BIOL 1202 Lecture : Bio Notes Jan 28
Document Summary
Animals first evolved in the oceans and then transferred to land. A change in the allele frequency of a population over time. If there is a change in the gene pool, it is considered evolution. Not based on belief system based on experimental results and observations. 53 million years ago pakicetus" (has a skull similar to that of a whale) 48 million years ago fossils show signs of adaptations to aquatic life. 49 million years ago fossils show 3m long mammalian crocodile (amphibious) 40-50 million years ago whale like fossils (semi-aquatic mammal) 38 million years ago durudon (disconnected pelvic bones) 15 million years ago cetotherium (partial skull found: fossil record, comparative anatomy. Homologous structures: different environmental forces favor changes in structures in related organisms = divergent evolution. Similar environmental forces select for similar structures in unrelated organisms.