The Hyper-Disease Hypothesis: Did Humans Bring About Doomsday for the Megafauna of the Pleistocene?

By Erika Lyon

It is a concern that we are entering Earth’s 6th mass extinction.  Mass extinctions occur when a large number of species die off in a short amount of time relative to background extinction rates (to read more about extinctions, click here).   Some of the major questions being asked include what are the mechanisms behind extinction events and could humans possibly cause a mass extinction?  One of the more recent extinctions in geologic time that may provide some insight into these questions is the Pleistocene megafaunal extinction that occurred in North America.  Three hypotheses have been made on the cause of the Pleistocene extinction, which include: 1) vegetation and climate change, 2) over-hunting by humans, and 3) the introduction of disease brought into North America by humans, the last of which is known as the hyper-disease hypothesis (MacPhee and Marx 1997; Lyons et al. 2004).  Continue reading