45 thousand years ago is probably close to when Eurasians started diverging from each other as they spread in all directions. So, we expect that a human from that time would be "undifferentiated Eurasian" and indeed this seems to be the case.
First the Y-chromosome:
The Y chromosome sequence of the Ust’-Ishim individual is similarly inferred to be ancestral to a group of related Y chromosomes (haplogroup K(xLT)) that occurs across Eurasia today6 (Supplementary Information section 9).and mtDNA:
The Ust’-Ishim mtDNA sequence falls at the root of a large group of related mtDNAs (the ‘R haplogroup’), which occurs today across Eurasia (Supplementary Information section 8).It is clear that this was a Eurasian individual:
Based on genotyping data for 87 African and 108 non-African individuals (Supplementary Information section 11), the Ust’-Ishim genome shares more alleles with non-Africans than with sub-Saharan Africans (|Z| = 41–89), consistent with the principal component analysis, mtDNA and Y chromosome results.It was also more like East Asians than Europeans:
Among the non-Africans, the Ust’-Ishim genome shares more derived alleles with present-day people from East Asia than with present-day Europeans (|Z| = 2.1–6.4).
However, when an ~8,000-year-old genome from western Europe (La Braña)9 or a 24,000-year-old genome from Siberia (Mal’ta 1)10 were analysed, there is no evidence that the Ust’-Ishim genome shares more derived alleles with present-day East Asians than with these prehistoric individuals (|Z| < 2). This suggests that the population to which the Ust’-Ishim individual belonged diverged from the ancestors of present-day West Eurasian and East Eurasian populations before—or simultaneously with—their divergence from each other. The finding that the Ust’-Ishim individual is equally closely related to present-day Asians and to 8,000- to 24,000-year-old individuals from western Eurasia, but not to present-day Europeans, is compatible with the hypothesis that present-day Europeans derive some of their ancestry from a population that did not participate in the initial dispersals of modern humans into Europe and Asia11.So it seems that the Ust'-Ishim individual belonged to the same branch as Asians and WHG/ANE and modern Europeans are less like it because they also have "Basal Eurasian" admixture which they inherited via the EEF in the model of Lazaridis et al.
The authors could also get estimates of the mutation rate because this is a 45,000 year old individual that hasn't experienced 45,000 years worth of mutations:
Assuming that this corresponds to the number of mutations that have accumulated over around 45,000 years, we estimate a mutation rate of 0.43 × 10−9 per site per year (95% CI 0.38 × 10−9 to 0.49 × 10−9) that is consistent across all non-African genomes regardless of their coverage (Supplementary Information section 14). This overall rate, as well as the relative rates inferred for different mutational classes (transversions, non-CpG transitions, and CpG transitions), is similar to the rate observed for de novo estimates from human pedigrees (~0.5 × 10−9 per site per year14, 15) and to the direct estimate of branch shortening (Supplementary Information section 10). As discussed elsewhere14, 16, 17, these rates are slower than those estimated using calibrations based on the fossil record and thus suggest older dates for the splits of modern human and archaic populations.This is a very direct confirmation of the "slow" autosomal rate of ~1.2x10-8 mutations/generation/bp using a technology much different than those used before to estimate this. The slower mutation rate implies that major splits in human history (such as the Out-of-Africa event) took place much earlier than the Upper Paleolithic revolution and the spread of humans across Eurasia. Modern humans probably established an early presence in the Levant/Arabia (consistent with Out-of-Arabia), and invented the Upper Paleolithic-related tools/behaviors there much later, and only then spread across Eurasia.
The authors write:
we estimate that the admixture between the ancestors of the Ust’-Ishim individual and Neanderthals occurred approximately 50,000 to 60,000 years BP, which is close to the time of the major expansion of modern humans out of Africa and the Middle East.This clinches the hypothesis of Neandertal introgression in Eurasians, as Ust'-Ishim has longer Neandertal segments than modern humans, as one might expect from an individual who experienced this admixture more recently in its evolutionary past than modern humans did. It's probably in the Middle East that the Levantine/Arabian modern humans that expanded Out-of-Africa more than 100 thousand years ago came into contact with Neandertals, admixed with them and later carried this ancestry to the rest of Eurasia. I tend to think that the AMH "colony" was first limited to Arabia and only later (post-70kya) expanded north as the climate deteriorated there. The authors estimate the common ancestor of non-African Y-chromosomes (including E, which is probably a back-migration to Africa) to around 70 thousand years ago which may coincide with the Arabian Exodus event.
Nature 514, 445–449 (23 October 2014) doi:10.1038/nature13810
Genome sequence of a 45,000-year-old modern human from western Siberia
Qiaomei Fu et al.
We present the high-quality genome sequence of a ~45,000-year-old modern human male from Siberia. This individual derives from a population that lived before—or simultaneously with—the separation of the populations in western and eastern Eurasia and carries a similar amount of Neanderthal ancestry as present-day Eurasians. However, the genomic segments of Neanderthal ancestry are substantially longer than those observed in present-day individuals, indicating that Neanderthal gene flow into the ancestors of this individual occurred 7,000–13,000 years before he lived. We estimate an autosomal mutation rate of 0.4 × 10−9 to 0.6 × 10−9 per site per year, a Y chromosomal mutation rate of 0.7 × 10−9 to 0.9 × 10−9 per site per year based on the additional substitutions that have occurred in present-day non-Africans compared to this genome, and a mitochondrial mutation rate of 1.8 × 10−8 to 3.2 × 10−8 per site per year based on the age of the bone.