Destroyer of Worlds

[n2doc]

2. from the article

A few months ago, a well-publicised paper claimed that the great beasts of the Americas – mammoths and mastodons, giant ground sloths, lions and sabretooths, eight-foot beavers(8), a bird with a 26-foot wingspan(9) – could not have been exterminated by humans, because the fossil evidence for their extinction marginally pre-dates the evidence for human arrival(10).

I have never seen a paper demolished as elegantly and decisively as this was at last week’s conference. The archaeologist Todd Surovell demonstrated that the mismatch is just what you would expect if humans were responsible(11). Mass destruction is easy to detect in the fossil record: in one layer bones are everywhere, in the next they are nowhere. But people living at low densities with basic technologies leave almost no traces. With the human growth rates and kill rates you’d expect in the first pulse of settlement (about 14,000 years ago), the great beasts would have lasted only 1,000 years. His work suggests that the most reliable indicator of human arrival in the fossil record is a wave of large mammal extinctions.