10: population genetics

Question 1

Gene flow (def. + types)

Answer 1

Movement of genes from 1 population to another
- Immigration: a group of individuals moves into a new environment
- Emmigration: a group of individuals leaves their previous environment

Question 1

Types of non-random mating

Answer 1

1) Assortative mating - individuals deliberately mate with those of similar phenotypes
2) Disassortative mating - individuals deliberately mate with those of different phenotypes

Question 2

Genetic drift def. + types

Answer 2

Random events that can alter allele frequency in small populations
1) Bottleneck effect - a random catastrophe (ie, tsunami, fire) indiscriminately kills the majority of a population, leaving only a small sample size left
2) Founder effect - in a population, a small group of individuals is indiscriminately chosen to start a new population elsewhere

Question 3

Disruptive selection

Answer 3

Favors both extremes

Question 4

Directional selection

Answer 4

Shifts allele frequencies one way or another

Question 5

Stabilizing selection

Answer 5

Favors the heterozygote

Question 6

Hardy-Weinberg conditions

Answer 6

1) Large enough population
2) Random mating
3) No mutations
4) No migration
5) No selection

Question 7

3 main mechanisms of evolution

Answer 7

Genetic drift, gene flow, and natural selection

Question 8

Effects of genetic drift

Answer 8

1) Alters allele frequencies drastically in small populations
2) Less genetic diversity
3) Increase the prevalence of harmful alleles (make them fixed (as in constant) in a population)

Question 9

Fitness

Answer 9

How much an individual contributes to the next generation’s gene pool compared to other individuals of that population

Question 10

Intrasexual selection

Answer 10

Members of 1 sex selectively choose their mate of the other sex

Question 11

Intersexual selection

Answer 11

Members of 1 sex (typically female) are selective about their mate (typically male)