An article published in the journal “PLOS Genetics” reports a genetic study showing the traces of various interbreedings between different species of hominins. Melissa Hubisz and Amy Williams of Cornell University and Adam Siepel of Cold Spring Harbor Laboratory developed a genetic analysis software that can recognize relations and applied it to a group of genomes that includes two Neanderthals, a Denisovan, and two African modern humans. The result is evidence that 3% of Neanderthal DNA came from ancient humans in an interbreeding between 200,000 and 300,000 years ago, 1% of Denisovan DNA came from an older species, maybe Homo erectus, and 15% of that “superarchaic” DNA may have been passed on to modern humans.