This mighty progenitor was not a celebrated expert in the amorous arts like Casanova. Instead -- and this might say something about human nature that we'd rather not know -- he owed his lineage's staggering reproductive success to his being perhaps history's greatest fighter.
The 23 co-authors of a paper published electronically by the American Journal of Human Genetics examined the Y-chromosomes of 2,123 men from across Asia. The Y chromosome is found only in men and is passed down from father to son to grandson and so on, just as a surname is passed down "patrilineally." Men who share a unique last name are likely to share a mutual forefather, and so are men who share unique bits of DNA coding in their Y-chromosomes.
It's important to keep in mind that this Y-chromosome analysis tracks only the purely paternal lineage through the ever-branching genealogical thickets. Possibly the best known example of the male line is the "Begats" that open the Gospel According to St. Matthew: "Abraham begat Isaac; and Isaac begat Jacob" and so forth down through King David and his son King Solomon and on to Jesus Christ.
In over 90 percent of the Asian men tested, the Y-chromosomes were quite diverse, indicating a multiplicity of paternal-line ancestors in their highly varied family trees. In striking contrast, 8 percent had Y-chromosomes that were virtually identical, indicating a common recent forefather.
This individual man's Y-chromosome is today found in an estimated 16 million of his male line progeny in a vast swath of Asia from Manchuria near the Sea of Japan to Uzbekistan and Afghanistan in Central Asia. That's one of every 200 males on Earth today.
Of course, the scientists didn't use terms like "greatest lover;" but, for academic authors, they did seem rather excited, calling their finding "novel," "striking," and "unique."
So, who was this potent patriarch?
Oxford biochemist Chris Tyler-Smith, one of the co-authors of the new report "The Genetic Legacy of the Mongols," told United Press International, "We are pretty sure that this man lived in Mongolia or nearby, at about a thousand years ago, with an error of plus or minus a few hundred years."
Early in the last millennium, the population of the world was, speaking very roughly, 1/20 as large as it is today. Therefore, the average man alive then has 20 descendants alive today in his direct male line. In contrast, with about 16 million direct descendants, this one mega-ancestor was something like 800,000 times more successful than the average.
The co-authors wrote, "Within the last 1,000 years in this part of the world, these conditions are met by Genghis Khan (c. 1162-1227) and his male relatives. He established the largest land empire in history and often slaughtered the conquered populations, and he and his close male relatives had many children."
His original name was Temujin, but he took the title of Genghis Khan or "Universal Ruler" when he united the fractious Mongolian tribes in 1206. He and his pony-mounted archers then set out on a whirlwind of conquest and destruction. His armies ravished northern China, Samarkand and the other fabled Central Asian cities of the Silk Road, and much of far-off Russia. This earned him such monikers as the Mighty Manslayer, the Scourge of God, the Master of Thrones and Crowns, and the Perfect Warrior.
His sons and grandsons extended the Mongol empire to southern China. In Iraq, they demolished the great city of Baghdad in 1258, profoundly setting back Islamic civilization. The Mongols devastated Poland and reached the outskirts of Vienna.
Genghis Khan had six Mongolian wives and later married many daughters of foreign kings who prudently submitted to his rule. (Indeed, "Khan" is a common surname in much of Asia, although not all who bear the name are in his patriarchal lineage.) He also raped many women whose men folk had foolishly thought they could withstand his fury.
Tyler-Smith noted, "In 'The Secret History of the Mongols,' an extraordinary and unique contemporary or near-contemporary document, Genghis Khan's subordinates are represented as explicitly promising him the pick of captured women and horses."
Historian George Vernadsky wrote, "The plundering of enemy territories could only begin when Genghis Khan or one of his generals gave permission. Once it had started the commander and the common soldier had equal rights, except that beautiful young women had to be handed over to Genghis Khan."
Once, his lieutenants were idly debating what was the greatest enjoyment that life afforded. The consensus was leaning toward the sport of falconry, when their leader decisively interjected his own deeply felt view: "The greatest pleasure is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters."
Gregory M. Cochran, a physicist turned evolutionary theorist who is joining the faculty of the University of Utah's prominent anthropology department, was impressed with the study, telling UPI, "This is the coolest thing; the reality they've uncovered is so lurid it's like a science fiction story. I guess you could say that Genghis Khan made out like a bandit."
"More seriously, this disproves the theory of history promoted by Marx and Tolstoy that says only social forces matter, not individuals," Cochran claimed. "This shows that one man can make a difference."
Tyler-Smith stressed that the 16 million male descendants are just those who belong to this one patriarchal lineage, not the much greater number who are descended in any fashion from Genghis Khan. "Virtually everybody today who lives near the Asian steppe must have Genghis Khan somewhere in his or her family tree," speculated Cochran.
At present, however, no one has estimated with confidence what percentage of the world's "autosomal" DNA is descended from Genghis Khan. (That's the main body of the genome, which is inherited by both sons and daughters and recombines in random new patterns with each conception. It is more difficult than the Y-chromosome for population geneticists to work with in these kind of massive paternity tests.)
The maximum possible is 0.25 percent of all humans' ancestry, which would be a jaw-dropping figure, but it's probably significantly less because, being a patrilineal culture, the social advantages to being a descendant of Genghis Khan accrued primarily to those in the pure male line.
Tyler-Smith said, "This figure depends a lot on the reproductive success of his descendants who were not recognized as patrilineal relatives. At the maximum, there could now be millions of people (men and women) carrying each of Genghis Khan's autosomal genes. My guess, however, is that the reproductive advantage was focused on the Y (or male) lineage, and so the number carrying each autosomal gene will be much less than this. But it is an empirical question, and further work in these populations could provide the answer."
To be technical, the "most recent common ancestor" of all these modern Asian men was probably not Genghis Khan himself, but instead a recent patrilineal ancestor of his, such as a paternal grandfather. Tyler-Smith said, "We don't think that Genghis Khan was the common ancestor, because our best estimate of the time when the common ancestor lived was a few generations before he was born."
It's likely that some brothers and male cousins of Genghis Khan who shared his Y chromosome enjoyed heightened reproductive success in his enormous wake, rather like how it is said that some of the sex appeal of the rock band Led Zeppelin rubbed off on its lucky roadies.
Still, there's no question that Genghis Khan was the main man in his family. Cochran said, "I don't think Genghis Khan shared much."
Cochran pointed out, "In Genghis Khan's time, promiscuity wasn't as dangerous because syphilis wasn't known in Eurasia until 1493 (a date that suggests it was brought back from America by Columbus' sailors)."
Was Genghis Khan the most successful patriarch of all time? No scientist has yet noticed a similar size genetic footprint made by another historical figure, but population genetics is still a growing field. Thus, it's possible that some other man will emerge to rival the famed Mongolian.
Cochran speculated, "You'd need several factors to contend for the record. You'd need to conquer a big empire. You'd need a place where harems are common. So, forget Europe. Charlemagne couldn't have had the same impact. You'd have to be able to organize a big, long-lasting state, so medieval Africa is an unlikely setting. Maybe the founder of a long-lived Chinese dynasty would be in the running. Or the founder of a polygamous religion."
According to the Guinness Book of World Records, the 18th century Moroccan ruler Moulay Ismail the Bloodthirsty fathered 888 children out of his harem of 500 women. (Dorothy Einon, a psychologist at University College London, has cast doubt on the feasibility of one man achieving this suspiciously symbolic-looking number, however.) The fertility of that despot's heirs, though, is not known.
While the number of Genghis Khan's children is unknown, the reproductive success of his male-line descendants, known to history as "the Golden Family," is not in doubt, especially those descended from the four sons of Bortei, Genghis Khan's impressive first wife. The conqueror established a social legacy that benefited his sons' sons unto the seventh generation and even beyond.
For example, his famous grandson Kublai Khan, the emperor of China, had 22 legitimate sons by his four wives, but also had numerous concubines. Kublai Khan's underling, the famed Italian traveler Marco Polo, wrote that each year the emperor took 30 additional virgins to be his concubines from a province renown for the beauty of its women.
While the Mongolian Yuan dynasty in China was overthrown in 1368, Genghis Khan's male-line descendents clung to power elsewhere. For instance, they were not driven from Russia until 1502.
Incredibly, as late as the early 20th century, three-quarters of a millennium after Genghis Khan's birth, the aristocracy of Mongolia, which was 6 percent of the population, consisted of his patrilineal descendants. Today, among the Hazaras, an outlying group of Mongolian-looking people in Pakistan and Afghanistan, many men can recite their genealogies going back about 34 generations to Genghis Khan.
How certain is it that Genghis Khan was the driving force in the dispersion of this extraordinary Y-chromosome? Tyler-Smith said, "The alternative explanation would be that, despite the historically-recorded activities of Genghis Khan, his Y-chromosome did not spread, but that of an unknown man living in the same place at the same time did, to an unprecedented extent." Perhaps showing the English penchant for understatement, the Oxford scientist concluded, "This seems less likely."
"Of course," Tyler-Smith continued, "the ideal evidence would be a direct analysis of DNA from his remains. Unfortunately, the location of his tomb is unknown." That's because Genghis Khan wanted it kept secret. According to the annals, 40 "moonlike" virgins and 40 horses were sacrificed at his funeral for his posthumous enjoyment. Then, each of the 2,000 people who attended his funeral was massacred by 800 soldiers, who in turn were killed to preserve the secret of his tomb's locale.
A team of archaeologists funded by Chicago lawyer and Genghis Khan devotee Maury Kravitz is currently searching in northeastern Mongolia, where Temujin was born. They have found some promising sites for digging.
Kravitz has pointed out that his hero was one of the biggest looters in history, yet much of his booty seems to be missing. So, the lawyer argues, perhaps the conqueror's treasure was buried alongside him. Cochran responded, "If true, this could make King Tut's tomb look like a Wal-Mart."
"The really interesting find, however, would be Genghis Khan's DNA," Cochran continued. He suggested that among Inner Mongolians and the Hazaras, on whom Genghis Khan left such a genetic imprint that his Y-chromosome is found in at least a quarter of the men, there must have been a lot of inbreeding among his descendants. Yet, judging from their Darwinian success at surviving and reproducing in large numbers, that might imply that Genghis Khan had very few bad recessive genes of the kind that often damage the health of the offspring of close relations.
"Between that and the fact that he conquered most of the world, it's fair to wonder if he was a little genetically unusual," mused Cochran. "Of course, if you found his corpse and could extract his DNA, eventually, at some point in the future, you'd be able to clone 'the Perfect Warrior.' Do you think the Department of Defense would want an army of Genghis Khans?"