A 110,000-year-old bone fragment from the Altai Mountains in Siberia has revealed that two Neanderthals present at the same cave site 10 millennia apart were distant relatives. The bone fragment also yielded the fourth full genome of a Neanderthal. Researchers compared the genome of D17 with the genome from a female Neanderthal dated to 120,000 years ago, which was found to be closely related to D5. This suggests that Neanderthal populations from eastern and western Eurasia became genetically different from each other within a relatively short time frame and within a small geographic area. The study also revealed that Neanderthans in the Altia region lived in very small and highly isolated populations of 50 or fewer people, with stronger genetic markers of inbreeding. The research supports previous studies showing that Neanderthropals lived in smaller and more isolated groups than our own species did.