BIO120H1 Lecture 9: Species, Speciation and Hybridization
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BIO120H1 Full Course Notes
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Natural selection, genetic drift, mutation and migration seen as sources of. Microevolution but how can these explain macroevolution (taxonomic diversification) Will microevolutionary forces over the long term give us macroevolution? people didn"t know the answer to this question. Why are there lots of some kind of species but not a lot of others. The species problem there are many ways to define a species. Typically defined by phenotypic similarity (fairly easy to identify within a region - sympatric - but gradual differences across regions - allopatric - more problematic. Phylogenetic species concept : genetic similarity used to identify and define species. Taxonomic (or morphological): based on distinct morphological differences (phenotypic or genetic) Biological: based on inter-fertility (crossability) among individuals. Most evolutionary biologist focus on this concept nowadays. Ernst mayr: a species is a group of interbreeding natural populations that are reproductively isolated from such groups . It is because of reproductive isolation, speciation occurred.
