BIOL 1001 Lecture Notes - Lecture 16: Western Spotted Skunk, Species Problem, Zygote
23 Mar 2018
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Speciation: starting with the concept of reproductive isolation: origin of species = speciation. Speciation is the process that produces new species from ancestor species. A pro(cid:272)ess, so under most models, species are not created instantly, but over long periods of time. Species can be influx; arrive in large quantities. Current quantities are not fixed genetically; species have variability and natural selection operates all the time. O its diffi(cid:272)ult to dra(cid:449) (cid:271)ou(cid:374)daries arou(cid:374)d (cid:862)spe(cid:272)ies(cid:863) Two patterns to think about: phyletic speciation (anagenesis, phylogenetic speciation (cladogenesis, with generation-by-generation changes, . And if this microevolution occurs in two parts of a gene pool that has split. Then we have speciation: in a y shape, speciation is explained. At the bottom, there are two gene pools, the bottom one likely to be somewhat different from the top one. In the mid-point of the y shape is a point of significant interest in the ph(cid:455)loge(cid:374)(cid:455).
