Researchers claim that it was humans and not climate change who played a major role in extinction of ancient mammals including sabretooth tiger, the woolly mammoth, the woolly rhino and the giant armadillo.
A team of researchers led by Lewis Bartlett, of the University of Exeter, base their claims on statistical analysis involving extinction of species, arrival of humans and 90,000 years worth of climate reconstructions.
Published in the journal Ecography, the study examined different regions of the world across these scenarios and found coincidences of human spread and species extinction which illustrate that man was the main agent causing the demise, with climate change exacerbating the number of extinctions. Climate change was also attributed for the extinction of these mammals, but it played a rather smaller role, researchers say.
Though humans have been blamed for extinction of megafauna, in certain regions of the world – mainly in Asia – researchers found patterns which were broadly unaccounted for by either of these two drivers, and called for renewed focus on these neglected areas for further study.
Dr Andrea Manica, of Cambridge University, was lead supervisor on the paper. He said: “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.”
According to Lewis Bartlett, a researcher from the University of Exeter’s Centre for Ecology and Conservation, their findings are more or less like the ‘nail in the coffin of this 50-year debate’.
“…humans were the dominant cause of the extinction of megafauna”, said Bartlett. However, the researchers added that they do not know the details about these early settlers who caused this demise or why did they kill the giant mammals – was it for food or something else?
“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.”