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16 17 & 18.2

TermDefinition
evolution change over time; the process by which modern organisms have descended from ancient organisms
fossil preserved remains or traces of ancient organsims
artificial selection selective breeding of plants and animals to promote the occurrence of desirable traits in offspring
adaptation heritable characteristics that increases an organism's ability to survive and reproduce in an environment
fitness how well an organism can survive and reproduce in its environment study of past and present distribution of organisms
biogeography study of past and present distribution of organisms
homologous structure similar structures that are shared by related species that have been inherited from a common ancestor
analogous structure body parts that share a common function, but not structure
vestigial structure structure that is inherited from ancestors but has lost much or all of its original function
gene pool all the genes, including all alleles for each gene, that are present in a population
allele frequency number of times that an allele occurs in a gene pool as a percentage of the total occurrence of all alleles for that gene pool
polygenic trait trait controlled by two or more genes
single-gene trait trait controlled by one gene that has two alleles
directional selection form of natural selection in which individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve
stabilizing selection form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve
disruptive selection natural selection in which individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle of the curve
genetic drift random change in allele frequency caused by a series of chance occurrence that cause an allele to become more or less common in a population
bottleneck effect a change in allele frequency following a dramatic reduction in the size of a population
founder effect change in allele frequencies as a result of the migration of a small subgroup of a population
genetic equilibrium situation in which allele frequencies in a population remain the same
Hardy-Weinburg principle principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change
sexual selection type of reproduction in which cells from two parents unite to form the first cell of a new organism
species a groups of similar organisms that can breed and produce fertile offspring
speciation formation of a new species
reproductive isolation separation of a species or population so that they no longer interbreed and evolve into two separate two separate species
behavioral isolation form of reproductive isolation in which two populations develop differences in courtship rituals or other behaviors that prevent them from breeding
geographic isolation forms of reproductive isolation which two populations are separated by geographic barriers such as rivers, mountains, or bodies of water, leading to the formation of two separate subspecies
temporal isolation form of reproductive isolation in which two or more species reproduce at different times
Created by: Sharion Davis