BIO120H1 Lecture Notes - Lecture 9: Cichlid, Meiosis, Allopatric Speciation
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BIO120H1 Full Course Notes
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Bio120h1 f - lecture 9 - species, speciation, and hybridization. Mutations that impair flight are not strongly selected against due to lack of predation. Flight can be maladaptive under circumstances with no predators: e. g. blown out to sea and can"t go back (their ancestors were blown to island in the first place), so staying put on the island can be better adapted. Reduced wings allow birds to dive faster and deeper, so they can catch underwater prey easier. Hawaiian honeycreepers all descended from one ancestral species in last 10 million years. Two main concepts, though there are many definitions: Taxonomic (or morphological): based primarily on distinct morphological differences. Biological concept doesn"t apply to all species; e. g. asexual organisms - can see that there is no universal concept, as concept varies among different groups of organisms. Although he formally defined it, dobzhansky had first suggested the definition:
