The Ice Age GIANTS What wiped them out? Angela Via.

The Ice Age GIANTSWhat wiped them out?

Angela Via

What were some of the giants of the Pleistocene?

• Irish Elk• Dire Wolf• Giant Ground Sloth• Giant Ape• American Lion• Giant Beaver

Giant Ground Sloth Smithsonian Museum of Natural History

Large Mammals

• Larger mammals have a pattern of higher incidence of biome specialization

• Typically have lower reproductive rates due to long gestation periods and single births

• Habitats support lower numbers of large animals than small ones

Two Main “Umbrella” Theories

• Climate• Human impact

Climate Change?

• Rapid global climate change-not uniform left “pockets” of suitable environments

• Some species less able to adapt• Rapid change in fauna

Human Colonization?

• Blitzkreig• Mass landscape burning• Disease

Why the debate?

• Model simulations unable to predict accurately all the conditions that could apply

• Dating of when humans colonized certain areas difficult to pick apart

• Too many unknowns about the extinct species

Emerging TheoriesSynergy

Climate suitable areas for Wooly Mammoth Number of kills to drive to extinction

Interesting tid-bits

• Africa is the only land mass that still contains a variety of mega fauna

• Africa is typically believed to be the “birthplace of man”

Future work

• Create a model that can better combine the reduction of the habitats with various effects of humans and differentiate between different scenarios.

References• Bofarull, A. M., A. A. Royo, M. H. Fernandez, E. Ortiz-Jaureguizar, and J. Morales. 2008.

Influence of continental history on the ecological specialization and macroevolutionary processes in the mammalian assemblage of South America: Differences between small and large mammals. Bmc Evolutionary Biology 8:18.

• Brook, B. W., and D. Bowman. 2002. Explaining the Pleistocene megafaunal extinctions: Models, chronologies, and assumptions. Proceedings of the National Academy of Sciences of the United States of America 99:14624-14627.

• Brook, B. W., and D. Bowman. 2004. The uncertain blitzkrieg of Pleistocene megafauna. Journal of Biogeography 31:517-523.

• Burney, D. A., and T. F. Flannery. 2005. Fifty millennia of catastrophic extinctions after human contact. Trends in Ecology & Evolution 20:395-401.

• Gillesie, R. 2008. Updating Martin's global extinction model. Quaternary Science Reviews 27:2522-2529.

• Nogues-Bravo, D., J. Rodiguez, J. Hortal, P. Batra, and M. B. Araujo. 2008. Climate change, humans, and the extinction of the woolly mammoth. Plos Biology 6:685-692.

• Pastor, J., and R. A. Moen. 2004. Palaeontology - Ecology of ice-age extinctions. Nature 431:639-640.

• Yule, J. V., C. X. J. Jensen, A. Joseph, and J. Goode. 2009. The puzzle of North America's Late Pleistocene megafaunal extinction patterns: Test of new explanation yields unexpected results. Ecological Modelling 220:533-544.