assumptions of hardy weinberg equillibrium
no mutation, no gene flow, random matinh, no genetic drift, no natural selectoion
mutations
creates new genetic variation, source of new alleles, rare and random
recombination
does not create new alleles, rearrange existing alleles ito new combinations, increases genotypic diversity not allelic
natural selection
can increase or decrease variation , directional selection- decreases variation, balancing = maintains variation
genetic drift
reduced genetic variation, random loss, fixation of alleles, strongest in small populations
gene flow
increases variation within populations, decreases variation between population, brings in new alleles
mutation selection balance
higher mutations rate increases the equilibirum frequency of deleterious alleles while stronger selection decreases
how man y rounds of random mating restores equibilibrum
one generation of random mating
why is drift stronger in small populations
sampling error is larger when N is small, alleles can be lost or fixed by chance
effect of inbreeding in genotype frequences
increases homozygosity, decreases heterozygosity
allpatric speciation
physical barriar seperates populations, no gene flow, most common
sympatric
speciation withot geographic sepearation but due to bhevaiours
hybrid speciation
new species formed from hybridization
what are limitations of interpreting heritability
heritability tells how much variation is genetic, not how genes work, - onl applies to populations and environment measured.
