From a new study out of UC Berkeley:
By combining data from three catalogs of mammal diversity in the United States between 30 million years ago and 500 years ago, UC Berkeley and Penn State researchers show that the bulk of mammal extinctions occurred within a few thousand years after the arrival of humans, with losses dropping after that. Although modern humans emerged from Africa into Europe and Asia by about 40,000 years ago, they didn’t reach North America until about 13,000 years ago, and most mammal extinctions occurred in the subsequent 1,000 to 2,000 years.
The question of our ultimate effect on nature remains up in the air, but it would be naïve to assume that humans are entirely innocent or entirely responsible. That said, the circumstances described here don’t sound that dissimilar to what Darwin describes in On the Origin of Species as the result of a more highly-adapted species moving into a new territory.
