Humans and the North American Pleistocene Megafaunal Extinction

Presenter: Kelsey Stilson

The Pliestocene Megafaunal Extinction (PME) culled two-thirds of the world’s megafauna (mammal species with an average mass of >44 kg) over the relatively short period of 50,000 to 3,000 years ago. Megafauna are usually the first animals to become extinct in a weakened ecosystem. Human impact and climate change are considered the two main catalysts of the PME. This study looks at this global event from a North American lens, where extant species have been shown to have been genetically altered by the N. American PME and a Bison trans-continental migration has been shown to have a higher correlation with the PME in N. America than human impact or climate change. The ‘overkill’ or ‘blitzkrieg’ model concerning human impact is overturned in favor of a more moderate approach considering the available data. The PME must be thought of on both a local and global scale, where global events greatly increase the likelihood of extinction, but local variation is the ultimate determinate in megafaunal survival, much like the endangered megafauna today.