AP Bio Micro/Macro Evolution

microevolution

change in allele frequencies(characteristics or traits) in a population

variation

evolution can not happen without... \_______(two main types: mutations and sexual reproduction)

genetic drift

a change in the gene pool due to random chance

founder effect

a few individuals become isolated and establish a new population

bottleneck effect

when a large portion of the population is wiped out by a natural disaster or event

gene flow

individuals going into and out of a population of to immigration and emigration

natural selection

only mechanism that produces individuals that are better suited to their environment; increases alleles that provide reproductive advantage

Hardy Weinberg principle of equilibrium

used to describe a population that is not evolving

macroevolution

evolution above the species level; emergence of new species and extinction of others

speciation

process by which one species splits into 2 or more species; occurs due to microevolution and reproductive isolation

species

a group of individuals that can reproduce fertile offspring

reproductive isolation

biological factors that prevent individuals from different species from interbreeding and producing fertile offspring

hybrid

offspring of two individuals from different species

pre zygotic barriers

barriers that occur before fertilization

post zygotic barriers

barriers that occur after fertilization

hybrid zones

a region where two species can meet and mate; an overlap of habitat area \= gene flow

punctuated equilibrium

long periods of stability with short bursts of speciation

gradualism

speciation through many small changes over time