One paper comes out saying one thing and a few weeks later there is a paper demonstrating the opposite – and genetics has been a bit like that. Are we getting some realism into the genetics of our human forebears – who knows, it's all a bit of a lottery. The journal Trends in Genetics, see http://phys.org/print264159758.html … is taking a relook into the evolution of humans in Europe, trying to fit the pieces together in what is a complex picture book of data, no easy task. After the Ice Age hunter gatherers, in the so called Mesolithic period, quickly recolonised large parts of NW Europe that had formerly been under an ice sheet or was inhospitable tundra. After 6000BC, farmers appear to have entered Europe by way of Anatolia bringing with them a completely different lifestyle. For too many years it has been assumed the genetic diversity of modern Europeans was shaped mainly during the Neolithic. It now appears this was a bit naive, a simple juggling of the data that fitted, once again, a consensus opinion. Now the facts are being taken out again and are being given a brush down. The genetic diversity of Europeans, it emerges, was shaped by events before 6000BC and by events that occurred long after the introduction of farming. Not only that, it is now recognised the spread of farming led to variations from region to region, depending on if the local Mesolithic people moved away or were absorbed.
See also R Piakosi, Trinity College, Dublin, et al 'The genetic history of Europeans' at dx.doi.org/10.1016/j.tig.2012.06.006