| A | B |
|---|
| evolution | change in a species over time; process of biological change by which descendants come to differ from their ancestors |
| species | group of organisms so similar to one another that they can breed and produce fertile offspring |
| fossil | trace of an organism from the past |
| catastrophism | theory that states that natural disasters such as floods and volcanic eruptions shaped Earth's landforms and caused extinction of some species |
| gradualism | principle that states that the changes in landforms result from slow changes over a long period of time |
| 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 | inherited trait that is selected for over time because it allow organisms to better survive in their environment |
| artificial selection | process by which humans modify a species by breeding it for certain traits |
| heritability | ability of a trait to be passed from one generation to the next |
| natural selection | mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals |
| population | all of the individuals of a species that live in the same area |
| fitness | measure of an organism's ability to survive and produce offspring relative to other members of a population |
| biogeography | study of the distribution of organisms around the world |
| homologous structure | features that are similar in structure but appear in different organisms and have 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 |
| pseudogene | a DNA sequence that resembles a gene but seems to have no function |
