Genetic “Adam”

History of Haplogroup G

Spencer Wells, in his book, The Journey of Man—A Genetic Odyssey, describes the history of our Y-chromosome. The following is excerpted from Well’s book.

Genetic “Adam” Males all over the world have a set of markers, particular letters in the four-letter genetic alphabet, on their Y-chromosomes. 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. Actually, this date is rather uncertain since the 95% confidence interval is 40,000 to 140,000 years ago. Other data suggest that the date was probably a little older than 60,000 years ago, perhaps about 100,000 years ago. At that time, a mutation arose, which is now carried by every male on the planet. This man has been dubbed “Genetic Adam,” though this is a misnomer since he was certainly not the first male modern human. His father was undoubtedly fully as human as he was. The “silent” nature of mutations in non-functional regions of the Y-chromosome means that none of “Adam’s” contemporaries would have thought that there was anything out of the ordinary about him—indeed there probably wasn’t. There were also many other males living at the same time, but they did not carry the same mutation and none of the male lines from them survived down to the present.

Genetic Adam lived in Africa, probably on the plains of East Africa. He may have resembled the Han people who live in southern Africa today, though earlier they had lived over a wide area of eastern and southern Africa.

M94 ”Adam's" descendant identified by the mutation M94, which we Haplogroup G folk carry, lived on the plains of East Africa some 75,000 years ago. He is the ancestor of the overwhelming majority of males today because it is his progeny who "founded" all the Haplogroups B through R. Only Haplogroup A, which until fairly recently was confined to sub-Saharan Africa, does not carry M94. Everyone else is descended from M94 and carries the M94 mutation. Many of his descendants lived along the northeast African coasts.

M168 "M94's" descendant M168 lived about 60,000 years ago, perhaps in the area of today's Ethiopia. He too is our ancestor and we carry his M168 mutation. His descendants make up Haplogroups C-R. It is believed that increasing ice in the far north dried up the African climate to the extent that at least two different groups of M168's descendants left Africa in search of adequate food supplies, or perhaps just seeking new lands. Everyone outside of Africa, and quite a few people still in Africa, descend from M168. The first wave of his descendants left Africa close to 60,000 years ago and are believed to have followed the southern coastline of Asia eastward. Sea level at the time was as much as 400 feet lower than it is now. They and their descendants ended up in Southeast Asia, Australia, south China, and the Pacific Islands. A few even joined their (by then) distant cousins in North America some 10,000 years ago.

A second wave of M168's descendants went north and east out of the Sahara area (forced out in a period of drying) through Egypt into the Middle East. The ancestors of future Haplogroup G were among them.

M89 M168's descendant M89 lived about 45,000 years ago probably in modern-day Iraq. He was the founder of macro-haplogroup F. His descendants include all members of Haplogroups G-R. That means that he is the ancestor of virtually everyone in Europe and the Middle East, and of the vast majority of Asians and Native Americans.

A large group of M89's descendants moved up into central Asia above the Caspian Sea. It was very cold there near the edge of the great northern ice pack. Life was harsh but food was plentiful. Vast herds of big game thronged the tundra and the grasslands south of the ice pack A new mutation arose here, M9, that founded a new Haplogroup K, the "father" of the Eurasian Haplogroups L-R, whose descentants spread over most of Europe, Asia and the Americas. Half of Europeans today belong to this haplogroup, but our Haplogroup G Y-chromosomes are only cousins of these. Many of M89's descendants stayed in or near the Middle East and perhaps some even returned to northeastern Africa. New mutations among them gave rise to the Haplogroups G-J.

M201—Founder of Haplogroup G The first guy to have the M201 mutation which distinguishes our Haplogroup G is thought to have lived about 30,000 years ago along the eastern edge of the Middle East, perhaps as far east as the Himalayan foothills in Pakistan or India. He has had relatively few descendants. Some of them went east on into Southeast Asia, south China and the Pacific Islands, but most moved back into the Middle East. Then about 10,000 years ago 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 Cresent” 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 must have displaced or eliminated the hunter-gatherers of Europe. However the DNA studies have shown that the spread of agriculture did involve the movement of some people into Europe who had not been there before, but largely the spread of farming was through the adoption of the practice by the existing Europeans. An hypothesis which is growing stronger recently is that these same people at the same time may have introduced the Indo-European language into north India, the mid-East and Europe. Indo-European is the parent language for Greek, Latin, Sanskrit, Germanic and hence of most of the other languages of the mid-east, north India and Europe.

To be more specific about where Gs are to be found today: those that went east have very small numbers of living male-line descendant members in China, Indonesia, Taiwan, the Philippines, and the Polynesian Islands of the Pacific. 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, 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%.

Our Cousins, M52, M170, 12f2.1 The mutations M52, M170, and 12f2.1 gave rise to Haplogroups H, I, and J, which are “brother” haplogroups of G. H is largely confined to the Indian subcontinent. I spread up through central Europe and into Scandinavia, where it is well represented today. J is very common in the Middle East, where many Jews, Arabs, and others belong to it. These three haplogroups probably arose between 20,000 and 30,000 years ago. Haplogroups J2 and E3b, along with G, came to Europe primarily during the spread of agriculture.