biology 106 exam 2 study guide

biology 106 exam 2 study guide - Three conditions of the...

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Three conditions of the theory of evolution by natural selection: 1. Variation must exist in the population 2. This variation must lead to differences among individuals in lifetime reproductive success 3. Variation among individuals must be genetically transmissible to the next generation Industrial melanism: the phenomenon in which darker individuals come to predominate over lighter ones Homologous structures: structures with different appearances and functions that all derived from the same body part in a common ancestor Vestigial structures: have no apparent function, but resemble structures their ancestors possessed Convergent evolution: parallel evolutionary adaptations in similar environments that tend to favor changes that make two groups more alike Science: the search for patterns in nature and the causes of those patterns Human chromosomes- 46. Monkey chromosomes- 48. The loss of a chromosome must be due to the fusion of two chromosomes. Human chromosome 2 is unique to the human lineage in being the product of a head-to-head fusion of to intermediate-sized ancestral chromosomes. This was discovered because of a telomeric region found in the middle of the second human chromosome. Evolution: the change in allele frequencies in a population Four mechanisms of evolution: 1. Natural selection: increases frequencies of certain alleles 2. Genetic drift: causes allele frequencies to change randomly 3. Gene flow: occurs when individuals migrate into or from populations. Allele frequencies may change when gene flow occurs
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This note was uploaded on 04/07/2011 for the course BIOL 106 taught by Professor Allisonmiller during the Spring '11 term at Saint Louis.

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biology 106 exam 2 study guide - Three conditions of the...

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