Modern humans have wiped out countless species across the globe, but new research suggests our early ancestors were also responsible for major extinctions in the animal kingdom.
A recent study found early humans caused the extinction of a variety of species of giant beasts, the University of Exeter reported. These findings could help settle once and for all whether climate change or human activity wiped out ancient behemoths such as the sabretooth tiger, the woolly mammoth, the woolly rhino and the giant armadillo. This group of animals, known of as megafauna, had all gone extinct by about 10,000 years ago, but the reason why has been a source of debate among the science community.
"As far as we are concerned, this research is the nail in the coffin of this 50-year debate - humans were the dominant cause of the extinction of megafauna. What we don't know is what it was about these early settlers that caused this demise. Were they killing them for food, was it early use of fire or were they driven out of their habitats? Our analysis doesn't differentiate, but we can say that it was caused by human activity more than by climate change. It debunks the myth of early humans living in harmony with nature," said Lewis Bartlett, a researcher from the University of Exeter's Centre for Ecology and Conservation.
To make their findings, the researchers used "cutting-edge" statistical analysis techniques. The results suggested early humans were the main driver of the extinction of megafauna, but climate change may have also had a small effect. The team ran thousands of scenarios, which effectively mapped the windows of time in which each species disappeared and when humans arrived in different regions. These results were compared against climate reconstructions for the last 90,000 years.
The analysis revealed correlations between humans spreading to different areas and species extinction, suggesting man was the primary cause of their disappearance. The researchers noted they did find some instances (mostly in Asia) in which the patterns were largely unaccounted for by either extinction factor, highlighting the need for more research to be done on these regions.
"Whilst our models explain very well the timing and extent of extinctions for most of the world, mainland Asia remains a mystery. According to the fossil record, that region suffered very low rates of extinctions. Understanding why megafauna in mainland Asia is so resilient is the next big question,"
The findings were published in a recent edition of the journal Ecography.