On a brighter note, here are some interesting Identity-by-Descent (IBD) maps from a very competent new preprint at bioRxiv on the admixture history of Siberians. You'll find the full collection in the paper's supp info PDF here.
Furthermore, our results demonstrate that the European ancestry component detectable in many populations of southern, central, and northern Siberia is not the result of post-colonial Russian admixture as may have been expected  and as was suggested on the basis of ALDER analyses . Rather, with the exception of the Dolgans and the Samoyedic-speaking groups of western Siberia, the European ancestry represents one of the most ancient components [dating to not more than 4500 years ago] of the complex admixture history of Siberian populations.
The ~4,500 YBP date makes a lot of sense. This is the Late Neolithic/Early Bronze Age period, which also saw massive population movements from the steppe deep into Europe (see here).
Pugach et al., The complex admixture history and recent southern origins of Siberian populations, bioRxiv, Posted April 30, 2015, doi: http://dx.doi.org/10.1101/018770