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18 Cards in this Set
- Front
- Back
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Population |
Group of species that live in the same area at the same time |
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Evolution |
Changes in allele frequency over time |
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Microevolution |
Changes in allele frequency within a population |
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Macroevolution |
Changes in allele frequency that lead to the creation of a new species: speciation |
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Gene Pool |
All the alleles in a population |
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Is the gene pool of a population homozygous or heterozygous? |
- Heterozygotes do indeed exist - Variability in the population allows for adaptation |
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Directional Selection |
A selective force that changes the frequency of an allele in a given direction, either toward fixation or elimination |
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Disruptive / Diversifying Selection |
Simultaneous selection for phenotypic extremes in a population, usually resulting in the production of two phenotypically discontinuous strains |
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Stabilizing Selection |
- Preferential reproduction of individuals with genotypes close to the mean of the population. - A selective elimination of genotypes at both extremes |
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Genetic Drift |
Random variation in allele frequency from generation to generation, most often observed in small populations |
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Founder Effect |
- A form of genetic drift - The establishment of a population by a small number of individuals whose genotypes carry only a fraction of the different alleles present in the parent population |
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Genetic Bottleneck |
- A drastic reduction in population size and consequent loss of genetic diversity, followed by an increase in population size - The rebuilt population has a gene pool with reduced diversity caused by genetic drift |
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Positive Assortive Mating |
Similar genotypes are more likely to mate |
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Negative Assortive Mating |
Dissimilar genotypes are more likely to mate |
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Inbreeding |
- Mating of individuals that are more closely related than any two random individuals - Increases the proportion of homozygotes |
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Coefficient of Inbreeding, F |
- Probability that two alleles of a gene in an individual are identical because they are descended from the same single copy of the allele in an ancestor - F=1: Both allele are derived form the same ancestral copy - F=0: Individuals do not have two alleles derived from some ancestral copy |
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Species |
A group of organisms that maintains a distinctive set of attributes in nature |
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Subspecies |
A morphologically or geographically distinct interbreeding population of a species |
