Topic 13 - Mechanisms of Evolution and Population Genetics

Question 1

Assumptions of Hardy-Weinberg Equilibrium

Answer 1

Absence of: natural selection, genetic drift, gene flow, mutation and non-random mating.

Question 2

Allele frequency

Answer 2

Obtained by dividing the total number of copies of a certain allele by the total number of alleles in that population for a given gene (locus).

Question 2

Gene pool

Answer 2

All the alleles of all the genes in a certain population.

Question 3

p and q

Answer 3

Used to represent the frequencies of two alleles being studied in a population.

Question 4

Hardy-Weinberg equation

Answer 4

Used to describe the genotype frequencies in a population not affected by evolutionary forces. These genotype frequencies can be used as the null hypothesis when testing if a certain locus is evolving.

Question 5

Genetic drift

Answer 5

Random changes in allele frequencies; most important in small populations. Tends to reduce genetic variation via loss of alleles. Random with respect to fitness.

Question 6

Gene flow

Answer 6

Movement of alleles between populations; reduces differences between populations. May increase genetic variation by introducing new alleles; may decrease it by removing alleles. Can be beneficial, neutral or detrimental to fitness.

Question 7

Mutation

Answer 7

Random production of new alleles. Increases genetic variation and can be beneficial, neutral or detrimental to fitness.

Question 8

Non-random mating

Answer 8

Leads to evolution by favouring the alleles of individuals who are able to mate because of proximity or because they have been chosen as mating partners.

Question 9

Populations

Answer 9

The smallest units of evolution

Question 10

Natural Selection

Answer 10

When certain alleles are favoured and increase in frequency, while others are disfavoured and decrease in frequency. Can maintain, increase or reduce genetic variation. Can produce adaptation, increasing fitness.