3.7.2 and 3.7.3 populations and speciation Flashcards
natural selection
the process which leads to evolution, resulting in species becoming better adapted to the environment
what is a selection pressure
factors which affect the survival of an organism, leading to natural selection
what is differential reproductive success
not all individuals are equally likely to reproduce, resulting in changes to allele frequencies within the gene pool
allele frequency
proportion of an allele in the population
disruptive selection
individuals with either extreme trait are more likely to survive and pass on their alleles, the middle trait becomes less frequent, leading to speciation
what is isolation
the process that results in the creation of a new species
allopatric speciation
two populations being geographically isolated, resulting in the formation of a new species
sympatric speciation
two populations being reproductively isolated whilst in the same location
reproductive isolation
two populations of the same species but they can not breed together, so there is no gene flow
genetic drift
change in allele frequency within a population between generations over generations
what is the hardy weinberg principle
a way to predict the frequencies of alleles in a population
what are the assumptions of the hardy weinberg principle
no migration
no mutation
no selection
random mating
large sample size
what are the 2 equations for hardy weinberg
p+q = 1 (allels)
p² + 2pq + q² = 1 (genotypes)
p= dominant
q= recessive
pq = heterozygous
