| A | B |
|---|
| Adaptation | Any trait of an organism that increases its chances of surviving and reproducing |
| DNA | A molecule that contains an organism’s genetic information |
| Evolution | The process by which modern organisms have descended from earlier life forms |
| Fossil | Any remains, trace, or imprint of animal or plant life preserved in Earth’s crust |
| Mutation | A random change in an organism’s DNA; a mutation can have positive, negative, or neutral effects on the organism |
| Natural Selection | The process by which the individuals best adapted to their environment tend to survive and pass their traits to subsequent generations |
| Speciation | The process of one species developing into two or more species that can no longer mate |
| Trace fossil | A rock that preserves evidence such as animal tracks or impressions |
| Traits | The specific way a feature is expressed in an individual organism; for example, blue and green eyes are traits for eye color |
| Variation | The range of expression of a trait within a population |
| Population | All the individuals of one kind in a specified area at one time |
| Species | A group of organisms that can interbreed or pass on its genes to following generations |
| Tetrapod | A vertebrate with four limbs |
