Biology 1001A Lecture Notes - Lecture 18: Richard Dawkins, Convergent Evolution, Agnatha
4 Apr 2016
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In middle of mass extinction, half species will be extinct by 2100. About 8. 7 million species of eukaryotes (still 9:1 species to discover) Darwin and his ideas: adaptation, evolution and natural selection. Radical idea: all life on earth is descended from a common ancestor. Luca: the last universal common ancestor: branching event, one species that gave rise to all other species, luca had all traits in homologies such as same dna bases, etc. The canterbury tales: converging paths, richard dawkins: the ancestor"s tale. Mrca (most recent common ancestor) exists for many groups of species. Start at present day and climb down the tree of life. 8. 7 million other species doing the same thing. Branching points on tree of life rendezvous points. At each point, meet other species, and the group"s mrca. The number should double each generation: 2 parents, 22 grandparents, 23 great grandparent, by 30 generations, 230 ancestors (>1billion) Similar to how species will have a common ancestor.
