| A | B |
|---|
| fossil | remains of a once-living organism |
| extinct | species that is no longer found alive |
| relative dating | a method of determining the age of a fossil by comparing it to other fossils |
| radioactive dating | a method of determining the age of a fossil by measuring the radioactive elements |
| evolution | the process by which species change over time |
| Charles Darwin | a British naturalist who proposed the idea that species change over time |
| mutation | a change in the genetic code |
| variation | differences among individuals of a species |
| natural selection | a theory of "how" evolution occurs--survival of the fittest |
| overproduction | organisms produce more offspring than can survive |
| gradualism | the idea that evolution happens rapidly |
| punctuated equilibrium | the theory that evolution happens suddenly with long period of no change |
| primates | the group of mammals that includes monkeys, apes, gorillas and humans |
| hominids | human-like primates--walk on two feet |
| Homo sapiens | the scientific name for humans |
