| A | B |
|---|
| Species | a group of organisms that share similar characteristics and can reproduce among themselves to produce fertile offspring |
| Evolution | change in inherited characteristics over time (biological change over time) |
| Natural Selection | organisms with the traits best suited for their environment are more likely to survive and reproduce |
| Variation | a difference in an inherited trait that makes in individual different from other members of its species |
| Adaptation | any variation that makes an organism better suited to its environment |
| Gradualism | a model that describes evolution as a slow, ongoing process by which one species changes into another |
| Punctuated Equilibrium | a model where rapid evolution comes about when the mutation of a few genes results in the appearance of a new species over a relatively short period of time |
| Sedimentary Rock | a rock formed when layers of sand, silt, clay, or mud are compacted and cemented together, or when minerals are deposited from a solution |
| Radioactive Element | a chemical element that gives off a steady amount of radiation as it changes into a non-radioactive element |
| Embryology | the study of embryos and their development |
| Embryo | the earliest growth stage of an organism (prior to birth) |
| Homologous | describes body parts that are similar in origin, structure, or function |
| Vestigial Structure | structures that do not seem to have any function, but may have had some function in an earlier evolutionary predecessor of the organism |
| DNA | Deoxyribonucleic acid - the molecule that controls heredity |
| Radiometric Dating | a way to determine the age of a rock by determining the amount of a certain radioactive element in the rock |
