Ch 1 - Evolution

Question 1

Evolution definition

Answer 1

change in gene pool gene frequency

Question 2

What process drives evolution?

Answer 2

Natural selection

Question 3

What is natural selection?

Answer 3

population better adapted to gain resources than others

Question 4

What is R in a population size over time graph?

Answer 4

rate of growth

Question 5

What is K in a population size over time graph?

Answer 5

carrying capacity

Question 6

What happens if population size exceeds the carrying capacity?

Answer 6

the population could crash

Question 7

What is the ideal R in a population size over time graph?

Answer 7

sigmoid curve

-grow until just before carrying capacity is reached, then plateau

Question 8

What is the HWP?

Answer 8

Given certain conditions, there’d by a genetic equilibrium that could be maintained indefinitely

Question 9

What is genetic equilibrium?

Answer 9

allelic freq will not change over time

Question 10

What are the conditions required for HWP?

Answer 10

1. Random mating
2. Population must be large enough
3. No migration
4. No mutations
5. No natural selection

Question 11

Why is random mating not feasible?

Answer 11

mating is almost always non-random

-can be assortative or non-assortative

Question 12

What is assortative mating?

Answer 12

individuals choosing mates based on phenotype

Question 13

What is genetic drift?

Answer 13

change in allelic frequency due purely to chance

Question 14

What are the two special cases of genetic drift?

Answer 14

bottleneck effect

founders effect

Question 15

What is the founders effect?

Answer 15

when a smaller populations becomes isolated from a larger population
-The smaller population could be drastically different from the original population

Question 16

What is the bottleneck effect?

Answer 16

when a population shrinks to a much smaller number, then grows
-after shrinking, the survivors may not express all the alleles from before shrinking

Question 17

Why are no mutations not feasible

Answer 17

mutations never stops

Question 18

Why is no natural selection not feasible?

Answer 18

natural selection always occurs

Question 19

Natural selection occurs as long as:

Answer 19

there is variation in population

-genetically based

Question 20

What are qualntitative traits of natural selection?

Answer 20

show incremental variation

-height on a bell curve

Question 21

What are the different types of quantitative selections?

Answer 21

stabilization selection
directional selection
disruptive selection

Question 22

what is stabilization selection?

Answer 22

(a quantitative )

• phenotypic average is formed
• phenotypic extremes selected against

Question 23

What is directional selection?

Answer 23

(a quantitative selection)

-one phenotype extreme is favored over the other extreme

Question 24

What is disruptive selection?

Answer 24

both phenotypic extremes are favored over the average

Question 25

What are the different types of qualitative selections?

Answer 25

show disjunct variations

• manelian traits
• frequency dependent selection

Question 26

What increases variation in populations?

Answer 26

mutations
gene flow
sexual recombination

Question 27

What decreases variation in population?

Answer 27

selection

genetic drift