It's relatively small paper compared to the mastodons published earlier this month, but nevertheless interesting.

Paleogenomic Evidence for Multi-generational Mixing between Neolithic Farmers and Mesolithic Hunter-Gatherers in the Lower Danube Basin (extended PDF with supplementary materials here)

Summary

"The transition from hunting and gathering to farming involved profound cultural and technological changes. In Western and Central Europe, these changes occurred rapidly and synchronously after the arrival of early farmers of Anatolian origin, who largely replaced the local Mesolithic hunter-gatherers. Further east, in the Baltic region, the transition was gradual, with little or no genetic input from incoming farmers. Here we use ancient DNA to investigate the relationship between hunter-gatherers and farmers in the Lower Danube basin, a geographically intermediate area that is characterized by a rapid Neolithic transition but also by the presence of archaeological evidence that points to cultural exchange, and thus possible admixture, between hunter-gatherers and farmers. We recovered four human paleogenomes (1.1× to 4.1× coverage) from Romania spanning a time transect between 8.8 thousand years ago (kya) and 5.4 kya and supplemented them with two Mesolithic genomes (1.7× and 5.3×) from Spain to provide further context on the genetic background of Mesolithic Europe. Our results show major Western hunter-gatherer (WHG) ancestry in a Romanian Eneolithic sample with a minor, but sizeable, contribution from Anatolian farmers, suggesting multiple admixture events between hunter-gatherers and farmers. Dietary stable-isotope analysis of this sample suggests a mixed terrestrial/aquatic diet. Our results provide support for complex interactions among hunter-gatherers and farmers in the Danube basin, demonstrating that in some regions, demic and cultural diffusion were not mutually exclusive, but merely the ends of a continuum for the process of Neolithization."

The three Mesolithic southern Romanians belonged to Y-DNA/mtDNA haplogroups R/U5b2c, R1/U5a1c and R1b/K1 + 16362.

The two Mesolithic northwest Spaniards are female and belong to mtDNA haplogroups U5a2a and U5b.

A female Eneolithic sample (5,375 cal BP) from Gura Baciului in central Romania was also tested and belonged to K1a4a.

All Mesolithic samples were pure Mesolithic European autosomally (apparently only WHG). The Chalcolithic sample was about 65% Mesolithic HG, 30% Neolithic farmer and 5% of Steppe/EHG (without CHG).

They also report derived alleles for pigmentation and lactose tolerance. All Mesolithic samples had dark eyes, hair and skin, except one blue-eyed Spaniard. In contrast the Copper Age Romanian had fair skin, blue eyes and possibly lighter brown hair than the others. None of them had derived MC1R mutations for red hair. None of them were able to digest lactose.

Of course the paper would have been much more interesting (for us) if it had been published before the Mathiesen et al. (2017) preprint two weeks ago, but at least this is the definitive paper.