Ancient linkups may have happened more frequently between female humans and male Neanderthals, according to an new genetic analysis. Scientists know that Neanderthals and humans mated because there is a small percentage of Neanderthal DNA in most modern humans. But they also know that the Neanderthal DNA is not distributed evenly throughout the human genome. Scientists looked at the human genes that got interspersed with Neanderthal ones during an ancient mating event and saw a surprising human fingerprint that told them the explanation may be mating behavior. The new study was published Thursday in the journal Science.