exam 3 ppt 9

Question 1

which of the HWE assumptions does not happen in sexual selection?

Answer 1

individuals mating at random

Question 2

how many processes is evolution driven by?

Answer 2

evolution is driven by four processes that change allele frequencies

Question 3

what are the four processes that change allele frequencies that drive evolution?

Answer 3

1) natural selection, 2) genetic drift, 3) gene flow, 4) mutation

Question 4

what is the only adaptive mechanism of evolution?

Answer 4

natural selection

Question 5

only ______ results in adaptations

Answer 5

natural selection

Question 6

definition of adaptation

Answer 6

a feature that has become common in a population by natural selection, because it provides some improved function, leading to increased fitness

Question 7

exps of adaptations

Answer 7

a behavior or anatomical feature that allows escaping predators, a protein or other compound with special physical/chemical properties, an anatomical feature that allows an organism to access resources (bats using echolocation, etc)

Question 8

non-adaptive evolutionary mechanisms (listed)

Answer 8

genetic drift, gene flow, mutation

Question 9

what do genetic drift, gene flow, and mutations cause?

Answer 9

they cause allele frequencies to change, but do not lead to adaptation

Question 10

definition of genetic drift

Answer 10

a change in the frequency of an allele due to the random effects of small population size

Question 11

what is genetic drift with respect to fitness?

Answer 11

it is random with respect to fitness

Question 12

is genetic drift more pronounced in big or small populations?

Answer 12

small

Question 13

what can genetic drift lead to?

Answer 13

it can lead to random loss or fixation of alleles

Question 14

two things that cause genetic drift

Answer 14

founder effect, bottleneck

Question 15

definition of founder effect

Answer 15

when a few individuals leave a population to establish a new population; reproductively isolated (ex: amish populations in US)

Question 16

what alleles will the new population likely have regarding founder effect?

Answer 16

new population is likely to have different allele frequencies than the source population, by chance

Question 17

definition of bottleneck

Answer 17

an extreme example where the population falls to a few surviving individuals; survivors have random traits, no specific reason they survived (ex: cheetahs)

Question 18

what will the alleles be like in a bottleneck population from genetic drift?

Answer 18

bottlenecked population is likely to have different allele frequencies than original population, by chance

Question 19

exp of founder effect in amish populations

Answer 19

amish people had higher frequency of the trait for polydactyly -> resulted in extra fingers/toes being more prevalent in kids now because of reproduction with themselves

Question 20

why is population size important when it comes to genetic drift?

Answer 20

a smaller population= more likely to lose genetic variation more quickly/easier

Question 21

definition of migration

Answer 21

the movement of individuals from one population to another; results in gene flow

Question 22

if individuals that are migrating are producing, what does this lead to?

Answer 22

gene flow (alleles can come and go from populations)

Question 23

exps of migration and gene flow

Answer 23

butterflies

Question 24

consequence of migration/gene flow

Answer 24

populations become more similar -> gene flow “homogenizes” allele frequencies between populations

Question 25

gene flow is ______ alleles

Answer 25

exchanging

Question 26

genetic drift and gene flow measure…

Answer 26

change in allele frequencies

Question 27

where do new alleles come from?

Answer 27

mutation

Question 28

types of mutations

Answer 28

neutral (silent), beneficial or harmful (missense, nonsense, frameshift, etc)

Question 29

types of beneficial or harmful mutations

Answer 29

missense, nonsense, frameshift

Question 30

what is the ultimate source of genetic variation?

Answer 30

mutation

Question 31

no mutation ->

Answer 31

no evolution of any kind

Question 32

mutation alone is usually ____

Answer 32

inconsequential

Question 33

mutation alone is usually inconsequential, but how can it become an important evolutionary process?

Answer 33

combined with natural selection, genetic drift, and gene flow, it becomes an important evolutionary process