Population Genetics

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Slide 1

Population Genetics

The study of allele frequencies within a population

Slide 2

Gene Pool

All of the genes of a population of organisms

Organisms that are the most successful at reproducing contribute most to the gene pool

Slide 3

Evolution

Any change in the frequency of any allele within a gene pool

Populations undergo evolution

Individuals do not undergo evolution

Slide 4

Factors Affecting the Allele Frequency

Mutation

Especially important for organisms with short generation times

Slide 5

Factors Affecting the Allele Frequency

Migration

Movement of organisms into or out of the population

Slide 6

Factors Affecting the Allele Frequency

Genetic Drift

Random change in allele frequencies

Occurs mostly in small, isolated populations

Slide 7

Factors Affecting the Allele Frequency

Selection

Environmental pressures

Competition

Climate change

Slide 8

Factors Affecting the Allele Frequency

Nonrandom mating

Preferences in selection of a mating partner

Slide 9

Species

Species: A group of organisms so similar to one another that they can interbreed and produce fertile offspring

Kingdom

Phylum

Class

Order

Family

Genus

Species

Slide 10

Speciation

Speciation is the evolution of new species through time

Speciation occurs most rapidly in a small population

Slide 11

Mechanisms of Speciation

Artificial Speciation

New species have been developed by man

Intentional mutations

Cross breeding

Genetic engineering

Slide 12

Mechanisms of Speciation

Natural Speciation by Isolation of Small Populations

Geographical Isolation

Geographical barriers separate two populations

Mountain ranges

Deep canyons

Bodies of water

Ecological Isolation