Term | Definition |
evolution | generally it's the process of change by which new species develop from preexisting species over time; at the genetic level, the process in which inherited characteristics with populations change over time; Darwin defined it "descent with modification |
species | a group of organisms that are closely related and can mate to produce fertile offspring; also the level of classification below genus and above subspecies |
fossil | the trace of remains of an organism that lived long ago, most commonly preserved in sedimentary rock |
catastrophism | theory that states that natural disasters such as floods and volcanic eruptions shaped Earth's landforms and caused extinction of some species |
gradualism | a model of evolution in which gradual change over a long period of time leads to biological diversity |
uniformitarianism | theory that states that the geologic processes that shape Earth are uniform through time |
variation | differences in physical traits of an individual from the group to which it belongs |
adaptation | the process of becoming adapted to an environment; an anatomical, physiological, or behavioral change that improves a population's ability to survive |
artificial selection | the human practice of breeding animals or plants that have certain desired traits |
heritability | ability of a trait to be passed from one generation to the next |
natural selection | the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individual do; a theory to explain the mechanism of evolution |
population | a group of organisms of the same species that live in a specific geological area |
fitness | measure of an organism's ability to survive and produce offspring relative to other members of a population |
biogeography | the study of the geographical distribution of living organisms and fossils on Earth |
homologous structure | body part that is similar in structure on different organisms but performs different functions |
analogous structure | body part that is similar in function as a body part of another organism but is structurally different |
vestigial structure | remnants of an organ or structure that functioned in an earlier ancestor |
paleontology | study of fossils or extinct organisms |