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20 Cards in this Set
- Front
- Back
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Gene pool |
All the genes, including all the different alleles for each gene, that are present in a population at any one time |
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Allele frequency |
Number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene |
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Single-gene trait |
Trait controlled by one gene that has two alleles |
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Polygenic trait |
Trait controlled by two or more genes |
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Directional selection |
Form of natural selection in which individual's at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve |
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Stabilizing direction |
Form of natural selection in which individual's near the center of a distribution curve have higher fitness than individuals at either end of the curve |
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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 |
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Genetic drift |
Random change in allele frequency caused by a series of chance occurrences that cause an allele to become more or less common in a population |
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Bottleneck effect |
A change in allele frequency following a dramatic reduction in the size of a population |
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Founder effect |
Change in allele frequencies as a result of the migration of a small subgroup of a population |
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Genetic equilibrium |
Situation in which allele frequencies in a population remain the same |
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Hardy-Weinberg principle |
Principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change |
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Sexual selection |
When individual's select mates based on heritable traits |
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Species |
A group of similar organisms that can breed and produce fertile offspring |
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Speciation |
Formation of a new species |
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Reproductive isolation |
Seperation of a species or population so that they no longer interbreed and evolve into two seperate species |
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Behavioral isolation |
Form of reproductive isolation in which two populations develop differences in courtship rituals or other behaviors that prevent them from breeding |
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Geographic isolation |
Form of reproductive isolation in which two populations are seperated by geographic barriers such as rivers, mountains, or bodies of water, leading to the formation of two seperate subspecies |
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Temporal isolation |
Form of reproductive isolation in which two or more species reproduces at different times |
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Molecular clock |
Method used by researchers that uses mutation rates in DNA to estimate the length of time that two species have been evolving independently |
