GOPH 375 Lecture Notes - Permafrost, Deccan Traps, Chicxulub Crater
Document Summary
For organisms to be fossilized: must have dense, robust hard parts (teeth, shells, bones) and rapid burial (not scavenged or disintegrated). Amber fossilization insects caught in tree sap. As glaciers retreat, frozen animals are found with flesh on their bones and food in their stomach. Curvier proved extinction, and recognized that it happened at one time. Hooke proposed the idea of extinction events, and fossils could be used as dating tools. Principle of faunal succession: strata of like age can be recognized by the assemblage of fossils. Law of superposition: younger layers of sediment are deposited on top of older layers they contain. Once geological timescale was created, dates were added using radioactive elements in igneous rock (paleontology) Archaea: relatives of the earliest life forms on earth, killed by oxygen. Earliest organisms lived in the water, only came on land when oxygen formed an ozone to protect land from suns uv rays.
