5 causes of microevolution

migration of animals

causes genetic mixing across regions reduce differences between populations

mutation changes DNA sequence

changes amino acid sequence (especially in third base) changes protein? changes structure? changes function? changes in protein may change phenotype and therefore change fitness

natural selection

differential survival and reproduction due to changing environmental conditions

genetic drift

effect of chance events in small populations -founder effect -bottleneck

human evolution today

gene flow in human populations is increasing today transferring alleles between populations

gene flow (migration)

movement of individuals and alleles in and out of populations ex seed and pollen distribution by wind and insect

mutation and variation

mutation causes variation new mutations are constantly appearing

5 causes of microevolution

mutation, gene flow, non-random mating, genetic drift, selection

non random mating

sexual selection

bottleneck effect

when a large population is drastically reduced by a disaster -famine, natural disaster, loss of habitat -resulting population may not accurately represent original gene pool ex. cheetahs all cheetahs share a small number of alleles less than 1% diversity as if all cheetahs are identical twins

founder effect

a new population started by a small group of individuals -rare traits may be at high frequency, common may be missing -skews gene pool of new population -not accurate reflection of original population ex. albino deer Seneca Army Depot

2 bottlenecks

10,000 years ago ice age last 100 years- poaching and loss of habitat