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Unformatted text preview: ing
the rise and fall
of groups of organisms
1. Adaptive Radiation
2. Continental Drift
3. Mass Extinction 80 Extinction Background extinction:
A few species lost on
an ongoing basis
• > 60% of species
• different lineages go
extinct at approx. same time
Quaternary ~5-6 major extinction
events in Earth’s history 81 Permian Mass Extinction
(~250 Mya) Largest mass extinction event ever:
~95% of living species go extinct!
Associated with very rapid
warming of climate.
• Massive volcanism?
• Frozen CH4 released
(=positive feedback)? 82 Permian Mass Extinction
Extinct: Heavy losses:
Brachiopods Opened up opportunities for surviving organisms:
Adaptive radiation! 83 Cretaceous Mass Extinction
75% - 85% of species lost • Asteroid or comet impact
• No long-term climate shift 84 Cretaceous Mass Extinction
Extinct: Heavy losses: Ammonoids Mosasaurs Photosynthetic organisms
(algae, land plants) Large land animals
(dinosaurs, marsupials) Result:
Adaptive radiation! 85
Adaptive Radiations often
follow major extinctions...
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This note was uploaded on 02/12/2014 for the course BIOLOGY 2011 taught by Professor Woo during the Fall '10 term at University of Central Florida.
- Fall '10