BIO 115 Lecture Notes - Lecture 5: Macroevolution
Document Summary
As we move back in time, more and more unfamiliar fossils are found. Lots of things are largely unrecognizable relative to modern forms of arthropods. As we date older rocks, things look weirder and weirder. Organisms in pre-cambrain life, look very different from those on earth today. The history of life on earth involves a long succession of flora and fauna. Not just species but major groups succeed one another through evolutionary time. Ex: in the present, placental mammals, birds, and flowering plants flourish, whole cycads and sea-lilies have diminished. Life on earth has evolved over a period of about 3500my. Fossils tell us that a long succession of flora and fauna has evolved over the course of the history of life on earth. The ice sheets from the last glacial period were in full retreat about 10,000 years ago. Our own species emerged in africa around 100,000 years ago.
