| A | B |
|---|
| adaptation | any trait that helps an organism survive |
| natural selection | the process in which something in a living thing's surroundings determines if it will or will not survive to have offspring |
| mutation | any change in the DNA code |
| species | a group of living things that can breed with others of the same species and form fertile offspring |
| fertile | being able to reproduce by forming egg or sperm cells |
| primates | mammals with eyes that face forward, a well-developed cerebrum, and thumbs that can be used for grasping |
| new-world monkeys | have a tail that grasp like a hand, nostrils open upward |
| old-world monkeys | cannot grasp with tail if they have one, nostrils open downward |
| Homo sapiens | scientific name for humans |
| variation | a trait that makes an individual different from others of its species |
| competition | the struggle among living things to get their needs for life |
| evolution | a change in the hereditary features of a group of organisms over time |
| fossils | remains of one-living things from ages past |
| extinct | a life-form that no longer exists |
| sedimentary rocks | rocks formed from layers of mud, sand, and other fine particles |
| vestigial structure | a body part that no longer has a function |
| embryos | an organism in its earliest stages of growth |
