BIOL 1202 Chapter : Evolution
Document Summary
Homologous-different environmental forces favor changes in structures in related organisms=divergent evolution: common ancestors, ex-same forearm limb of mammals, bats, humans, whales, cats, see picture of limbs. Analogous structures-convergent evolution: similar environmental forces select for similar structures in unrelated organisms, do not share common ancestors. Vestigial structures- evolutionary baggage: rudimentary form of an organ more fully formed in ancestor, whale-mammal that went back t aquatic environment, lost function of back limbs (very small, homan vestigialstructures- aappendix, body hair. 2/1/12: developmental biology, as cells divide, the basic plan for building the body is the same as it was when it first started, most embryos are the same, same sets of genes are turned on. Both seeds are available in this environment: bell curve splits in half, makes 2 separate bell curves, natural selection selected against those in the middle, disrupts original bell curve.
