Term | Definition |
Divergent Evolution | accumulation of differences between two groups until they are a new species |
Convergent Evolution | the independent evolution of similar features in different lineages |
homologous structures | structures in organisms that are similar because of common ancestry, may not share similar function |
vestigial structures | remnants of features that served a function in the organism's ancestors |
analogous structures | share similar function, but not common ancestry |
two ways variation comes | reproduction and mutations |
directional selection | graph shifts in one direction |
stabilizing selection | middle higher fitness |
disruptive selection | left and right |
founder effect | subgroups of original population relocated |
bottleneck | population decrease for at least one generation |
hardy-weinberg conditions | large population; no migration; no mutation; random mating; no natural selection |
gene pool | genes in population |
alele frequency | how common an allele is |
homologous structures | similar structures; common ancestry |
paleontology | fossils shows change in a species over time |
biogeography | similar species are found in similar ecosystems around the world |
morphology | comparing structures (analogous and homologous) |
biochemical of molecular | similarities in gene sequences proteins DNA |
speciation | new species formed |
species | make fertile offspring |
geographic isolation | barriers prevent mating |
ecological isolation | different habitats same region |
temporal isolation | different mating times |
behavioral isolation | different mating rituals |
mechanical isolation | morphological differences |
gamete isolation | sperm and egg don't recognize each other |
hybrid inviability | embryo can't develop |
hybrid sterility/infertility | baby not fertile |
hybrid breakdown | each generation less fertility |
microevolution | changing of allele frequencies in a population over time |
macroevolution | patterns of change over geologic time; determine phylogeny |
gradualism | species are always slowly evolving |
punctuated equilibrium | periods of massive evolution followed by periods with little to no evolution |
adaptive radiation | the diversification of different organisms into different forms filling ecological niches |