BIO152H5 Lecture Notes - Lecture 9: Small Population Size, Allele Frequency, Genetic Drift
Document Summary
Biology is the foundation of medicine and evolution is the foundation of biology. Darwins finches peter and rosemary worked on one island and captured all the birds and measured their beak and body size. In the native balloon tree, the seed is in the middle so those soapberry bug beak is greater than other: conclusion: change in size of food results in selection for matching beak size. Overview of natural selection: environment dictates direction and extent of change. The environment and nature dictates which direction natural selection occurs. Organisms responding to natural conditions and adapting to those conditions: evolution is not predictable. Evolutionary forces can significantly alter the genetic structure of a population: mutation random change in your dna. Increase genetic diversity; creates/adds new alleles into the population. Small population size is affected with the largest affect. Small population size is significantly affected by genetic drift. Chance event- small populations are especially prone to loss of allele through chance.
