01:070:111 Study Guide - Midterm Guide: Punctuated Equilibrium, Phylogenetics, Natural Disaster
23 Oct 2017
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Document Summary
99. 9% of species that have existed are extinct. People tend to think that the earth is a safe and benevolent place. Although natural disaster strikes, earth is stable. Changes in the natural world are considered slow and progressive not capable of harming us or our children. If a species died our gradually we still feel earth is safe compared to if a species ended abruptly. 570 mya trilobites were abundant but dwindled out and were extinct 245 mya ago. Bad genes could be seen in susceptibility to disease, lack of sensory perception or inability to reproduce. Bad luck can be seen in a freak catastrophe that eliminated all living things. One could argue that extinction does not exist because species have generally short life. In both scenarios both nature and nurture plays a part spans. However there is no evidence that species have lifespans like individuals have lifespans. Virtual immortality can be seen in certain species (roaches and sharks)
