| A | B |
|---|
| mutation | abrupt alteration in genetic information |
| reproductive isolation | separation of different species that can not interbreed |
| gene pool | all the alleles of all the genes of the members of a population that interbreed |
| genetic drift | random change in allele frequency, often producing offspring that will be different from the original population by chance |
| speciation | formation of a new speicies brought about by genetic changes that prevent breeding between new, genetically different groups |
| gradualism | theory that evolutionary change occurs slowly and steadily over long periods of time |
| punctuated equilibrium | pattern of long periods of stability that are interrupted by episodes of rapid change |
| gene shuffling | when the same genes are combined in different ways due to segregation and independent assortment |
| evolution | any change in the relative frequencies of alleles in a gene pool of a species |
| stabilizing selection | keeps the center of the phenotype curve at the center; evolution does not occur |
| Directional selection | when individuals at one end of the curve have higher fitness than individuals in the middle or at the other end;evolution occurs |
| disruptive selection | when individuals at both ends of the curve have a higher fitness than individuals in the middle; evolution occurs |
