sexual selection
selection for traits that improve mating success
intrasexual selection
selection within a sex
male competition for the right to mate with a female
intersexual selection
mate choice
females choose the male they want to mate with
sexual dimorphism
difference in appearance of males and females
males look better so females will mate with them
quantitative character
characters that vary along a continuum
discrete character
come in 2 forms
not helpful for natural selection
mutation
random changes in dna
affect mostly populations with with short generational spans (ex. bacteria)
sexual recombination
sex shuffles alleles and deals them at random to offspring
diploidy
two copies of each gene, one inherited from each parent (AA, Aa, aa)
hides genetic variation in the form of recessive alleles that can skip a generation
heterozygotes
one recessive and one dominant gene (Aa)
balanced polymorphism
gives heterozygotes an advantage
how natural selection maintains diversity