The genetic complexity of prehistoric Sweden

Thanks to the fact that northern Europe is cool and archaeological research is rather well developed in the region due to quirks of history, there are lots of findings from ancient DNA which are answering long-standing questions. In particular Scandinavia is of special interest in regards to the transition of Europeans from a hunter-gatherer lifestyle to an agricultural one. We know that hunting and gathering as dominant modes of economic production persisted relatively late in European history in this region, up to ~5,000 years before the present. From my cursory reading of the material on the spread of agriculture in northern Europe one dynamic which seems clear is that the rate of expansion was not always constant, and that at the northern fringes in particular social or ecological frontiers served to demarcate the limits to the expansion of farming groups, which often originated from the south and east. Additionally, on the maritime fringes of the North Sea and Baltic there seem to have been relatively dense agglomerations of hunter-gatherers which resisted or coexisted with farming populations for long periods of time (perhaps they were more accurately termed fisher-gatherers!). This is where Anna Linderholm's research comes into the picture. I've blogged some of her work before. Linderholm's goal seems to be to synthesize a range of results from disparate fields in understanding how two partially contemporaneous prehistoric Scandinavian cultures related to each other: the Pitted Ware Culture (PWC) and the Funnelbeaker Culture (TRB, which is an acronym for the German name for the culture). The former were hunter-gatherers who tended to rely upon marine resources, while the latter were agriculturalists who engaged in a great deal of animal husbandry. You can find her contribution to the book Human Bioarchaeology of the Transition to Agricultureonline. It's pretty accessible for an ignorant lay person, and in the chapter she outlines some really interesting detail about the relationship between the PCW, TRB, modern northern European populations, and the functional genetic characteristics of these ancient groups. The basic chronological outline seems to be that around 3000 BCE there was a period of hundreds of years of contemporaneous habitation of southern Sweden by the TRB and PCW cultures, though they were spatially segregated. TRB finds seem to be concentrated in inland regions, while PCW were found on the maritime fringe. Additionally, the island of Oland in the Baltic exhibited nearly 1,000 years of coexistence of the two cultures. After 2000 BCE these cultures eventually disappeared and gave way to a homogeneous agricultural Bronze Age society. Were the two cultures of southern Sweden during the Neolithic simply two modes of production of the same people? And were these the ancestors of modern day Swedes? And what can biological anthropology tell us about what they ate and how they ate? Let's start with mtDNA relationships: