Haplogroup J is considered to be one of the seven founding European haplogroups (Sykes: "Seven Daughters of Eve"), and is defined by a mutation which occurred ~10 000 years ago.
The maternal equivalent of Y-Chromosome Haplogorup 9 and 21, J was presumably brought to Europe during the Neolithic period during the influx of agriculture.
However, unlike what is seen with Y-Chromosome Neolithic markers. , the frequency of J is considerably higher in Northern Europe than in the Mediterranean periphery, as one can observe:
Maternal Haplogroup J
Bulgaria/Turkey 14.7%
Western Isles/Isles of Skye 14.64%
England/Wales 14.45%
Scotland 14.44%
Iceland 14.31%
Ireland 14.06%
Scandinavia 10.24%
France/Italy 6.04%
Spain/Portugal 5.96%
Paternal Haplogroup 9
Turkey 33%
Italy 20%
Bulgaria 12%
Ireland 1%
E. Anglia 1%
W.Scotland 0%
Cornwall 0%
Iceland 0%
Gotland 0%
Paternal Haplogroup 21
Greece 28%
Bulgaria 17%
Italy 13%
Turkey 10%
Spain 10%
France 8%
Cornwall 0%
Scotland 0%
Gotland 0%
As you can see, there is little correlation between J and its Y-Chromosome counterpart(s).
However, J can be broken down into several sub-clusters, including J, J1 and its respective sub-branches, as well as J2. Presumably, J is the oldest mutation of the three, with J1 being newer, and J2 the newest.
Frequency of J (*)
Ireland 11.72 %
England/Wales 10.72%
Scotland 8.64%
Iceland 6.85%
Turkey/Bulgaria 5.88%
Spain/Portugal 3.69%
France/Italy 2.42%
Frequency of J2
Bulgaria/Turkey 2.94%
France/Italy 2.42%
Western Isles/Isle of Skye 1.63%*
Iceland 1.28%*
Ireland .78%
England/Wales .23%
Austria/Switzerland 0%
Frequency of J1(various sub-clades not included)
Bulgaria/Turkey 4.90%
Austria/Switzerland 1.60%
Western Isles/Isle of Skye 1.22%*
Scotland .56%
England/Wales .47%
Ireland 0
*note: Figures may be indicitive of a small founder population.
As one can observe, only the "J" subgrouping, the oldest and most genuinely "Neolithic" haplogroup is only truly widespread in Northern Europe.
Other clades, which probably represent more recent gene flow, are more common to the Mediterranean and Near East.
However, the question remains as to why J, even when analyzed as a specific sub-clade, is found at greater frequencies in isolated areas of North-Western Europe than in Central Europe where most of the Agricultural influx centered.
Could J perhaps provide an advantage to the cold weather of Northern Europe?
"Positive selection is also a possible influence. The presence of mtDNA haplogroup J in our sample, and elsewhere in Northern Europe shows that its frequency in Norway is even higher than in those areas from where it probably arrived. It would be intriguing, although very speculative, to hypothesise that the climate of Northern Europe may have played a selective pressure where the uncoupling of oxidative phosphorylation and the consequent higher production of heat in J individuals may have led to an advantage, as previously suggested for the European groups during the glaciations. (Passarino et al. 2002)"
http://www.geocities.com/refuting_rm/1.html
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Originally Posted by Dr. Solar Wolff
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