GEL 107 (8) - GEL107 PALEOBIOLOGY Death is a black camel...

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1 GEL107: PALEOBIOLOGY Lecture 9: Extinction & Origination “Death is a black camel that lies down at every door. Sooner or later you must ride the camel.” - Arabian proverb "Death is the only inescapable, unavoidable, sure thing. We are sentenced to die the day we're born." -Gary Mark Gilmore Some observations. .. • Over geologic time, extinction is the norm! – >99% of Earth’s biota is extinct – Most species persist a few million years and then become extinct – Regardless of standing diversity, species- level turnover is high Extinction has made a significant impact on the pattern of evolution. Over geologic time, extinction is the norm! Most species persist a few million years and then become extinct. Regardless of standing diversity, species-level turnover is high
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2 How do we identify extinctions in the fossil record? What are local and global extinctions? What are different types of extinction selectivity? What is species selection? What are background and mass extinctions? Macroevolution Diversity = Origination - Extinction Three sources of macroevolutionary trends 1. Phylogenetic drift. 2. Directed speciation. 3. Species selection Comparable to natural selection in populations.
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This note was uploaded on 12/13/2009 for the course GEL GEL 107 taught by Professor Jishin during the Spring '09 term at UC Davis.

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GEL 107 (8) - GEL107 PALEOBIOLOGY Death is a black camel...

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