Once a particular marker appears by mutation in a man, all of his descendants will also carry that marker. If we compile information on a large set of markers and project them back in time using computer algorithms, we find that the trail of mutations coalesces in a single y chromosome whose owner lived, according to the genetic dating, some 60,000 years ago (~2,400 generations). The date is not certain, and could have been anywhere between 40,000 and 140,000 years ago. At that time, a mutation arose, which is now carried by every male on the planet.
This man who carried this mutation has been dubbed “Genetic Adam”.
M201 — Founder of Haplogroup G
About 10,000 years ago (~400 generations) things began to change for the members of the four Haplogroups G-J. Prior to this time all humans were hunter-gatherers. The people of what was known as the Fertile Crescent developed agriculture and the world would never be the same again. Population could expand rapidly and farmers began moving out of the Middle East, through the islands and along the shores of the Mediterranean, through Turkey into the Balkans and the Caucasus Mountains.
It was once thought that the advancing farmers displaced or eliminated the hunter-gatherers of Europe. However the DNA studies have shown that the spread of agriculture involved the movement of some people into Europe who had not been there before (Haplogroups J2 and E3b), but the farming spread largely by cultural diffusion to existing Europeans. One hypothesis, gaining ground recently, is that these same people introduced the Indo-European language into northern India, the mid-East and Europe. Indo-European is the parent language for Greek, Latin, Sanskrit and German, and hence of most of the other languages of the Middle East, northern India and Europe. There have been many attempts to identify the original Indo-European culture and homeland. It is currently thought to have been the Sredy Stog culture in what is now eastern Ukraine.
The descendants of M201 who went east have very small numbers of living male-line descendant members in China, Indonesia, Taiwan, the Philippines and the Polynesian Islands.Those that went north have small numbers of living male-line descendant G-folk in Syria (Arab), Russia (Adygeans), Uzbekistan (Tartars and Karakalpaks), Mongolia, and western China Uygurs).Those that went west and north live today in Italy, Sicily, Hungary, Austria, Germany, France, Norway and Sweden. In the Republic of Georgia (Caucasus Mountains, south of Russia and north of Turkey ) members of G make up as much as 30% of the population. There are 14% on the island of Sardinia, 10% in north central Italy, 8% in northern Spain, almost 7% in Turkey, and lesser percentages in the Czech Republic, Slovakia, the Ukraine, Lebanon, Greece, Hungary, Albania, Croatia, and Ethiopia. G is still represented in the Middle East — some of these are Arab, some are Jews, many are neither. Across northwestern Europe, G haplotypes occur at a low frequency, 1-3%.
M201 has relatively few descendants. Only about 1-2% of modern-day people of European ancestry are in Haplogroup G, with a gradient from southeast (most common) to northwest (least common). Most geneticists currently believe that when Haplogroup G, J and E3b are found in Europe, they are markers for the spread of farmers from the Middle East into Europe 6,000-8,000 years ago. Worldwide, Haplogroup G is most common in the Caucasus region, especially the Republic of Georgia where the prevalence approaches 30%. It is also fairly common in Turkey (10%).
The mutations M52, M170, and 12f2.1 gave rise to Haplogroups H, I, and J, which are brother haplogroups of G. Haplogroup H is largely confined to the Indian subcontinent. Haplogroup I spread up through central Europe and into Scandinavia, where it is well represented today. Haplogroup J is very common in the Middle East, where many Jews, Arabs, and others belong to it. These three haplogroups probably arose between 20 and 30,000 years ago.
The G2 branch of Haplogroup G is defined by a mutation at P287. This mutation seems to have originated in Anatolia (modern Turkey), but the date is uncertain. It is found most often in the Caucasus and Middle East. One distribution map of this haplogroup shows a concentration in central Italy, diffusing north into the Swiss Alps.
G2 has two subgroups, G2a and G2b, defined by mutations at P15 and M286, respectively.
This subgroup of G2 is defined by a mutation at P303. Ray Banks says, “The latest thinking is that G2a3b persons originated in the general area of western Iran sometime perhaps around 500 BC.” (Banks Families and other closely related persons within Haplgroup G2a3b). However, this group includes the Rangaswamy family, a high-caste Indian family, whose common ancestor with P303 and DYS=13 is estimated to have lived 3,000 years ago.
One of the — probably ancient — divisions within Haplogroup G2 is between those who have 13 repeats at DYS388, and those who have 12 repeats. Ray Banks estimates this mutation at 2500 years ago. Europeans are more likely to have 13, and Middle Eastern men are more likely to have 12. There are exceptions, however. Some Iranian men, those just south of the Caspian Sea, are more similar to men south of the Caucasus Mountains (Georgia, Armenia, Azerbaijan) than to other Iranians. In addition, there are many indications that some Iranians have a closer relationship to Welshmen, Englishmen, Swiss and southern Germans than to Turks, Russians and Ossetians. Such results suggest ancient migration patterns.
This subgroup of G2 is defined by mutations at S146 and S147 (also know as L42 and L43). All members of G2a3b2 have 13 repeats at DYS388, so this mutation must have been later, but it must have occurred almost immediately after, because the two mutations are approximately the same age.
Haplogroup G is a Middle Eastern Group. One of the striking things about it is how intertwined all of its subgroups are with Jews. Ray Banks has recently suggested that the spread of G2 in Europe could be explained by the spread of Jewish merchants, who are known to have settled heavily in Switzerland and Flanders, two areas with a high concentration of G2 in modern times. See Haplogroup G and Migration Patterns for more information.