The number crunching to arrive at this startling conclusion were extensive:
The researchers ran thousands of scenarios which mapped the windows of time in which each species is known to have become extinct, and humans are known to have arrived on different continents or islands. This was compared against climate reconstructions for the last 90,000 years.
Examining different regions of the world across these scenarios, they 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. However, in certain regions of the world — mainly in Asia — they found patterns which patterns were broadly unaccounted for by either of these two drivers, and called for renewed focus on these neglected areas for further study.
Bartlett says that this really is the “nail in the coffin” of the debate about what caused the demise of the so-called megafauna, and without a doubt they conclude that humans were the reason.
Further details and additional references can be found in the excellent and detailed article on Science Daily.
Source: Humans responsible for demise of gigantic ancient mammals, on ScienceDaily.com
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