ANTH 1001 Chapter : Forces Of Evolution
Document Summary
Change in allele frequencies in a population from one generation to the next. Microevolution (small changes) vs macroevolution (big changes that lead to a new species) Why do they get maintained: sometimes beneficial, neutral, are recessive or hidden. Types of mutations: nondisjunction- too many or too few. Point mutation- one point is swapped for something else, and codes for something completely different: translocation- moved to a different point, deletion and addition- one base pair is removed (frameshift) The proportion of gametes carrying a newly arisen mutation at a given locus. Natural selection and population size determine whether a mutation will increase in frequency in a population. Those with alleles that enable them to survive to reproduce and have fertile offspring. Directional selection: one extreme end of range of variation favored. Stabilizing selection: middle range of variation favored. Disruptive selection: both extreme ends of the variation are favored over the average traits. Anemia caused by mutation in the hemoglobin.
