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20 Cards in this Set
- Front
- Back
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Phenotypic Polymorphism |
the maintenance of internal body temperature within a tolerable range |
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Genetic Polymorphism |
animals, such as reptiles (other than birds),fish or amphibians, that muse use environmental energy and behavioral adaptations to regulate its body temperature |
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Average Heterozygosity |
an animal, such as a bird or a mammal, that uses metabolic heat to regulate body temperature |
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Geographic Variation |
Differences between the gene pools of separate populations or population subgroups |
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Cline |
A graded variation in a trait that parallels a gradient in the environment |
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Fitness |
The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals |
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Relative Fitness |
The contribution of one genotype to the next generation compared to that of alternative genotypes for the same locus |
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Directional Selection |
Natural selection that favors individuals at one end of the phenotypic range |
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Disruptive Selection |
natural selection that favors individuals on both extremes of a phenotypic range over intermediate phenotypes |
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Stabilizing Selection |
Natural selection that favors intermediate variants by acting against extreme phenotypes |
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Balancing Selection |
Natural selection that maintains stable frequencies of two or more phenotypic forms in a population (balanced polymorphism) |
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Balanced Polymorphism |
The ability of natural selection to maintain diversity in a population
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Heterozygote advantage |
Greater reproductive success of heterozygous individuals compared to homozygotes; individuals compared to homozygotes; tends to preserve variation in gene pool
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Frequency-Dependent Selection |
A decline in the reproductive success of a morph resulting from the morph’s phenotype becoming too common in a population; a cause of balanced polymorphism in populations |
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Neutral Variation |
Genetic diversity that confers no apparent selective advantage
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Pseudogenes |
A DNA segment very similar to a real gene but which does not yield a functional product; a gene that has become inactivated in a particular species because of mutation |
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Sexual Selection |
Natural selection for mating success |
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Sexual Dimorphism |
A special case of polymorphism based on the distinction between the secondary sex characteristics of males and females |
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Intrasexual Selection |
A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex |
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Intersexual Selection |
Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice |
