Exam Two

Question 1

What is a gene pool?

Answer 1

All the genes in a population

Question 2

What are the conditions for the Hardy-Weinberg Equillibrium?

Answer 2

No natural selection
Random mating
Large population
No mutaion
No migration

Question 3

What is soft selection?

Answer 3

An individual will not have as many offspring

Question 4

What is hard selection?

Answer 4

An individual will not have any offspring

Question 5

What is gene flow?

Answer 5

Flow of genes in and out of gene pool

Question 6

What is the island continent model?

Answer 6

Individuals can move from the island to the continent and not affect the gene pool, however, if an individual moves from the continent to the island the gene pool will be changed

Question 7

What reduces the difference between two populations?

Answer 7

Migration

Question 8

What must be interrupted in order for speciation to occur?

Answer 8

Gene flow

Question 9

What is the founder effect?

Answer 9

A small population will have a distinctly different gene pool from the original genepool

Question 10

What is genetic drift?

Answer 10

Random fluctuation in allele frequencies due to sampling effects in finite populations
Allele frequencies fluctuate over time

Question 11

What is observed heterozygosity?

Answer 11

The fraction of individuals that are heterozygous at a particular locus

Question 12

What is expected heterozygosity?

Answer 12

Fraction of heterozygotes expected under the Hardy-weinberg model

Question 13

How can you tell if heterozygotes are at an advantage in a population?

Answer 13

If observed is greater than expected

Question 14

What is runaway sexual selection?

Answer 14

One trait is desired so females choose that so their sons will reproduce, trait then becomes excessive

Question 15

What is the handicap principle hypothesis?

Answer 15

Elaborate displays would result in the death of the organism if they were not in good condition, therefore those with the best displays are in the best condition

Question 16

What is the parasite load hypothesis?

Answer 16

High parasite loads decrease a males ability and it is represented in a trait

Question 17

What is intersexual selection?

Answer 17

Female chooses the males to mate with

Question 18

What is intrasexual selection?

Answer 18

Males compete for the chance to mate with a female

Leads to size dimorphism

Question 19

What are quantitative traits?

Answer 19

Continuously variable traits
Polygenic
Multifactorial: Enviornmental influences

Question 20

What does it mean to be polygenic?

Answer 20

Trait is influenced by several to many genes

Question 21

What is directional selection?

Answer 21

Organisms at one end of the bell curve are most likely to reproduce

Question 22

What is stabilizing selection?

Answer 22

Organisms in the center of the bell curve are most likely to reproduce

Question 23

What is disruptive selection?

Answer 23

Organisms at both ends of the bell curve are most likely to reproduce

Question 24

What is the neutral theory of molecular evolution?

Answer 24

Most variation present within a population is selectively neutral

Question 25

Who created the idea of neutral theory of molecular evolution?

Answer 25

M Kimura

Question 26

What are pseudogenes?

Answer 26

Nonfunction, untranslated regions of the genome

Question 27

What is genetic equidistance?

Answer 27

If molecular evolution proceeds at the same rate over time, then all members of a clade should be equidistant from an outgroup

Question 28

What is the molecular clock?

Answer 28

If we know the substitution rate then we can determine the distance between two species

Question 29

What is the problem with the molecular clock theory?

Answer 29

Not all loci evolve at the same rate Not all lineages evolve at the same rate\ Saturation

Question 30

What are the four ways that genetic variation can enter a population?

Answer 30

Recombination Mutation Migration Lateral gene transfer

Question 31

What is population genetics?

Answer 31

Studies how the genotype frequencies in an offspring population are related to the parental population

Question 32

What are the three conclusions that the Hardy-Weinberg equilibrium provides?

Answer 32

1. The frequencies of A1 and A2 do not change over time 2. Given allele frequencies, we can predict the equilibrium genotype frequencies 3. If no evolutionary processes are operating, a locus that is not at equilibrium will reach equillibriim

Question 33

What is underdominance

Answer 33

The A1A2 heterozygote has a lower fitness than either A1A2 genotype

Question 34

What is overdominance?

Answer 34

Heterozygote is at an advantage, | Also called heterozygote advantage

Question 35

What is selective neutrality?

Answer 35

There is no fitness difference between the two alleles