BIO120H1 Lecture Notes - Lecture 9: Ecological Speciation, Organism, Zygosity
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BIO120H1 Full Course Notes
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Document Summary
Is the evolution of adaptation requires for speciation. Idea of biological species concept is great but not easy to follow through with due to lack of data/info. Concepts vary among different groups of organisms - no universal concept. Splitters --> name many species the second there is phenotypic difference shape colour. Lumpers --> lump together thing with diff phenotypes as one species if can reprodcuce tgoether. Theory of geographic speciation sin geographical isolation is involve. Gene flow is stopped between two population and genetic drift both cause pops to diverge. If migration brings them back together (secondary contact) can no longer reproduce together = two species. Relation between genetic distance and postmating isolation in fruit flies. Genetic distance - measure of the degree of genetic differentiation between samples. More genetically different more likely to produce sterile offspring. Black crow and hooded crow (corvus corone x corvus cornix) Adaptation to freshwater in 3-spined stickleback involves loss of bony defensive armour.
