BIO 1130 Lecture Notes - Lecture 10: Cambrian Explosion, Geologic Time Scale, Global Catastrophic Risk

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

The earth is about 4500 million years old, multicellular life arose 500 million years ago. Geological time scale: cenozoic (65 ma to present time, mesozoic (251-65 ma (dinosaurs! I think: paleozoic (543-251 ma) (at 550 or so, cambrian explosion) Early paleontologists couldn"t accurately measure the periods based on sedimentary rock because of lack of technology. Modern paleontology; radioactive decay, gives much accurate estimations. However is still hard to comprehend because of the magnitude of years; billions. Cambrian explosion (550 ma): diversification of animal life in oceans; feeding on protists, some life move onto land, than global catastrophe kills off 90% of marine life. Big band causes massive nebula of gases and dust to disperse: centre reaches critical mass creating nuclear explosion igniting our sun to continue to burn even today. Our sun, out of control nuclear explosion, nuclear fusion with hydrogen, resulting energy spread throughout the galaxy.