| A | B |
|---|
| mutations | changes in DNA |
| traits controlled by single genes | fewer possible phenotypes |
| traits controlled by several genes | large number of possible phenotypes |
| Fitness (genetic terms) | an organism's success in passing on its genes to the next generation |
| Adaptation (genetic terms) | any genetically controlled trait that increases an individual's ability to pass along copies of its genes |
| Species (genetic terms) | A group of similar-looking organisms that can breed with one another and produce fertile offspring |
| Reproductive Isolation | Members of 2 different species cannot or will no longer interbreed (3 types) |
| Gene pool | Individuals within the same species share a group of alleles |
| Speciation | Formation of a new species |
| Stabilizing selection | organisms near the center of the bell curve are more fit than the one's on the sides of the curve |
| Directional selection | organisms at one end of the bell curve are more fit than the one's in the middle or the other side of the curve |
| Polygenic trait | A trait that is controlled by more than one gene |
| Disruptive selection | organisms at either side of the bell curve are more fit than the one's near the middle of the curve |
| Example of Stabilizing selection | Human birth weight |
| Example of Directional selection | Peppered moths |
| Example of Disruptive selection | Darwin's finches (small and large beaked birds could survive, medium sized beaks did not) |
| Reasons for Speciation | Geographic islolation can lead to different types of reproductive isolation: behavioral isolation, mechanical isolation, and temporal isolation |
| Sexual selection | Some traits aren’t adaptive, but become common due to female preference |
| Handicap hypothesis | If the male can overcome the "bad" trait, he should be more fit |
| Disease resistance | Bright colors on a male can indicate this to female organisms during sexual selection |
| Genetic Drift | The frequency of an allele in a population can increase or decrease due to random chance |
| Evolution (genetic terms) | Any change in the relative frequencies of alleles in the gene pool of a species |
| fossil | The evidence in rock of the presence of a plant or an animal from an earlier geological period (can be the remains or impression of a prehistoric organism preserved). |
| homologous genes/proteins | matching gene sequences (base pairs) which code for the same protein, found in different but related animals - shows common descent. |
| common descent | A group of organisms is said to have this if they have a common ancestor. |
| homologous structure | structures in different animals that may not necessarily perform the same function but they share a similar structure, and therefore a common ancestral origin. For example, the forelimbs of humans and bats are these type of structures. Although they are used differently, the basic skeletal structure is the same and they are derived from the same embryonic origin |
| vestigial structure | an anatomical feature that no longer seems to have a purpose in the current form of an organism of the given species. |
| analogous structure | similarity of function and superficial resemblance of structures that have different origins. For example, the wings of a fly, a moth, and a bird are analogous because they developed independently as adaptations to a common function—flying |
| Jean-Baptiste Lamark | Put forth the idea that idea that acquired characters are inheritable |
| Charles Lyell | A geologist who was largely responsible for the general acceptance of the view that all features of the Earth’s surface are produced by physical, chemical, and biological processes through long periods of geological time. The concept was called uniformitarianism (initially set forth by James Hutton). Lyell’s achievements laid the foundations for evolutionary biology as well as for an understanding of the Earth’s development. |
| Charles Darwin | A naturalist born in England in 1809 who is credited for coming up with the theory of evolution of species. |
| Thomas Malthus | Proposed that humans were born faster than they died, but that certain pressures against overpopulation "controlled" this: famine, war, disease, etc. Darwin saw similar patterns in wildlife populations. |
| Alfred Russel Wallace | Another British naturalist who proposed a similar theory of evolution to Darwin's, during Darwin's time |
| The foundations of Darwin’s Theory | variation in Nature, struggle for existence, natural selection, common descent |
| Evidence for evolution | the fossil record, similar anatomical structures, genetic code/homologous proteins, experiments showing natural selection, and geographic distribution of living species |
| allele frequency | the incidence of a gene variant in a population. |
| bottleneck effect | occur when a population's size is reduced for at least one generation. |
| founder effect | occurs when a new colony is started by a few members of the original population. |
| types of reproductive isolation | behavioral isolation, mechanical isolation, temporal isolation |
| temporal isolation | When two or more species living in close proximity to one another, mate during different times |
| behavioral isolation | Species engage in distinct courtship and mating rituals |
| geographic isolation | The physical separation of members of a population. Populations may be physically separated when their original habitat becomes divided. This can lead to reproductive isolation |
| 3 sources of genetic variation | mutation, genetic recombination during sexual reproduction, and lateral gene transfer |
| lateral gene transfer | the process of swapping genetic material between neighboring bacteria, as opposed to parent to offspring |
| mechanical isolation | a type of reproductive isolation that prevents mating due to physical incompatibilities of either the sex organs or gametes of the organisms |
