Geneticists exploring the dark heart of the human genome have discovered big chunks of Neanderthal and other ancient DNA. The results open new ways to study both how chromosomes behave during cell division and how they have changed during human evolution.
If discovered as fossils, grey and ringed seals are so different that they could be classified as belonging to different families. Yet, a seal pup born in 1929 was found to be an almost perfect intermediate between the species. Compared to Neanderthals and modern humans, grey and ringed seals are genetically and dentally at least twice as different, suggesting that there may be more fossil human hybrids to be discovered.