Lecture 8

Question 1

Gene Flow

Answer 1

movement of genetic variation with migrants from one population to another
-always tends to reduce genetic differences between them

Question 2

Example of Gene Flow

Answer 2

-mitochondrial DNA is only passed on from mother, males don’t pass it on to their offspring

Question 3

Nonrandom Mating

Answer 3

may not be random with respect to any particular gene in question

Question 4

Biased Mating

Answer 4

inbreeding and sexual selection

Question 5

Inbreeding

Answer 5

mating between relatives

-increases frequency of homozygotes

Question 6

Inbreeding Depression

Answer 6

decline in average fitness that takes place when homozygosity increases and heterozygosity decreases in a population

Question 7

Two causes of inbreeding depression

Answer 7

1. many deleterious mutations are recessive

2. at some loci there is an advantage to being heterozygous

Question 8

Inbreeding ________________ allele frequencies, but inbreeding depression _______

Answer 8

does not change

does change

Question 9

Genetic Diversity

Answer 9

natural selection can sometimes increase allelic diversity by influencing allele frequencies

Question 10

Mutation

Answer 10

generates new alleles slowly and randomly

Question 11

Sexual Selection

Answer 11

individuals within a population differ in their ability to attract mates

Question 12

Consequences of Sexual Selection

Answer 12

sexually selected traits often differ sharply between the sexes

Question 13

Sexual dimorphism

Answer 13

refers to any trait that differs between males and females of the same species

Question 14

Sexual Conflict

Answer 14

refers to features that are advantageous in one sex and deleterious in another

Question 15

Benefits of Sexual Selection

Answer 15

• have males compete with eachother ensuring high quality genes
• males help out with rearing offspring giving offspring of sexual species an advantage

Question 16

Usefulness of genetic recombination

Answer 16

• potentially can separate good mutations from bad mutations
• decouple beneficial and deleterious mutations
• can unite multiple advantageous mutations that appeared in different individuals

Question 17

Isogamous species

Answer 17

all individuals produce gametes of same size, no sexual selection is expected because both parents contribute equally to offspring