Given how much knowledge is required in order to successfully farm and to care for livestock, I'd bet on a peaceful scenario where the more numerous but peaceful farmers traded goods with the more war-like but less numerous hunter/gatherer types and gradually introduced them to farming techniques so that the hunter/gatherer types wouldn't be tempted to hunt their livestock. And, although it's difficult for those of us living in a world of billions of people to wrap our heads around the idea of "not enough people", a small population that was expanding into fertile territory might have been willing to take in any outsiders who wanted to join them. And some of the hunter/gatherers might have envied the food security of the farmers and decided to join them rather than raid them. The Y haplotype I1 that was found could have been a fluke for all we know, but now that I'm thinking about it from that angle, it really does seem to me that it's very difficult to explain the rapid rise of I1 unless I1 people did adopt agriculture fairly early on. The I1 folk appear to have expanded north, for whatever reason, and perhaps that saved them from whatever happened to the G2 farmers.
I agree for the most part. From everything in recent papers about the culture of the foragers at the time of the Neolithic transition, they were not the mobile mammoth hunters of the popular imagination. Rather, whether it was the people living around the Danube Gorges, in Germany (Bollongino et al) or in Gotland, they seem to have been relatively sedentary fisher folk. More like the Indians of the Pacific northwest than the Dakota. (See Boric et al about mobility at this period: Our study unequivocally proves that in the earliest phases of the Neolithic in southeastern Europe, perhaps paradoxically, farming communities were much more mobile than local foraging populations, which in the case of the Danube Gorges remained tied to the exploitation of particular ecological niches since the beginning of the Holocene up until ∼6200 cal B.C. ")
According to the same paper, there seems to have been some absorption of local hunter gatherers,at least in the Danube Gorges area. We also know that from the fact that some samples found in a Neolithic context in Hungary were I1, and in other Neolithic contexts were I2a.
From the paper: "Strontium isotope ratios indicate a dramatic increase in the numbers of nonlocal, first-generation migrants buried in this region at two sites—Lepenski Vir and Ajmana—during the course of Mesolithic–Neolithic transformations in the Danube Gorges (∼6200–6000/5950 cal B.C.) in the sample of 25 securely dated individuals from three sites. This trend continues into the period of the Early/Middle Neolithic after ∼6000/5950 cal B.C. in the sample of 26 securely dated individuals from two sites. Strontium isotope ratios associated with individuals dated to these periods occur outside both the upper and lower boundaries of the defined local strontium range (
Figs. 2 and
3), suggesting at least two or more geologically distinct regions of origin for these incomers."
A change in culture is dramatically apparent not only in the old Mesolithic settlements like Lepinski Vir, but, of course, in the totally new centers established by the newcomers.The authors conclude that "this pattern could be interpreted as suggesting a reciprocal mating network between the Danube Gorges foragers and the earliest farming communities in the surrounding areas, with largely nonlocal women being buried at the central forager site of Lepenski Vir during these phases."
They further go on to state that "important changes were taking place in these forager societies that came under pressure from the growing Neolithic presence in the adjacent areas after ∼6200 cal B.C. (
14,
16,
17). This process of asymmetrical acculturation ended up in a complete absorption of forager specificity in the first several centuries of the sixth millennium B.C."
Furthermore, they state that...As for the Danube Gorges foragers, judging by, at first, a rather organic appropriation and incorporation of new elements of social and material existence as well as biologically “new blood” into the existing modes of being, and, consequently, the abandonment of forager cultural specificity, the mentioned process might have had a predominantly positive connotation or at least represented the only viable solution in the face of the emerging demographics."
That isn't to say that violence didn't occur;the authors also document the discovery of a couple of severed heads. However, the transition seems to have been relatively peaceful.
Given this model, how then are we to make sense of the mtdna findings from the site in Hungary which is the subject of this thread? In Hungary, at least, the U5 lineages which the scholars have been associating with the Mesolithic fisher/foragers form only 10% of the total. Does that mean the wife exchanges were asymmetrical? I don't know. Perhaps forager women, totally foreign to the Neolithic lifestyle, would not have been the first choice for a Neolithic village, while a farmer mate could provide a source of technological expertise in the forager communities? Or, perhaps it was simply a case where the Neolithic farmers just outbred them.
Also, I think we have to keep in mind that the I1 and even the I2a forager lineages are decidedly in the minority. So perhaps we have to think in terms of some absorption of the foragers, but it might be that the majority of them were pushed further to the northeast. There is an analogy in what happened to the North American Indians.
Finally, I think that one has to keep in mind the papers which have argued for a major population crash in central Europe, a population crash which didn't affect southern Europe. How many of the LBK (and related cultures) people remained to encounter the "Indo-Europeans" I don't know, nor do I know the autosomal make-up of this third wave. I would be very surprised, however, if they didn't carry a large EEF component themselves.
