources into having offspring

Question 29

What examples have been observed that support the fundamental asymmetry of sex theory

Answer 29

Example where they some finches better diet than others. Ones with better diet had more colorful beaks and were chosen by females

Question 30

What is genetic drift and what is an example of how it could occur

Answer 30

Any change in allele frequencies in a population due to chance

Question 31

How does population size determine the influence of genetic drift

Answer 31

Small population = faster drift