CO SCI 136 Lecture Notes - Lecture 26: Comparative Anatomy, Irish Elk, Georges Cuvier
Document Summary
Organisms evolved from very simple self-replicating molecules without outside intervention. There are numerous explanations for the genesis of biodiversity: Biblical account: creation occurred 6-10 thousand years ago, for six 24-hour days. Hindu account: snake + vishnu + lotus flower, reveals brahma, creates universe and biodiversity. Generally, these explanations are very easy to understand and follow. It is clear that life has changed and evolved a lot since creation. Fossils: the remains, an imprint, or a trace of a prehistoric organism. Most fossils are found in sedimentary rock and occur when an organism is covered in some form of sediment. Trace fossil: e. g. burrows, footprints, borings, feeding marks, root cavities. Imprint fossil: when an organism"s organic material decays away leaving an impression in the sediment it was buried in. Remains fossil: a rarity because most organisms will be consumed or completely decay, e. g. bones.
