BIOA01H3 Lecture Notes - Lecture 7: Wisdom Tooth, Diatom, Biogeography

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Mark Fitzpatrick

Document Summary

Lecture 7: evidence for evolution - part 2. If life originated on earth in the distant past and then evolved, we should see that the. Rst detectable traces of life on earth should be simple forms and only later would more complex forms appear. The fossil record: occurs when organismal features are preserved long after death, tissues turns to stone, sometimes trace fossils, helped by the lack of oxygen, which decreases decomposition. Fossil record is incomplete - not every single species is represented: soft-bodies were preserved less than hard ones. !1: chances of rare species being nicely fossilized are low, lack of sedimentation - organisms must be covered right away or get too much oxygen, highly dependent on the conditions when the organism died - few were fossilized. Sometimes organisms are preserved in amber; those preserved in ice are preserved better.