alan
06-13-2014, 05:36 PM
Initial dispersal across Europe is what I am talking about. There are still some people who think R1b is older is western Europe than the main body of opinion. I think its worth considering the maximum age R1b dispersal across Europe could be without special pleading based on low numbers of clades that are much more common well to the east.
I think the key to this is the L23 SNP. IMO it unites so much of European R1b that it is as high up the chain as one can go when looking for the earliest possible dispersal. I do not believe it is credible to look at all L23 as having spread from a western source and somehow ended up all across Europe and SW Asia. There is just no cultures that did that in the archaeological record. IMO L23 or true L23*(something that doesnt exist today) is the earliest realistic option for how much of Eurasian L23 derived R1b could have spread.
If some L23* dispersed thinly across Europe then from differing position the L23xL51 and L51 derived groups could have sprung in a couple of different localities. L23xL51 lines could have sprung up in the area around SE Europe and L51 could have sprung up in west central or Alpine Europe for example.
The question is whether this is credible or not and the date. I think SNP counting seriously trumps STRs/fudge factors etc. Recently Michal came up with dates for the L23 SNP as well as the MRCA for L51 and the L23xL51 clades. He placed the L23 SNP at around 6300BC with upstream M269 only a couple of centuries older. That for me is the absolutely earliest sort of date that even in theory L23 could have dispersed in a way that would have allowed later localised rise of L23 derived clades at different areas. So, it would theoretically allow just about for a Neolithic dispersal but IMO it is absurd to even contemplate a pre-farming origin in western Europe. That now IMO needs put to bed permanently and officially designated a crazy/biased model to stand by today.
Interestingly Michal placed L51, L23xL51 and M269* clades all at similar dates around 5500BC. This shows a delay between the age of the L23 SNP and the arising of clades that survive today. Now, IMO this actually suggests that L23 had not widely dispersed by this period. Otherwise why would all the surviving early branchings of L23 take off/get to an 'above survival' demographic level at the same time? On the contrary it suggests all three early branches of L23 found itself suddenly in more favourable circumstances/environment/socio-economics simultaneously. That to me suggests they were not hugely dispersed and in a broadly similar zone at that moment in time of simultaneous expansion. Two of the three early L23 splits focus on the Balkans in European terms today while L51* is too small to have confidence but looks broadly Alpine. I would say the centre of gravity collectively would still point roughly towards the Balkans.
Where was that zone? Well these early dated L23 clades are today spread mainly across SE Europe and the Alps in European terms and into SW Asia too. I can conceive of no dispersal from west to east between the exceptions to that rule in the Magdallenian (far too early) and bell beaker (far too late). So, I would say that a pan Eurasian lineage like L23 and derived must have been in the east somewhere. As for the date, there are of course problems with all methods. I would tend to look at the evidence and think this expansion took place from a source not further west than the Balkans.
As to the date itself, why would c. 5500BC see L23 suddenly kick into life and produce surviving branches after doing nothing for 1000 years? Well dates are obviously still a problem although I think the SNP counting method is the way to go. Ancient DNA would appear to confirm a lack of L23 or any R1b in central, northern, southern and western Europe in the period before 5500BC that Michal's dating would suggest. So, I think, given that most R1b in the western half of Europe is L51 derived and that and all survving L23 clades are dated by Michael to c. 5500BC is in agreement with the ancient DNA evidence for an absence of it in the main body of Europe in the Neolithic.
What is the significance of c. 5500BC to the sudden simultaneous take off of L23 derived surviving clades? Obviously we cannot take the date too literally given all the uncertainties. Also we need to bare in mind that western Europe is mainly L11 derived, something that SNP dating is unlikely to place much before 4500BC. I suggest we should not be looking further west than the Balkans for the early take off of L23 derived clades. I do not believe it can be linked to the Koros-LBK kind of chain of cultures which indeed ancient DNA seems to show are R1b-free. Koros is linked to the Cris and Starcevo cultures and I would tend to think they too should probably therefore also be seen as an unlikely Balkans home for the L23 early clade emergence. It would appear to me in a generic way that the take off of L23 clades around this time is likely to relate to influences of farming reaching local groups in or close to the Balkans.
I think the key to this is the L23 SNP. IMO it unites so much of European R1b that it is as high up the chain as one can go when looking for the earliest possible dispersal. I do not believe it is credible to look at all L23 as having spread from a western source and somehow ended up all across Europe and SW Asia. There is just no cultures that did that in the archaeological record. IMO L23 or true L23*(something that doesnt exist today) is the earliest realistic option for how much of Eurasian L23 derived R1b could have spread.
If some L23* dispersed thinly across Europe then from differing position the L23xL51 and L51 derived groups could have sprung in a couple of different localities. L23xL51 lines could have sprung up in the area around SE Europe and L51 could have sprung up in west central or Alpine Europe for example.
The question is whether this is credible or not and the date. I think SNP counting seriously trumps STRs/fudge factors etc. Recently Michal came up with dates for the L23 SNP as well as the MRCA for L51 and the L23xL51 clades. He placed the L23 SNP at around 6300BC with upstream M269 only a couple of centuries older. That for me is the absolutely earliest sort of date that even in theory L23 could have dispersed in a way that would have allowed later localised rise of L23 derived clades at different areas. So, it would theoretically allow just about for a Neolithic dispersal but IMO it is absurd to even contemplate a pre-farming origin in western Europe. That now IMO needs put to bed permanently and officially designated a crazy/biased model to stand by today.
Interestingly Michal placed L51, L23xL51 and M269* clades all at similar dates around 5500BC. This shows a delay between the age of the L23 SNP and the arising of clades that survive today. Now, IMO this actually suggests that L23 had not widely dispersed by this period. Otherwise why would all the surviving early branchings of L23 take off/get to an 'above survival' demographic level at the same time? On the contrary it suggests all three early branches of L23 found itself suddenly in more favourable circumstances/environment/socio-economics simultaneously. That to me suggests they were not hugely dispersed and in a broadly similar zone at that moment in time of simultaneous expansion. Two of the three early L23 splits focus on the Balkans in European terms today while L51* is too small to have confidence but looks broadly Alpine. I would say the centre of gravity collectively would still point roughly towards the Balkans.
Where was that zone? Well these early dated L23 clades are today spread mainly across SE Europe and the Alps in European terms and into SW Asia too. I can conceive of no dispersal from west to east between the exceptions to that rule in the Magdallenian (far too early) and bell beaker (far too late). So, I would say that a pan Eurasian lineage like L23 and derived must have been in the east somewhere. As for the date, there are of course problems with all methods. I would tend to look at the evidence and think this expansion took place from a source not further west than the Balkans.
As to the date itself, why would c. 5500BC see L23 suddenly kick into life and produce surviving branches after doing nothing for 1000 years? Well dates are obviously still a problem although I think the SNP counting method is the way to go. Ancient DNA would appear to confirm a lack of L23 or any R1b in central, northern, southern and western Europe in the period before 5500BC that Michal's dating would suggest. So, I think, given that most R1b in the western half of Europe is L51 derived and that and all survving L23 clades are dated by Michael to c. 5500BC is in agreement with the ancient DNA evidence for an absence of it in the main body of Europe in the Neolithic.
What is the significance of c. 5500BC to the sudden simultaneous take off of L23 derived surviving clades? Obviously we cannot take the date too literally given all the uncertainties. Also we need to bare in mind that western Europe is mainly L11 derived, something that SNP dating is unlikely to place much before 4500BC. I suggest we should not be looking further west than the Balkans for the early take off of L23 derived clades. I do not believe it can be linked to the Koros-LBK kind of chain of cultures which indeed ancient DNA seems to show are R1b-free. Koros is linked to the Cris and Starcevo cultures and I would tend to think they too should probably therefore also be seen as an unlikely Balkans home for the L23 early clade emergence. It would appear to me in a generic way that the take off of L23 clades around this time is likely to relate to influences of farming reaching local groups in or close to the Balkans.