NATS 1940 Lecture Notes - Lecture 24: Cambrian Explosion, Cambrian, Phanerozoic
19 Jan 2020
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Document Summary
Eons > eras > periods > epochs > ages. Geologic records are divided into 3 eons. Simple cells with no nucleus or organelles. Complex cells with nucleus and organelles like in animals. The sudden increase in animal diversity during the cambrian period during the. The fossil records records extinctions that have occurred over time where global environmental changes were so rapid and disruptive causing a majority of species to be swept away. The big 5 extinction of the phanerozoic: Diversity has been more or less constant throughout geological time. There has been a steady increase in biodiversity over time. Fossil records support the progressionists view and show an increase in diversity of species throughout the years especially during the cretaceous period where there was a reported spike in biodiversity. But it is also argued that fossil records are biased because fossils are often destroyed. Stress caused by movement of the tectonic plates uplift the plates which eventually erode over time.
