BIOL 1111 Chapter Notes - Chapter 24: Ecological Niche, Allopatric Speciation, Hybrid Zone
4 Mar 2016
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Document Summary
Occurs when populations of same species become genetically isolated. Use different habitats or resources within the same area. Species = evolutionarily independant population or group of populations. Populations = different species if reproductively isolated: Either do not interbreed or do not produce viable offspring when they do. No ability to evaluate fossils or distantgeography. What about asexual organisms - prokaryotes, etc. Gene flow between different species does happen. Postzygotic: different species do mate, but offspring have low fitness/do not survive/do not produce own offspring. Impede mating or prevent fertilization if mating does occur. Result in fetal death and/or infertile offspring. Species identified on the basis of morphological differences. Based on reconstructing evolutionary history of populations. Common ancestor + all of its descendants. Species identified as smallest monophyletic group on tree. Could lead to recognition of many more species than other species concepts. Lots of other species concepts have been proposed by different researchers. Not distinct enough to be separate species.
