terms from chapter 23
Terms : Hide Images
| 80597936 | microevolution | change in allele frequencies in a population over generations | |
| 80597938 | average heterozygosity | the average percent of loci that are heterozygous | |
| 80597940 | geographic variation | differences in the genetic composition of separate populations | |
| 80597942 | mutation | a change in nucleotide sequence of an organism's DNA | |
| 80597944 | population | a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring | |
| 80597945 | gene pool | all of the alleles for all the loci in all individuals of the population | |
| 80597947 | Hardy-Weinberg Principle | the frequencies of alleles and genotypes in a population will remain constant from generation to generation | |
| 80597949 | Hardy-Weinberg equilibrium | only Mendelian segregation and recombination of alleles are at work | |
| 80597951 | genetic drift | chance events that cause allele frequencies to fluctuate unpredictably from one generation to the next, especially in small populations | |
| 80597953 | founder effect | a few individuals become isolated from a larger population, this smaller group may establish a new population whose gene pool differs from the source population | |
| 80597955 | bottleneck effect | a sudden change in the environment that drastically reduces the size of a population which causes a severe drop in population size | |
| 80597957 | gene flow | the transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes | |
| 80597959 | relative fitness | the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals | |
| 80597962 | directional selection | conditions favor individuals exhibiting one extreme of a phenotypic range,thereby shifting the frequency curve for the phenotypic character in one direction or the other | |
| 80597963 | disruptive selection | conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes | |
| 80597964 | stabilizing selection | reduces variation and tends to maintain the status quo for a particular phenotype character | |
| 80597965 | sexual selection | a form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates | |
| 80597966 | sexual dimorphism | marked differences between the two sexes in secondary sexual characteristic, which are not directly associated with reproduction or survival | |
| 80597967 | intrasexual selection | selection within the same sex,individuals of one sex compete directly for mates of the opposite sex | |
| 80597968 | intersexual selection | individuals of one sex are choosy in selecting their mates from the other sex | |
| 80597969 | balancing selection | occurs when natural selection maintains two or more forms in a population | |
| 80597970 | heterozygote advantage | individuals who are heterozygous at a particular locus have greater fitness than do both kinds of homozygotes | |
| 80597971 | frequency-dependent selection | the fitness of a phenotype declines if it becomes too common in the population | |
| 80597972 | neutral variation | nucleotide differences in noncoding sequences appear to confer no selective advantage or disadvantage | |
| 80599379 | cline | a graded change in a character along a geographic axis |
