Really.... At roughly 3.2 billion base pairs, the Neanderthal genome is about the size of the modern human genome. According to preliminary sequences, 99.7% of the base pairs of the modern human and Neanderthal genomes are identical, compared to humans Additionally, in 2010, the announcement of the discovery and analysis of Mitochondrial DNA (mtDNA) from the Denisova hominin in Siberia revealed that this specimen differs from that of modern humans by 385 bases (nucleotides) in the mtDNA strand out of approximately 16,500, whereas the difference between modern humans and Neanderthals is around 202 bases.
Right, and the next sentence in that paragraph (from the Wikipedia page for the Neanderthal Genome Project) is : "In contrast, the difference between chimpanzees
and modern humans is approximately 1,462 mtDNA base pairs."
Interestingly the article those numbers come from is also linked to in the Wikipedia page, here it is :
I hope everyone can access it, it's under a Creative Commons license so I assume so.
As it turns out in their comparison they used 54 human genomes and one genome from a modern human fossil from the Pleistocene; here is the graph they get on the pairwise comparisons between all those human, Denisovan and Neanderthal genomes :
I assume there are two maxima for "Human-Human comparisons" because one of them is the Pleistocene human genome. But for those who can't see the graph, here are the nucleotide differences they get for all those comparisons :
Modern human/Modern human : 0-70 for present-day humans, 70-105 for the Pleistocene human (with some overlap)
Modern human/Neanderthal : 180-220
Modern human/Denisovan : 370-400
Modern human/Chimpanzee : 1462 (not on the graph so I don't have the range)
Both Neanderthals and Denisovans are clearly distinct from modern humans in this comparison, and Denisovans are not only almost twice as different from us as Neanderthals are, they're less than a fourth more different from us than Chimpanzees are.
EDIT : Actually considering the number of comparisons involved in the two human/human maxima and the phylogenetic tree they also show it doesn't seem likely it represents that single Pleistocene human's genome; it might be a Central Africa/vs Eurasia thing instead. Either way that second maximum represents under half the differences one finds when comparing with Neanderthals.