Presentation on theme: "Gigantism and the Island Rule Tim Schmidt. Questions What caused the extinction of gigantism (Pleistocene megafauna)? What are the causes behind the island."— Presentation transcript:
Questions What caused the extinction of gigantism (Pleistocene megafauna)? What are the causes behind the island rule? Is there a link between the extinction of gigantism in animals and the “island rule”?
Gigantism (Pleistocene megafauna) Mega Fauna = Big animal Pleistocene era ended around 12,000 years ago with recession of last continental glacier Environmental Changes Overhunting journal.davidbyrne.com
Irish Elk http://tembotime.files.wordpress.com/2011/03/irish-elk.gif Known for large antlers Used for fighting (Only in males) Antlers could reach 3.6 m and weigh almost 40 kg Change of environment led to lack of nutrients (Calcium) Could no longer afford antlers energetically Human hunting http://farm3.static.flickr.com/2222/2146772919_f9461a59d8.jpg
Moose vs. Irish Elk (Moen, Pastor, & Cohen, 1999)
Island Rule http://online-show.com/wp-content/uploads/2010/05/tropical_island_screensaver1.jpg Small vertebrates - Gigantism Competitive Release Large vertebrates - Dwarfism Lack of nutrition Increased competition New predators
Conclusion Similarities between Extinction of Megafauna and Island Rule o Both have nutritional constraints o New predator relationships o Increased competition
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