Some 11,000 years ago the American West was the site of some inter-species mammoth lovin', researchers say. Scientists analyzing the DNA of mammoths unearthed in Utah and Wyoming were amazed to find that the mitochondrial genome of what they believed was a Columbian mammoth—which thrived in warm parts of the Americas—was nearly identical to that of woolly mammoths, who preferred the Arctic tundra, the Christian Science Monitor reports.
"We think we may be looking at a genetic hybrid," says a researcher who believes the woolly mammoths must have regularly interbred with the other, much larger species as Arctic conditions worsened and the huge beasts migrated south. The larger mammoths likely out-competed the smaller for mates, as happens with different species of African elephants when their ranges overlap. "It reminds me a bit of high-school days—the larger males are more successful at meeting women across the dance floor than the rest of us," the researcher quipped. (Read more woolly mammoth stories.)