A HANDFUL of amorous Neanderthals - possibly as few as 20 individuals - are likely to have provided all the DNA originating from the species which is found in modern humans, a new study has indicated. But the Denisovans, a lesser-understood branch of the human family, are likely to have intermixed with modern humans in at least two distinct mixing events, meaning DNA from them makes up a higher proportion of the genetic code of some populations of people living in east Asia and Oceania. The study offers the most comprehensive analysis of human genetic diversity to date, after the sequencing of 929 human genomes by scientists at the Wellcome Sanger Institute, the University of Cambridge and collaborators. It suggests Neanderthal ancestry of modern humans can be explained by just one major mixing event, probably involving several Neanderthal individuals who came into contact with modern humans shortly after the latter had expanded out of Africa. The study's first author, Dr Anders