Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Unit 7 Evolution
| Term | Definition |
|---|---|
| natural selection | process of evolution developed by Darwin, based on four ideas: overproduction, variation, competition & environmental changes. It explains how traits of a population can change over time |
| evolution | changes in a species population over time |
| homologous structure | similar structures INHERITED from a common ancestor (ex. birds wings, reptile limbs); however these structures have different functions |
| vestigial structure | structure that was once needed but no longer is as important (ex. human appendix or leg bones in whales) |
| analogous structure | structure that has the same function but different structure and was NOT inherited from a common ancestor |
| embryology | the study of organism's early prebirth stages of development |
| fossil record | provides a record of species, shows similar characteristics between living and extinct |
| adaptation | trait that increases an organisms survivability |
| mutation | random changes in the genes of organisms that create new alleles, thereby creating new phenotypes; these phenotypes may or may not be successful in the environment |
| survival of the fittest | the process by which individuals that are BETTER suited to their environment survive and reproduce most successfully; often used interchangeably with the term 'natural selection'; better stated as "survival of the fit enough" |
| genetic variation | the variety of different types of genes in a species or population |
| competition | the struggle between organisms to survive in a habitat with limited resources |
| environmental changes | change in environment that can affect an organism's ability to survive |
| overproduction | organisms produce more offspring than can survive |
| Charles Darwin | English natural scientist who formulated a theory of evolution by natural selection (1809-1882) |
| phylogenetic tree | a branching diagram showing evolutionary relationships of organisms with a common ancestor; considered a hypothesis |
| geographic isolation | isolation between populations due to physical barriers |
| disruptive selection | natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle of the curve |
| directional selection | Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals. |
| stabilizing selection | form of natural selection by which the center of the curve remains in its current position; occurs when individuals near the center of a distribution curve have higher fitness than individuals at either end |
| relative dating | Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock |
| common ancestor | The shared ancestor of new, different species that arose from one population |
| speciation | the formation of new and distinct species in the course of evolution. |
| fitness | measure of the ability to survive and produce more offspring relative to other members of the population |
| extinction | A term that typically describes a species that no longer has any known living individuals. |
| artificial selection (selective breeding) | selective breeding of plants and animals to promote the occurrence of desirable traits in offspring |
Created by:
user-1823163
Popular Biology sets