Human geography is mapped in the genes
The genes of a European person can be enough to pinpoint their ancestry down to their home country, claim two new studies.
By reading single-letter DNA differences in the genomes of thousands of Europeans, researchers can tell a Finn from a Dane and a German from a Brit. In fact a visual genetic map mirrors the geopolitical map of the continent, right down to Italy's boot.
"It tells us that geography matters," says John Novembre, a population geneticist at the University of California, Los Angeles, who led one of the studies. Despite language, immigration and intermarriage, genetic differences between Europeans are almost entirely related to where they were born.
This, however, does not mean that the citizens of each European nation represent miniature races. "The genetic diversity in Europe is very low. There isn't really much," says Manfred Kayser, a geneticist at Erasmus University Rotterdam in the Netherlands, who led the other study.
Though the teams worked independently, they used some of the same DNA samples, which were gathered by the pharmaceutical company GlaxoSmithKline to help hunt for genes linked to drug side effects. The researchers recorded the results alongside the country of origin for each subject as well as that of their parents and grandparents when possible.
For each subject, the researchers decoded half a million SNPs. However, to get an overall assessment of the difference between any two genomes, the researchers used a mathematical trick that scrunched the hundreds of thousands of SNPs into two coordinates, with each person's genome represented by a point. The greater the distance between two points, the greater the difference in their genomes.
When both teams plotted thousands of genomes on a single graph along with their country of origin, a striking map of Europe emerged. Spanish and Portuguese genomes clustered "south-west" of French genomes, while Italian genomes jutted "south-east" of Swiss.
These cardinal directions are artificial, but the spatial relationships between genomes are not. In general, the closer together two people live, the more similar their DNA. The same is known to be true of animals .
The map was so accurate that when Novembre's team placed a geopolitical map over their genetic "map", half of the genomes landed within 310 kilometres of their country of origin, while 90% fell within 700 km.
Both teams found that southern Europeans boast more overall genetic diversity than Scandinavians, British and Irish.
"That makes perfect sense with the major migration waves that went into Europe," says Kayser, noting Homo sapien's European debut 35,000 years ago, post-ice age expansions 20,000 years ago, and movements propelled by the advent of farming 10,000 years ago. In each case, members of established southern populations struck north.
"A pattern in which genes mirror geography is essentially what you would expect from a history in which people moved slowly and mated mainly with their close neighbours," says Noah Rosenberg, a geneticist at the University of Michigan in Ann Arbor.
Source: NewScientist
Hi SAM,
I thought this might be of interest.
Cariños, Evelyn
commentby SAMocanos | 6 September 2008 at 01:41
Kool, huh?
commentby Bro | 6 September 2008 at 08:26
I would be interested in seeing an online map of the reported findings to see how it compares with the one available from National Geographic at https://www3.national geographic.com/genographic/atlas.html
I have included all my family's YDNA results on my tree, including my personal ones. I have tried to upload my tree to Geneanet, but I keep getting bounced off (likely due to my tree's size). Ken
commentby kenrob39 | 6 September 2008 at 20:20
Records show our family living in Nth Lincolnshire U K since early 15th century as a christian family at the same time a Jewish family of the same name have lived in eastern Europe.DNA would establish if there was a relationship. How could I find this?
commentby jack | 10 September 2008 at 01:22
My female line DNA test tracks my ancestors through back through Colonial Virginia into Wales and England, and through Europe. My female ancestor came from North Africa through the Iberian Peninsula about 45, 000 years ago. She settled in the Basque Region of Spain before moving through Europe, and into the Americas. Prior to taking the DNA test I had proved lineage to the LLewelyns who are of Welsh descent. It was helpful to have my DNA cousins contact me with their research.
commentby alani2 | 15 September 2008 at 05:06