BI SC 002 Lecture Notes - Lecture 36: Selective Breeding, Evolutionary Pressure, Sexual Selection
14 Nov 2016
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Document Summary
Small group branches off to establish a settlement that is: new. Allele diversity is limited to only those present in these individuals. Some traits will become increasingly common: others with disappear. Occurs when population number drastically declines: eliminates many alleles present in original population. Choosing mates based on factors such as: location, physical traits, etc. Truly random shuffling of alleles is not possible: alleles become locally concentrated, examples: Selective pressure: male birds of paradise. Movement of individuals into or out of a population. Alleles come and go with the migrating population gene flow . Can counteract the effects of both: natural selection, genetic drift. Extinctions are an important part of earth"s history. Earth has a 4. 6 million year history. Speciation and extinction have been an important part of evolution since life began. Most of the species that have ever lived are now extinct. Over time, the type and diversity of organisms have changed: new species appear.
