| A | B |
|---|
| biodiversity | number of different species in an area |
| adaptation | body shape, process, or behavior that helps organism survive |
| natural selection | passing on of traits best suited for survival |
| common ancester | when different species arise from one population |
| fossil | remains of ancient life |
| captive breeding | breeding of endangered species in captivity |
| fossil record | all fossils recovered from the ground |
| geologic time scale | diary for life on Earth |
| mass extinction | large-scale disappearance of many species in a short time |
| species | group of organisms that breed and produce offspring like themselves |
