20 terms

Bio Vocab Chapter 15

biological species concept
definition of a species as a population or group of populations whose members can breed with one another in nature and produce fertile offspring
major biological changes evident in the fossil record
formation of new species
reproductive isolation
condition in which a reproductive barrier keeps two species from interbreeding
geographic isolation
separation of populations as a result of geographic change or migration to geographically isolated places
adaptive radiation
evolution from a common ancestor of many species adapted to diverse environments
punctuated equilibrium
evolutionary model suggesting species often diverge in spurts of relatively rapid change, followed by long periods of little change
study of multicellular organisms as they develop from fertilized eggs to fully formed organisms
geologic time scale
Earth's history organized into four eras: Precambrian, Paleozoic, Mesozoic, and Cenozoic
radiometric dating
determination of absolute ages of rocks and fossils through calculations based on a radioactive isotope's fixed rate of decay
time it takes for 50 percent of a radioactive isotope sample to decay
continental drift
motion of continents about Earth's surface on plates of crust floating on the hot mantle
mass extinction
episode of great species loss
identification, naming, and classification of species
two-part Latin name of a species
phylogenetic tree
branching diagram, suggesting evolutionary relationships, that classifies species into groups within groups
convergent evolution
process in which unrelated species from similar environments have adaptations that seem very similar
analogous structures
similarities among unrelated species that result from convergent evolution
derived character
homologous characteristic that unites organisms as a group
phylogenetic tree constructed from a series of two-way branch points, suggesting ancestral relationships among species