The Pleistocene brought about the words most recent period of glaciation, and with its end a great loss of terrestrial megafauna such as the Genera Megatherium, the giant land sloths and Coelodonta, the woolly rhinoceros'. The cause of these extinctions has been debated among the scientific community for decades, whether synonymous with climate change and the large deglaciation at the end of the Pleistocene, or the rise of Homo sapiens, hunting these animals to extinction, dubbed the "Overkill" hypothesis. The evidence for and against each cause is overwhelming, and the reality is much simpler.
Overkill Hypothesis:
Let us start with the fact that during this period of humanity's migration across the globe, megafauna genera were butchered, North America and South America lost 33 and 46 genera respectively in the last 100,000 years alone (Martin 1984). However, among this great loss another strange trend grew, small fauna at the time, such as rats, did not experience the same sweeping extinction rates as the coexistent megafauna of …show more content…
Using just north America as the sample area and entering realistic factors like life expectancy (about 25 years) and human population growth rate, which varied dependent on the variables that were being tested, 7 in all, shown above in Figure 1.
These simulations calculated how long the growing population of hunters wold take to cause a megafaunal extinction given certain pre-sets, and all, excluding the test designed to let fauna survive, calculate an extinction within 1,200 years of the arrival of humans into North America. These are realistic values, and given that all pre-set variables are realistic situations, they provide foundations, not an answer, to the definitive answer of "prehistoric overkill".
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