Lecture 7 study guide Flashcards
Genetic drift
random fluctuations in allele frequencies
heterozygosity
the frequency of heterozygotes in a population, defined by the formula H=2p(1-p), p is the frequency of one of two alleles
census size
when estimating population size, this is the number of individuals that you count, regardless of whether they’re reproducing or not
effective population size (Ne)
the number of individuals in an ideal population where all individuals reproduce in which the rate of genetic drift would be the same as in the actual population
bottleneck
a sever, temporary reduction in population size
founder effect
genetic drift in a small colonizing population
inbreeding depression
the resulting decline in fitness and fecundity that occurs when closely related individuals reproduce, increases homozygosity in individuals that are more likely to share the same recessive deleterious alleles
inbreeding depression
the resulting decline in fitness and fecundity that occurs when closely related individuals reproduce, increases homozygosity in individuals that are more likely to share the same recessive deleterious alleles
NEUTRAL THEORY OF MOLECULAR EVOLUTION
the great majority of mutations that are fixed are effectively neutral with respect to fitness and are fixed by genetic drift
molecular clock
evolutionary substitutions at the molecular level proceed at a constant rate, so the degree of sequence difference between species can serve as a way to estimate relative divergence times, can be calibrated to estimate actual times using data from the fossil record