GailT
08-19-2012, 09:31 PM
A very interesting paper was published in June that includes the full mtDNA genome for 7000 year old late Mesolothic sample in Spain, U5b2c1. There is some discussion of the paper at Dienekes blog (http://dienekes.blogspot.com/2012/06/mesolithic-iberians-la-brana-arintero.html).
The sample appears to be U5b2c1 with no additional mutations reported in Table S2. We have 5 FMS test results in the U5 project for U5b2c1 and 1 partial result from Hernstadt. One person in the project has ancestry in Spain and also has no extra mutations, i.e., this person is an exact match to the Mesolithic La Brana sample. Two U5b2c1 people have ancestry in Ireland, and one has ancestry in Germany. They have between 1 to 5 extra mutations for an average of 2.17 and age estimate of 5700 years (compared to Berhar's estimate of 4200 years). Both estimates are younger than the remains dated to 7,000 years old. However, the age estimates are based on a small sample size and have large uncertainty. The FMS test result is very useful for an independent estimate of the age of U5b2c1, and it confirms a very old date for this group and also confirms that it was present in Europe during the late Mesolithic.
For comparison with other U5b2c in the FTDNA U5 project, we have one U5b2c* with ancestry in Ireland, we have two U5b2c2 with ancestry in Ireland and and 1 in Scotland. We also have 5 people in "U5b2c2 Group A" (defined by 16249C) with ancestry in: Scotland, Sweden, Ireland, North Ireland and England. This "Group A" also appears to be quite old with an average of 2.2 extra mutations in addition to the mutation at 16249.
Behar et al. estimate U5b2c to be about 13,000 years old, so there is a very long history of U5b2c in Europe before the people in La Braņa 7000 years ago. The simplest story would be an Iberian ice age refuge followed by a very early expansion through Spain to England and Ireland. But that migration could have happened very long ago, perhaps with the first people to repopulate England and Ireland after the glacial maximum. The very old age estimates for U5b2c and its present distribution in Ireland, the UK, Sweden and Germany could leave open the possibility of other migration routes for early U5b2c to arrive in England and Ireland. It could even be possible that the U5b2c1 La Brana mtDNA arrived in Spain from Ireland or the UK. Not that I think this is likely, but I do think we need to consider the possibility of very complex migrations over a period of many thousands of years.
Kudos to the authors for doing the extra work on the full sequence - it would be great if other researchers would revisit their previously published HVR test results of ancient remains.
The sample appears to be U5b2c1 with no additional mutations reported in Table S2. We have 5 FMS test results in the U5 project for U5b2c1 and 1 partial result from Hernstadt. One person in the project has ancestry in Spain and also has no extra mutations, i.e., this person is an exact match to the Mesolithic La Brana sample. Two U5b2c1 people have ancestry in Ireland, and one has ancestry in Germany. They have between 1 to 5 extra mutations for an average of 2.17 and age estimate of 5700 years (compared to Berhar's estimate of 4200 years). Both estimates are younger than the remains dated to 7,000 years old. However, the age estimates are based on a small sample size and have large uncertainty. The FMS test result is very useful for an independent estimate of the age of U5b2c1, and it confirms a very old date for this group and also confirms that it was present in Europe during the late Mesolithic.
For comparison with other U5b2c in the FTDNA U5 project, we have one U5b2c* with ancestry in Ireland, we have two U5b2c2 with ancestry in Ireland and and 1 in Scotland. We also have 5 people in "U5b2c2 Group A" (defined by 16249C) with ancestry in: Scotland, Sweden, Ireland, North Ireland and England. This "Group A" also appears to be quite old with an average of 2.2 extra mutations in addition to the mutation at 16249.
Behar et al. estimate U5b2c to be about 13,000 years old, so there is a very long history of U5b2c in Europe before the people in La Braņa 7000 years ago. The simplest story would be an Iberian ice age refuge followed by a very early expansion through Spain to England and Ireland. But that migration could have happened very long ago, perhaps with the first people to repopulate England and Ireland after the glacial maximum. The very old age estimates for U5b2c and its present distribution in Ireland, the UK, Sweden and Germany could leave open the possibility of other migration routes for early U5b2c to arrive in England and Ireland. It could even be possible that the U5b2c1 La Brana mtDNA arrived in Spain from Ireland or the UK. Not that I think this is likely, but I do think we need to consider the possibility of very complex migrations over a period of many thousands of years.
Kudos to the authors for doing the extra work on the full sequence - it would be great if other researchers would revisit their previously published HVR test results of ancient remains.