The human family tree is gaining new branches. Researchers have found in modern humans' DNA signs of two previously unknown ancestors – extinct human forms with no fossils or decoded DNA, yet they have left traces in our genome.

Scientists analyzing modern genomes may have found a long-lost branch of the human family tree

Neanderthals and Denisovans interbred with modern human ancestors, leaving behind telltale DNA in our genomes. Now we have evidence of modern human interbreeding with two much…