Midterm Study Cards Flashcards

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1
Q

Darwin’s theory of evolution by natural selection attempts to explain two big patterns. What are those patterns and what lines of evidence support the process of evolution?

A

-groups that live closer together are more alike
-species are related through common ancestry
Evidence:
Fossils show a record of a change overtime (carbon dating), extinction - prove that things change and evolve, Homologous traits, genetics

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2
Q

What criteria need to be met for natural selection to operate on a population?

A

(Darwin’s 4 postulates)
Variation in the trait, that variation in the trait is heritable, heritable variation is linked to reproductive success

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3
Q

In what ways can natural selection be constrained?

A

fitness trade offs
-selection acts on variation that exists
-plyotophy ?

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4
Q

What can natural selection do that no other evolutionary process can?

A

Only selection that leads to adaptation

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5
Q

What is the Hardy-Weinberg principle and why is it useful?

A

No evolution - it’s a series of assumptions on the conditions where evolution does not occur
Why is it useful?
If an assumption is violated then it tells us that there is evolution occurring

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6
Q

What are you comparing when you apply the Hardy-Weinberg principle? What do you need to calculate to make the necessary comparison?

A

Comparing the genotype frequencies to the observed and expected frequencies

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7
Q

What are the different modes of natural selection and what are their effects on genetic diversity?

A

Disruptive selection - favours the act of the disruption (increase/maintain diversity)
Directional selection- shifts one direction (Increase genetic diversity)
Stabilizing selection - stays in the middle (decrease genetic variation)
Balancing selection - maintains genetic variation for the environment *

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8
Q

Small populations are often at greater risk of extinction. What is one factor discussed in the course that could contribute to this?

A

Inbreeding (reduces genetic diversity, decreases fitness, deleterious recessive alleles (bad allele), increases homozygosity and decreases heterozygosity

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9
Q

Small populations are often at greater risk of extinction. What is one factor discussed in the course that could contribute to this?

A

Inbreeding (reduces genetic diversity, decreases fitness, deleterious recessive alleles (bad allele), increases homozygosity and decreases heterozygosity

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10
Q

Why does sexual selection usually act more strongly on males than females? If you were asked this question as an essay, what would you need to discuss/explain to fully answer the question?

A

Male competition/fitness, males have greater reproductive chance

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11
Q

What are the four species concepts that we covered? What criteria does each concept use to delimit species? What are some advantages and disadvantages of each?

A

Biological species - Group of breeding individuals
Morphological -
Ecological species - function in the environment
Phylogenetic species - homologous traits, monophyletic groups within

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12
Q

Is reproductive isolation essential for the formation of species?

A

Yes, very important

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13
Q

Hardy-Weinberg formula

A

P2+2pq+q2=1

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14
Q

Why doesn’t inbreeding depression, by itself, cause evolution?
a) It decreases the population’s average fitness
b) It limits gene flow
c) It does not change the population’s allele frequencies
d) It increases Homozygosity
e) It violates the Hardy-Weinberg assumptions

A

e) It violates the Hardy-Weinberg assumptions

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15
Q

In seedcracker finches from cameroon, small- and large-billed birds specialize inn cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population?

a) disruptive selection
b) directional selection
c) stabalizing selection
d) no selection would operate because the population is in Hardy-Weinberg equilibrium

A

b) directional selection

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16
Q

Which of the following is most likely to produce an African butterfly species in the wild whose populations show two strikingly different color patterns?
a) artificial selection
b) directional selection
c) stabilizing selection
d) disruptive selection
e) sexual selection

A

d) Disruptive selection

17
Q

Which of the following reproductive barriers would prevent a mating attempt?
a) behavioural isolation
b) hybrid sterility
c) gametic isolation
d) sexual selection

A

a) behavioural isolation

18
Q

Which of the following statements is true?
a) Natural selection is the only mechanism of evolutionary change
b) Individuals evolve, becoming better adapted to their environment
c) The fittest individual is always the one that survives the longest
d) Both survival and reproductive ability contribute to an organism’s fitness.

A

d) Both survival and reproductive ability contribute to an organism’s fitness

19
Q

The following concepts of evolutionary theory are due to random events (i.e., chance) EXCEPT
a) mutation
b) the bottleneck effect
c) natural selection
d) genetic drift

A

b) the bottleneck effect

20
Q

Similar gill pouches in embryos of a chick, human, and cat are an example of _______

A

The inheritance of acquired characters

21
Q

Fill in the blank

A (….) is a big molecule of DNA made up of small repeating units

A

Chromosome