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Adv. Bio Ch 23
Term | Definition |
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Genetic Variation | Differences among individuals in the composition of their genes or other DNA segments. |
Mutation | A change in the nucleotide sequence of an organism’s DNA or in the DNA or RNA of a virus. |
Gene Pool | The aggregate of all copies of every type of allele at all loci in every individual in a population. |
Population | A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring. |
Hardy-Weinberg Equilibrium | The state of a population in which frequencies of alleles and genotypes remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work. |
Adaptive Evolution | Evolution that results in a better match between organisms and their environment. |
Genetic Drift | A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next. |
Gene Flow | The transfer of alleles from one population to another, resulting from the movement of fertile individuals or their gametes. |
Directional Selection | Natural selection in which individuals at one end of the phenotypic range survive or reproduce more successfully than do other individuals. |
Disruptive Selection | Natural selection in which individuals on both extremes of a phenotypic range survive or reproduce more successfully than do individuals with intermediate phenotypes. |
Stabilizing Selection | Natural selection in which intermediate phenotypes survive or reproduce more successfully than do extreme phenotypes. |
Sexual Selection | A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates. |