Geographical origin and dating of the lactase persistence allele

See Dienekes' blog post about a new paper that purports the origin of the lactase persistence allele to be somewhere in the Austria/Czech Republic area, around 7,500 years ago.
From the abstract:

Using data on −13,910*T allele frequency and farming arrival dates across Europe, and approximate Bayesian computation to estimate parameters of interest, we infer that the −13,910*T allele first underwent selection among dairying farmers around 7,500 years ago in a region between the central Balkans and central Europe, possibly in association with the dissemination of the Neolithic Linearbandkeramik culture over Central Europe. Furthermore, our results suggest that natural selection favouring a lactase persistence allele was not higher in northern latitudes through an increased requirement for dietary vitamin D.