Neanderthal inheritance helped humans adapt to life outside of Africa

As the ancestors of modern humans made their way out of Africa to other parts of the world many thousands of years ago, they met up and in some cases had children with other forms of humans, including the Neanderthals and Denisovans. Scientists know this because traces of those meetings remain in the human genome. Now, researchers find more evidence that those encounters have benefited humans over the years.