Underwater Bahamian fossils suggest humans were a bigger factor in extinctions than climate

Los Angeles Times : Between 10 000 and 11 000 years ago, many species around the world, including woolly mammoths and saber-toothed cats, went extinct. Two factors—the spread of humans and a significant change in global climate—are considered to be the primary causes for the extinctions, but the impact of each factor has been difficult to measure. A team led by David Steadman of the Florida Museum of Natural History has used isolated, underwater fossil sites in the Bahamas to try to distinguish between the two factors. Previous studies have shown that extinctions have commonly occurred on islands soon after humans colonized them. The discovery of a collection of fossils in an area that had been underwater at least 11 000 years ago—long before humans arrived there—allowed Steadman’s team to determine which species died off due to climate change and which survived until the more recent human presence on the islands. They found that the vast majority of the species only went extinct following the arrival of humans.