| A | B |
|---|
| species | a group of organisms who members can successfully reproduce among themselves |
| evolution | changes that occur over time |
| natural selection | Darwin's theory of evolution- best adapted survive |
| Darwin | developed a theory of evolution |
| variation | inherited trait that makes an individual different from other members of the same species |
| fossils | remains of life from an earlier time |
| homologous structure | body parts in different species that are similar |
| vestigial structure | body part that is reduced in size and has no obvious use |
| embryology | study of the development of embryos |
| primates | group of animals to which monkeys, apes and humans belong |
| hominids | earliest humanlike primates- walked upright |
| Homo sapiens | our own species |
| Homo habilis | "handy man" |
| extinction | elimination of a species |
| sedimentary rock | type of rock fossils can usually be found in |
| gradualism | slow steady, continuous change of one species into a new species |
| punctuated equilibrium | rapid change of a species caused by mutation of a few genes |
| relative dating | estimating age of fossils based on rock layers |
| radioactive element | an element that gives off radiation |
| endangered species | a species in danger of becoming extinct |
