What is Genetic Genealogy?
Y-DNA passes from father to son almost unaltered for long periods of time. It determines whether a child will be male or female. Humans have 23 paired chromosomes (bundles of tightly coiled DNA), 22 pairs of autosomes and one pair of sex chromosomes. A single chromosome of each pair is passed from each parent to child.
A test of the Y-DNA measures a short sequence on the Y chromosome. The cell sample is collected using a swab in the mouth rubbed on the inside of the cheek. The Y chromosome is the only chromosome unaffected by the mother's genes. It has definable segments of DNA with known genetic characteristics. These segments are known as markers. These markers occur at identifiable physical locations on a chromosome known as loci. Each marker is designated by an internationally used number known as a DYS number.
Although there are several types of markers used in DNA studies, the Y-Chromosome test uses only one type. The marker used is called a STR test (short tandem repeat test). STR's are short sequences of DNA (ususally 2, 3, 4, or 5 base pairs long), that are repeated numerous times in a head-tail manner. These repeats are referred to as alleles. The variation of the number of repeats of each marker enables discrimination between individuals. Because mutations in the allele value occur very slowly over time, one should see the same allele value for a male and his great-grandfather, for example.
Although more in-depth DNA tests can be run, we requested a basic 12-marker STR test (short tandem repeat test).
The test results above represent the actual allele values for 12 locations on the Cerf Y chromosome.
Predicted Haplogroup
If all alleles for the 12 locations match another person exactly, then they share the same haplotype. If the numbers are off by one position from another person in one location, then they are considered in the same haplogroup. Haplogroups are branches in the human genetic tree. They are tied to deep ancestry as far away as tens of thousands of years. Haplogroups are predicted based on the 12-marker results and using databases of individuals who have had their haplogroup confirmed through more extensive (and more expensive) DNA testing.
The predicted haplogroup for the Cerf family is E1b1b1, also known as E-M35.1.
Migration Map
The ancestors of present day non-African people left their ancestral homeland roughly 60,000 to 70,000 years ago. Haplogroup E1b1b, which is a larger group that Haplogroup E1b1b1 falls into, represents the last direct major migration from Africa into Europe. Using DNA samples from a quarter of a million volunteers (as of 2008) in different continents, scientists have completed a massive study that created a migration map for mankind. The migration of the E1b1b haplogroup indicates migration from central Africa to East Africa and across Africa's northern coast. A smaller portion of people in this haplogroup migrated from East Africa to the Middle East and then into Europe from the Mediterranean (not shown on the map).
The final common ancestor in the E1b1b1 haplogroup, the man who's genetic mutation gave rise to this marker, was born around 20,000 years ago in the Middle East. On the European continent, this haplogroup has the highest present-day concentration in northwest Greece, Albania and Kosovo, and then fading around the Balkans, the west of Greece and western Turkey. Outside Europe, it is found in most of the Middle East, northern and eastern Africa, especially in Morocco, Libya, Egypt, Yemen, Somalia, Ethiopia, and South Africa. This E1b1b1 haplogroup was the group that migrated from East Africa to Europe via the Middle East.
Genetic Matches
Only two persons who have undergone genetic testing match all 12 allele markers perfectly. They both indicate their oldest known ancestor in the male lineage came from Switzerland. The last names of those oldest known ancestors were Blatter and Shuler. What does this mean? Statistically, it means that there is a 50 percent probability that the Most Recent Common Ancestor lived no longer ago than seven generations. This is only an estimate, and the actual generation of the shared ancestor could be nearer or further than predicted. There is a 90 percent probability that the Most Recent Common Ancestor lived no longer ago than 23 generations. And there is a 95 percent probability that the Most Recent Ancestor lived no longer ago than 29 generations. Scientists use 25 years as the length of a typical generation prior to the Dark Ages and 25 to 30 years per generation for the period thereafter.
There are currently 29 persons who have undergone genetic testing showing a genetic distance of one (one allele out of 12 is different by only one number of repeats). And there are 148 matches with a genetic distance of two, still within the range of most well-established surname lineages in Western Europe. Even with a genetic distance of four between two people, they are still "probably related."
The countries of the oldest known ancestor in the male lineage with a genetic distance of one include Hungary, England, Scotland, USA (South Carolina and Virginia), Turkey, Canada (Ontario), Austria, Switzerland, Saudi Arabia, Netherlands, and Egypt. The countries of the oldest known ancestor in the male lineage with a genetic distance of two include Germany, Czechoslovakia, Wales, Canada, England, Russia, Ireland, Saudi Arabia, Poland, USA (Tennessee, North Carolina, Kentucky, New York, New Jersey, Michigan, and Indiana), South Sandwich Islands, Ukraine, Belarus, Austria, Chile, Latvia, Spain, India, Italy, Mexico, Switzerland, Portugal, France, Romania, Netherlands, Lebanon, Hungary, and Egypt. Remember, our sample is only composed of those people who have had genetic testing done.
What's Ahead in the Future
Family Tree DNA plans to post genetic information of famous persons in history so that researchers will be able to compare themselves. Some famous persons supposedly in the E1b1b1 or E1b1b haplogroups, but with varying genetic distance, are Henry Rothschild, Pope Paul V, the artist Caravaggio, Napoleon Bonaparte, Albert Einstein, the Wright Brothers, President Lyndon B. Johnson, and even Adolph Hitler.
The Genographic Project at National Geographic hopes to answer some questions about mankind. "How many migrations out of Africa were there? What role did the Silk Road, with its caravans and bazaars, play in dispersing genetic lineages across Eurasia? What can our genes tell us about the origins of languages? How did the great empires of history leave their genetic marks on our DNA? And if we all share such a recent common ancestry, why do we all look so different?"
References:
Family Tree DNA, familytreedna.com.
Genographic Project at National Geographic, genographic.nationalgeographic.com.
McKie, Robin, "The Incredible Journey Taken by Our Genes," The Observer, August 30, 2008, http://www.guardian.co.uk/science/2008/aug/31/genetics?INTCMP=SRCH.
Ysearch.org.
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