HARDY-WEINBERG and GENETIC EQUILIBRIUM CH. 16-1 PP 317-320

The Gene Pool Population – group of the same species living in the same area.

The Gene Pool In a population, organisms tend to show small variations of a trait EX: __________________

The Gene Pool In a population, organisms tend to show small variations of a trait EX: __________________ Gene Pool- total genetic information stored in a population

The Gene Pool In a population, organisms tend to show small variations of a trait EX: __________________ Gene Pool- total genetic information stored in a population Allele frequency- Each allele exists at a certain frequency

Variation of Traits in a Population Histogram- graph showing frequencies of each trait. Usually displays a bell curve.

Variation of Traits in a Population Histogram- graph showing frequencies of each trait. Usually displays a bell curve. Bell Curve – shows that most members of a population have a similar variation of a trait. Only a few individuals display extreme variations of the trait. EX: A few fish are very short and a few are very long, most are of average length

WHAT CAUSES THESE VARIATIONS? Mutations- Random change in DNA passed to offspring

WHAT CAUSES THESE VARIATIONS? Mutations- Random change in DNA passed to offspring Recombination- reshuffling of genes during Meiosis Independent assortment crossing over

VARIATION OF TRAITS IN A POPULATION Mutations- Random change in DNA passed to offspring Recombination- reshuffling of genes during Meiosis Independent assortment crossing over Random pairing of gametes

Hardy-Weinberg Genetic Equilibrium Hardy-Weinberg equilibrium describes populations that are not evolving Genotype frequencies stay the same over time as long as certain conditions are met: Very large populations No emigration or immigration No mutations Random mating No natural selection