A new study says Neanderthals and humans likely mixed and mingled during a narrow time frame 45,000 years ago. Researchers analyzed ancient genes to pinpoint the time period, which is slightly more recent than previous estimates for the mating. Modern humans emerged in Africa hundreds of thousands of years ago and eventually spread to Europe, Asia and beyond. Somewhere along the way, they mated with Neanderthals. We still carry Neanderthals’ legacy in our DNA, and future genetic studies can help scientists detangle exactly what — and who — we’re made of. The research published Thursday in the journals Science and Nature.