Term | Definition |
Evolution | The process of change by which new species develop from preexisting species over time; at the genetic level, the process in which inherited characteristics within populations change over time; the process defined by Darwin as "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 or 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 |
Adaption | 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 individuals do; a theory to explain the mechanism of evolution |
Population | a group of organisms of the same species that live in a specific geographical 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 |