CAS BI 107 Lecture Notes - Lecture 8: Fresca
23 Sep 2015
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Document Summary
Domain, kingdom, phylum, class, order, family, genus, species. Ex) birds are seemingly obviously within the individual aves species, yet they possess qualities that could put them under reptilia. Dna is virtually identical within each region, but between the two regions, there is a 1% difference. Ring species: two populations that are physically close to each other but genetically too distant to breed together. These distant populations are surrounded by other populations that can still interbreed. Ex) greenish warblers: two groups in siberia, east and west. Their speciation was due to gradual change in traits, most specifically the differences in mating songs, even when the two groups physically overlapped territories. Anagenesis: rapid evolution of ancestral form without speciation, leaving no remainder of ancestor species. Cladogenesis: parent species splits into two, forming a clade. Dispersal and colonization / vicariance can isolate populations. Vicariance: when a geographical range is split into separate parts, forming a physical barrier for gene flow and dispersal.
