 | Term | Definition |
| |
Population Genetics |
the study of evolution from a genetic point of view |
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Bell Curve |
a graph of the frequency of a certain trait in a population |
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Gene pool |
describes the total genetic information available in a population |
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Allele Frequency |
this is determined by dividing the number of a certain allele by the total number of alleles of all types in the population |
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Phenotypic Frequency |
this is equal to the number of individuals with a particular phenotype divided by the total number of individuals in the population |
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Hardy-Weinberg Equilibrium |
allele frequencies in a population tend to remain the same from generation to generation unless acted on by outside influences |
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Immigration |
the movement of individuals into of a population |
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Emigration |
the movement of individuals out of a population |
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Gene Flow |
the process of genes moving from one population to another |
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Genetic Drift |
the phenomenon by which allele frequencies in a population change as a result of random events, or chance |
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Assortative Mating |
the selection of a mate based on similarity of characteristics |
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Stabilizing Selection |
in this type of selection, individuals with the average form of a trait have the highest fitness |
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Directional Selection |
in this type of selection, individuals that display a more extreme form of a trait have greater fitness than individuals with an average form of the trait |
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Disruptive Selection |
in this type of selection, individuals with either extreme variation of a trait have greater fitness than individuals with the average form of the trait |
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Sexual Selection |
in this type of selection, females tend to choose the males they mate with based on certain traits |
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Speciation |
the process of species formation; results in many related populations of organisms |
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Morphology |
the internal and external structure and appearance of an organism |
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Biological Species Concept |
this states that a species is a population of organisms that can successfully interbreed but cannot breed with other groups |
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Geographic Isolation |
the physical separation of members of a population |
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Reproductive Isolation |
this results from barriers to successful breeding between population groups in the same area |
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Prezygotic Isolation |
a barrier to successful breeding that occurs before fertilization, such as differences in mating time or behavior |
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Postzygotic Isolation |
a barrier to successful breeding that occurs after fertilization, such as the production of nonviable or sterile offspring |
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Punctuated Equilibrium |
a theory that speciation occurs during brief periods of rapid genetic change |
