BIO SCI 94 Lecture Notes - Lecture 2: Mns Antigen System, Genotype Frequency, Allele Frequency

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 94
• Professor: Robin Bush

Document Summary

Most scientists don"t use the phrase survival of the fittests to refer to natural selection. Fitness determined by relative proportion of genes an individual contributes to the next generation compared to other individuals. Survival only important in that you only have to live long enough to reproduce. Natural selection only apply to traits that are heritable. Natural selection is acting on a particular gene. One of the other evolutionary mechanisms is at work. In addressing these questions, hardy-weinberg principle functions as the null hypothesis. When genotype frequencies don"t conform to it, evolution/nonrandom mating occurring in population. When alleles are transmitted via meiosis, and gametes combine randomly, allele frequencies do not change. For evolution to occur (allele frequencies to change), some other factor needs to come into play. Four alternative hypotheses to explain the process behind the pattern of changing allele frequencies. Natural selection = only one; all four has different consequences. Genetic drift causes allele frequencies to change randomly.