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Science: 1 sem
Science: Chapter 6 definitions- Evolution
| Term | Meaning |
|---|---|
| species | A group of organisms whose members sucessfully reproduce among themselves. |
| evolution | The changes that occur over time in hereditary features. |
| natural selection | Darwin's theory says that organisims best adapted to their enviromen are more likely to survive and pass their traits to offspring. |
| variation | The occurance of an inherited trait that makes an individual different from other members of the same species. |
| gradualism | A model of evolution, showing a steady , slow, and continious change of one species into new species. |
| punctuated equilibrium | A model of evolution, showing the rapid change of a species caused by the mutation of just a few genes. |
| fossils | The remains of life from an earlier time. |
| sedimentary rock | A type of rock formed when fine particles like mud and sand settle out of water and become cemented together. |
| relative dating | Estimating the age of a fossil by comparing it to younger fossils in the rock layers above and to older fossils in rock layers below. |
| radioactive element | An element that gives off radiation, a form of atomic energy. |
| homologous | Body parts in different species that are similar in origin and structure. |
| vestigial structure | A body part that is reduced in size and has no obvious use. |
| embryology | The study of the development of embryos, which are the earliest stages of an organism's development. |
| primate | The group of mammals to which monkeys, apes, and humans belong and which share several characteristics, such as opposable thumbs. |
| homind | The earliest humanlike primates; ate both meat and veggies and walked upright on two feet. |
| Homo sapiens | Our own species, a homind primate mammal; evolved 300,000 years ago. |
| extinction | The dying out of an entire species. |
| endangered species | A species with so few individuals left that it is in danger of extinction. |