BIOL 2301 Lecture Notes - Lecture 33: Genetic Distance, Stegosaurus, Mitochondrion
15 Sep 2016
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Mix alleles with other to make combination of alleles that determine fitness of organisms. The origin of life and the history of evolution. Evolution doesn"t tell us the origin of life because evolution comes from replications. Want to identify which are more related. Any two lines that intersect indicates there"s a common ancestor. When their last common ancestor was indicates how related they are. Four species across top, lines go down to common ancestors. Any subset is a clade: has at least two endpoints. Root: technically, we can"t really make a root, we have nothing to compare it to. Family tree of butterflies population phylogeny: separate from different species. Species: can"t mate to each other (genetically different enough) Have evidence that life has only arose once. Main difference: nodes on ends of left: a speciation event in which population split, then became extinct, left trying to represent every single organism in species. Causes: habitat barrier, mutations, change in environment.
