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View Full Version : How old is R1b-L21 in the British Isles?



Krefter
07-28-2015, 01:32 AM
I don't have time, and am too lazy anyways, right now to do the research. So, can knowledgeable people on R1b-L21 post how rooted, diverse, and likely how old R1b-L21 in the British isles is? It's safe to assume it was the main lineage of the Celtic-speakers in Britain and Ireland the Romans knew. But, how long had it been in Britain and Ireland?

Motzart
07-28-2015, 01:56 AM
2500 B.C. was when the Beakers first arrived in Britain.

alan
07-28-2015, 02:54 PM
With so little ancient DNA nothing is safe but inference is exceptionally strong that L21 dominated the pre-Roman Britons. I think L21 must have entered first in the beaker era because there really are no other good candidates for an isles-wide post-Neolithic dominant lineage. However, I think once within the isles L21 would have criss-crossed between Ireland and Britain in both directions many times and probably the same happened across the English channel. So it wont be easy to draw conclusions.

alan
07-28-2015, 02:59 PM
As to why L21 is so dominant in the isles and only moderately represented on the southern side of the channel I can only think we must be looking at founder effects. Either than or L21 had an early dominance that it no longer has on the south side of the English channel. One thing seems clear as dating is tending to push back dates is that the L21 SNP now looks too old to have actually originated in the isles among a P312xL21xDF27xU152 beaker lineage who had migrated there.

Dubhthach
07-28-2015, 06:52 PM
Founder effect I think is important point, if you look at major clades in Ireland they often show multiple "equivalent SNP's" (M222 has what nearly 30 of them!) after which rapid lineage expansion occurs

The only ancient DNA we have from whole region is the Iron age Hinxton remains, until we start seeing aDNA from Bronze age and earlier in the Iron age it's gonna be hard to draw any conclusions. We can at least say that one of Hinxton remains at least know that DF25 arose before 1st century BC.

JRW
08-09-2015, 02:50 PM
Of course, only a significant amount of ancient DNA testing will provide a confident answer. However, from what we have observed from ancient DNA testing to date, the inferences drawn from testing of current populations, and the most recent thinking about the ages of certain haplogroups, L21 may have started to arrive as early as the beaker period. The key take away, however, should be that L21, and more specifically its downstream subclades, continued to flow into the Isles over the next several thousand years -- sometimes as a trickle, and at other times in waves. The majority of L21 represented in the current population of the Isles could have arrived, for example, during the Iron Age. IMO much of the analysis to date (both academic and hobbyist) has been flawed due to looking at L21 in monolithic terms. It is just too old. NGS testing is finally allowing researchers to break through that barrier.

alan
08-09-2015, 03:18 PM
Of course, only a significant amount of ancient DNA testing will provide a confident answer. However, from what we have observed from ancient DNA testing to date, the inferences drawn from testing of current populations, and the most recent thinking about the ages of certain haplogroups, L21 may have started to arrive as early as the beaker period. The key take away, however, should be that L21, and more specifically its downstream subclades, continued to flow into the Isles over the next several thousand years -- sometimes as a trickle, and at other times in waves. The majority of L21 represented in the current population of the Isles could have arrived, for example, during the Iron Age. IMO much of the analysis to date (both academic and hobbyist) has been flawed due to looking at L21 in monolithic terms. It is just too old. NGS testing is finally allowing researchers to break through that barrier.

I agree L21 continued to flow, shed clades and travel. However archaeologically and in terms of subclades its more convincing that L21 clades moved about within the isles rather than multiple waves from the continent. Other than metalwork which is more international, much of the ebb and flow on new pottery, burial trends and ideas seems to within the isles rather than continent. Of course there are contacts with the continent too but it is nowhere near as marked other than in elite metalwork. Even the metalwork is far closer in detail within the isles. The exception to this may be the coastal region of the English channel in France, Belgium and Holland west/south of the Rhine where it has been suggested that there are pottery, burial and settlement parallels with southern Britain - so much so it has been suggested it is a 'maritory'. Perhaps they were L21 too but that is just a guess.

JRW
08-10-2015, 03:32 AM
However archaeologically and in terms of subclades its more convincing that L21 clades moved about within the isles rather than multiple waves from the continent.
There is no doubt that L21 moved within the Isles as well, which only complicates the detection of continental migration. However, what the genetic evidence is showing, rather convincingly in my view, is that despite mostly being composed of men having Isles ancestry, many of L21's not-too-distant downstream subclades suggest having continental origins. Given the variability of the "tightness" of genetic distances among each subclade's Isles members with each other and with their continental cousins, the most likely explanation is that the subclades arrived in the Isles at different times. Of course, poor sampling of the subclade could be a factor.