unit 7 set 2

Flashcards on Population Evolution

Evolution

Change in the genetic makeup of a population over time.

Competition for resources

The result of overproduction of offspring.

Heritable variations

Variations that exist within a population and can be passed down.

Differential reproductive success

Variations in reproductive success can lead to…

Mutations

The source of new genes and new alleles.

Point mutations

Changes in one nucleotide base in a gene.

Chromosomal mutations

Delete, disrupt, duplicate, or rearrange many loci at once and are usually harmful.

Three mechanisms for sexual recombination

Crossing over, independent assortment, and fertilization

Population

A group of individuals of the same species that live in the same area and interbreed.

Population genetics

The study of how populations change genetically over time.

Gene pool

All of the alleles at all loci in all the members of a population.

Fixed allele

When all members of a population are homozygous for the same allele.

Five conditions for Hardy-Weinberg Equilibrium

No change in allelic frequency due to mutation, random mating, no natural selection, extremely large population size, and no migration.

Hardy-Weinberg equation

Used to describe a population that is not evolving; the frequencies of alleles and genes in a population's gene pool will remain constant over the course of generations.