Gene Pools

Gene Pool

Sum of all different alleles present in a population at a specific time

Population

Group of individuals of the same species living together at a specific time

Alleles

Alternative form of the same gene

Allele frequency

How often each allele of a gene occurs in the gene pool
> changes over time = evolution

Evolution

Change in allele frequency in a population overtime

mutations

-          new allele

-          all mechanisms for evolution depend upon mutations occurring

doesn’t have much of an effect without one other mechanism of evolution: genetic drift and natural selection (low mutation rates relative to population growth in most species)

random genetic drift

Random non-directional changes occurring in allele frequency of a population overtime

-          not all individuals can contribute their genes to next generation

-          doesn’t cause adaptations

-          pronounced effect on small interbreeding populations

Ø  lost from gene pool 0%

fixed (100%)

Gene flow

movement of genes into or out of population (immigration and emigration)
- population may gain or lose alleles through gene flow

-reduce differences between population as gene pools become for similar

Barriers to gene flow

physical: lakes oceans mountains

socio cultural: languages religion social position