| A | B |
|---|
| Radiometric Dating | The estimation of the age of an object by measuring certain radioisotopes. |
| Radioisotopes | Unstable isotopes that break down and give off energy. |
| Half-life | The time it takes for one-half of a given amount of radioisotope to decay. |
| Continental drift | The movement of the earths land masses over geological time. |
| Fossil | Evidence of past life forms, such as imprints. |
| Extinction | The death of all the members of a species. |
| Mass Extinction | An episode during which a large number of species become extinct. |
| Natural Selection | States that individuals that have physical or behavioral traits that make them better able to survive will allow them to suvive and reproduce. |
| Adaptation | A trait that becomes common in a population because the feature provides an advantage. |
| Population | Consists of all the indiviuals of a species in a given area. |
| Reproductive Isolation | Two populations of the same species that do not interbreed because of geological isolation. |
| Gradualism | A slow change over a long period time. |
| Punctuated Equalibrium | A model of evolution in which there are long periods with no change follow by rapid change in a species. |
| Vestigial Structure | A structure found in a species that has no use but does have a use in another species. |
| Homologous Structure | Structures that have common ancestry but may not be use in the same way. |
| Analogous Structure | Structures that do not have a common ancestor but have simular function. |
| Camouflage | Adaptaion that allows an individual to blend in with the suroundings. |
| Mimicry | Structural adaptations that allow one species to resemble another species. |
| Convergent Evolution | Distantly related organisms develope similar traits because they live in simular environments. |
| Divergent Evolution | Evolution in which two simular organisms develope into different forms because they live in different kinds of environments. |
| Evolution | Change over time. |
| Use and Disuse | Hyposthesis that states that an organism can evolve by using or not using a trait. |
| Inheritance of acquired traits | A parent can pass on an acquired trait. It does not happen. |
| Fitness | The ability of an organism to survive and reproduce. |
| Struggle for existence | Members of a population compete for food and living space. |
| Artificial selection | Humans select features of plans or animals that they like or find useful. |
| Survival of the fittest | Organisms that are best adaptated to will survive and reproduce. |
| Overproduction | Organisms reproduce more offspring than can survive. |
| Variation | Difference observed in populations of organisms. |
