| A | B |
|---|
| Microevolution | change in the genetic makup of a population from generation to generation |
| Population Genetics | the study of how populations change genetically over time |
| Modern Synthesis | a comprehensive theory of evolution that integrated ideas from many other fields |
| Population | a localized group of induviduals that are capable of interbreeding and producing fertile offspring |
| Hardy-Weinberg Theorem (HW) | idea that frequency of alleals and genotypes in a population's gene pool remain constant from generation to generation provided that only Mendelian segregation and recombination of alleles are at work |
| Hardy-Weinberg Equilibrium | Idea that frequency of alleles and genotypes will remain constant between generations provided that Mendelian segregation and recombination is at work |
| Conditions for Hardy-Weinberg Equilibrium | 1. large population size 2. no gene flow 3. no mutations 4. random mating 5. no natural selection |
| Mutation | changes in nucleotide sequence of DNA |
| Duplication | an aberration in chromosome structure due to fusion with a fragment of a homologous chromosome, such that a portion of the chromosome is duplicated |
| Genetic Drift | Unpredictable fluctuations in allele frequencies between generations because of a population's finite size |
| Bottleneck Effect | genetic drif from the reduction of a population from a natural disaster, such that the surviving population is no longer genetically representative of the original population |
| Founder Effect | genetic drift when a few induviduals become isolated from a larger population, with the result that the new population's gene pool is not reflective of the original population |
| Gene Flow | genetic additions or subtractions from a population resulting from the movement of fertile individuals of gametes |
| Phenotypic Polymorphsim | phenomenon when two or more distinct morphs are each represented in high enough frequencies to be readily noticeable |
| Genetic Polymorphisim | the existence of two or more distinct alleles at a given locus in a population's gene pool |
| Average Heterozygosity | the average percent of a population's loci that are heterozygous in members of the population |
| Geographic Variation | differences between gene pools of separate populations or population subgroups |
| Cline | a graded change in a trait along a geographic axis |
| Fitness | the contribution and induvidual makes to the gene pool of the next generation, relative to the contributions of other induviduals |
| Relative Fitness | the contribution of a genotype to the next generation compared to the dontributions of alternative genotypes for the same locus |
| Directional Selection | natural selection that favors induvidual at one end of the phenotypic range |
| Disruptive Selection | natural selection that favors individuals on both extremes of a phenotypic range over intermdiate phenotypes |
| Stabalizing Selection | natural selection that favors intermediate variants by acting against extreme phenotypes |
| Balancing Selection | nnatural selection that maintains stable frequencies of two or more phenotypic forms in a population |
| Balanced Polymorphisim | the ability of natural selection to maintain diversity in a population |
| Heterosygote Advantage | greater reproductive success of heterozygous induviduals compared to homozygotes; tends to preserve variation in gene pools |
| Frequency-Dependent Selection | a dedline 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 |
| Neutral Variation | genetic diversity that confers no apparent selective advantage |
| Pseudogenes | a DNA segment very similar to a real gene but which dies not yeild a functional product; a gene that has become inactivated in a particular species because of mutation |
| Sexual Selection | Natural selection for mating sexual success |
| Sexual Dimorphism | a special case of polymorphism based on the distinction between the secondary sex characteristics of males and females |
| Intrasexual Selection | a direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex |
| 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 |
