adventures in dna

Taking part in National Geographic's Genographic Project has led me down some interesting paths, deep into mists of time. The Y-chromosome test traces your paternal lineage (father's father's father ....). The farthest I have been able to trace this is to Antonio Petrone, who was born in about 1795 in Acri, Italy. Acri is a town in the hills north of Cosenza in the northern part of Calabria. I honestly don't know much about the place. When I went to visit Italy in 2009, I wanted to visit, but because buses in southern Italy stop running after noon, it was basically impossible.

My Genographic result showed R1b1a2. As Wikipedia informs me, this is found mostly in the western part of Europe. The frequency is about 71 percent in Scotland, 70 percent in Spain and 60 percent in France. In parts of the rest of north and western England, Spain, Portugal, Wales and Ireland, it is as high as 90 percent; and in parts of north-western Ireland it reaches 98 percent. But in Calabria its frequency is quite low.

So this was perplexing. I ordered a Deep Clade Test, which tests for additional markers. I was negative for every marker tested except for one called P-312. This was significant because I tested negative for markers associated with certain populations: for instance, I tested negative for U152 and U106 which are associated with Germanic populations, including those in northern Italy. I tested negative for markers associated with the Irish and Scottish. My haplotype, it seems, is found mostly in "Iberia" (Spain and Portugal) and southern France. The locus seems to be somewhere in the Pyrenees. When I compared against others in the database, I came up with a list of people from northern Spain and Portugal, even some from the Azores and Canary Islands.

According to my grandfather, the Petrones came from Genoa. He didn't explain how they got to Calabria. But, here, have a look at what we are talking about.

There are several theories here: a) My forefathers passed through Calabria on the way to Iberia, leaving some "genetics" behind; b) My grandfather was right, and the family came from Genoa, perhaps arriving with the silk trade in the 16th-17th centuries, it is conceivable that people with this haplotype moved from southern France into northwestern Italy, Genoa is the first city over the border; or c) We are the product of some other historical event. Acri was ruled for a time by the Aragonese in the 15th century -- Aragon is a province in northern Spain, near the "epicenter" of this haplotype (where it is found in its highest frequency).

Honestly, there is no real way to figure this out. But, still, it's been educational and interesting.

UPDATE: There are seven other individuals in the Italy DNA Project that had the same results as me. Five provided their ancestors place of origin, specifically: Giusvalla, Grosseto, Savona, Potenza, and Perledo. I have marked these places and Acri and Genoa on the map below: