U09 Evolution Vocabular

4. Ancestor An ancestral group of organisms that is shared by multiple lineage groups; evidence for this includes universal DNA use and similar embryonic developmental stages.
6. Structures Structures not developed from a common ancestor that share a dissimilar developmental pattern. These are results of convergent evolution.
7. Radiation Characterized by multiple species being formed from a single common ancestor as they adapt to different environments.
8. Isolation A cause of speciation where a population is physically separated by geographic barriers, such as a canyon or river, leading to different adaptations over time.
13. Selection The identification by humans of desirable traits in plants and animals, and the steps taken to enhance those traits in future generations.
14. Selection The process by which individuals better adapted to their environment are more likely to survive and reproduce than other members of the same species.
15. Isolation When differences between separated populations prohibit them from breeding with one another.
16. The total disappearance of a species; often caused by environmental changes over millennia.

1. The evolutionary process by which biological populations evolve to become distinct species, often occurring when populations can no longer successfully interbreed.
2. Rock Layers Layers of rock where fossils are found; according to the law of superposition, the oldest layers (and fossils) are at the bottom.
3. Bottleneck A type of genetic drift where a population's genetic diversity is reduced after a significant reduction in size due to a random event like a natural disaster.
4. A diagram used to show evolutionary relationships; the organism at the bottom represents the oldest common ancestor.
5. of the Fittest The process in which organisms better adapted to their environment have a better chance of surviving and reproducing.
9. Structures Structures developed from a common ancestor that share a similar developmental pattern. These are results of divergent evolution.
10. An individual organism's reproductive success in surviving and producing viable offspring.
11. Structure A structure an organism has that is no longer useful but is retained because a common ancestor found it useful (e.g., hip bones in whales or the human appendix).
12. The driving force behind variation that makes evolution possible.
17. Fossils Fossil records (such as those of the horse or whale) that show the most significant overall changes and intermediate forms between ancient ancestors and modern descendants.