Biology 1001A Lecture Notes - Assortative Mating, Sympatric Speciation, Theodosius Dobzhansky
4 Sep 2013
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Document Summary
Adaptations to a new food type can cause sympatric speciation (ranges overlap: hawthorn maggot introduced to north america, subset of maggots began feeding only on apples. Competition, disruptive selection & assortative mating sympatric speciation. * stickleback species closely related but do not interbreed. Two types of phylogenies give same types of information. Different branching points represent how closely related particular species are (how long ago the branching point occurred) Time moves bottom to top, left to right (most commonly) Gives information about relative order of branching events. No scale b/c we don"t actually have any indication of time. Splits shown at same time did not necessarily occur at the same time. Some phylogenies give different information ( distance from branching point represents number of changes that have occurred) Be skeptical of people talking about species which are more highly evolved (this is meaningless) Phylogenies are like pedigrees like family trees: building phylogenies.
