Some like to argue about alleged haplogroup age estimates based on various versions of the molecular clock hypothesis. I just shrug at that. I find geographic and (pre-)historical patterns to be much more substantive. In what regards to me, they should use them to modify their estimates appropiately and maybe that way they would reach to some reasonable MC estimation system.
It's just common sense. For example, Dienekes was recently arguing that haplogroup E-V13 (E1b1a2 by the 2008 nomenclature) had to be of the Bronze Age (he has his own even shorter version of MCH) but I protested that the distribution pattern is only consistent with Neolithic spread (and by no means with Greek historical coastal colonization). A map is worth a thousand words:
The above map's pink shades show the density of E-V13 (the increase towards Finland is just an effect of lack of data for that region though). On it I have added blue lines representing the extent of Balcanic-derived Neolithic waves in Europe. BN stands for Balcanic Neolithic (including Sesklo-derived, Eastern Lineal Pottery and Grey-Black Pottery cultures), and the thick oval in it is the Thessalian region of origin (notice that Sesklo-Dimini, at the origin of most European Neolithic, is as high in E-V13 as Albania, if not even more). DN stands for Danubian Neolithic (aka Western Lineal Pottery) and MN for Mediterranean Neolithic (aka Cardium Pottery), both more or less clearly related to Sesklo and the Balcanic Neolithic.
For me the pattern is very clear: it is a Neolithic clade. And there is no way it can have another explanation.
Another clade often subject to discussion among the MCH fans is the most common Western European haplogroup: R1b1b2 (formerly R1b1c). Some argue it should be Neolithic or even more recent. But its distribution pattern is by no means coincident with Neolithic expansion.
Again a map is worth a thousand words. Even better: two maps:
The above maps show (roughly) the density of R1b1b2 (red-pink shades). Map A shows the origin (purple oval and star) and expansion (blue lines) of Magdalenian culture, as well as of epi-Magdalenian derivates (green). I understand that the Magdalenian-origin interpretation is the only possible one, the patterns being almost exact.
Map B illustrates the only possible Neolithic (or rather Chalcolithic) explanation for R1b1b2 spread: Western Megalithism. The purple oval and star indicate the origin, the blue lines max. expansion and the green lines those areas lost to Indoeuropean expansion c. 2400 BCE. Nevertheless, I understand that Megalithism was not related to any major demic expansion but it was mostly a cultural phenomenon spreading into native groups. We cannot exclude some localized colonizations and it is even possible that some haplotypes might have spread with this cultural/religious phenomenon - but that would be all.
The only intriguing issue is the relatively high R1b1b2 in Italy, that was not part of Magdalenian culture but was of Western Gravettian, where the clade may have its ultimate source. It could be argued that higher density in the subalpine area means Indoeuropean infiltration in proto-historical times from the other side of the Alps. Alternatively it could mean that the origin of R1b1b2 is a Western Gravettian founder effect (with R1b1b1 being maybe part of Eastern Gravettian). Whatever the case, there is no logical way it could be of Neolithic or Chalcolithic origin.
And that's all for today.