Mutation and Genetic Drift

Ver más

WORLD´S CITIES

por Paula Alvarez

6 Theories of Population Growth

por Val Lozano

MIGRATION

por Javier Videla

Geog Housing Shortage Causes

por CHEN ZHI XIAN, JOLIE N/A

Mutation and Genetic Drift

Mutation

Ultimate source of genetic variation

Good for environmental changes

95% of mutations are harmful for homozygous genes

1% of mutations are beneficial

4% of mutations are neither harmful or helpful

Age Dependent

Higher rate of mutations in older parents

Random change in an allele

1:1000-1:100000 of offsprings will have a change in allele not from the parent due to mutation

Genetic Drift

Migration

Movement of individuals between established existing populations

Population genes become more alike time goes on and migration is constantly going back and forth between the two

Bottleneck effect

Dramatic reduction in population size leading to reduced genetic variability

Founder Effect

Chance deviation of gene frequency from source population

Larger samples size the smaller the deviation from the average

Random changes in gene frequency from one generation to another

Many either fix the allele or lose it by chance

multiple alleles can't be fixed or lost