New Study Says Ancient Humans Hunted Big Mammals To Extinction
Over the past 125,000 years, the average size of mammals on the Earth has shrunk. And humans are to blame. That's the conclusion of a new study of the fossil record by paleo-biologist Felisa Smith of the University of New Mexico. Smith studied fossils going back 65 million years, when dinosaurs died and mammals came into their own. Many of the early mammals went on to get big. Among the giant creatures: "Llamas and camels and sloths and five species of pronghorn [antelope] actually," she says, "and certainly mammoths.