The Invisible History of the Human Race

by Christine Kenneally

  Almost a thousand years later, in 2003, scientists sampled the DNA of many modern populations throughout the Asian region and found a Y chromosome with a distinct pattern of DNA that was almost entirely exclusive to sixteen groups. They believed the Y they had found must be Genghis Khan’s. The geographic distribution of the chromosome suggested that the Y started its spread from Mongolia, where the empire began. The biological pattern of the Y itself suggested that its progenitor must have lived around one thousand years ago, which Genghis Khan did. In addition, the way the Y was distributed in modern-day populations—from the Pacific all the way through Mongolia, on through central Asia, and ending with Uzbekistan—almost perfectly matched the boundaries of the ancient Mongolian empire.

  There was one exception to the match between the distribution of the modern-day Y and the demographics of the ancient empire: the Hazara people of Pakistan. According to the geneticists, the Hazaras have the Khan Y, yet they were the only group with that Y to live outside the region that had once been part of the official Mongol Empire. But it may be that the mismatch actually proves the rule, as the team later discovered that the Hazara have an oral-history tradition that asserts that they are descended from Khan himself.

  The scientists estimated that the Khan Y is probably carried by sixteen million men today, most of whom live in Asia. When Robinson received his startling call, it looked as if just one, the prodigal accountant, lived in Miami.

  Oxford Ancestors found the match between Robinson and Genghis Khan surprising enough that they called him. They told him he matched Genghis Khan’s Y on seven out of nine markers. Although markers mutate independently and change over time, there were enough of them in common to suspect it was a good match. How did Genghis Khan’s Y make it to the New World? One suggestion was that it had traveled via slaves from Asia to England and from there to the United States.

  The company sent Robinson a certificate that read: “This is to certify that Thomas R. Robinson carries a Y chromosome which shows him to be of probable direct descent from Genghis Khan, First Emperor of the Mongols.”

  They also asked Robinson if he minded if they announced the match publicly. He had no objections.

  • • •

  It wasn’t long before the curious connection between the Destroyer and the number cruncher was reported by the Times of London, the New York Times, the Miami Herald, and other newspapers. When the story hit, Robinson was on an Alaskan cruise with his wife, but the press were frantic to contact him. His in-box was bombarded, and his voicemail was full. News agencies flew photographers to find him when his ship called into port. Exciting offers were made, and one TV production company asked to fly him to Mongolia. The Mongolian ambassador to the United States extended an invitation to meet him in Washington. Robinson even got a call from a representative of a chain of Mongolian barbecue restaurants in Texas, who asked him if he would be their spokesperson. Not long after that, Robinson noticed that Oxford Ancestors was offering a new Khan-specific test on its Web site.

  As the offers flooded in, some concerned people also got in touch with Robinson. Most of them were genetic genealogists who explained to him that the match had been made on the basis of few markers. In order to confirm the connection, they advised him to get more and different markers checked.

  Robinson decided to get a second opinion, so he contacted Bennett Greenspan at Family Tree DNA. The company still had a sample of Robinson’s DNA from his earlier test. Greenspan rushed to redo the test and then ran a more powerful test. He determined that Robinson was not a relative of Genghis Khan. In fact, his Y chromosome was not even Mongolian, though it did probably come from central Asia. When he gave Robinson the news, he assured him that his results were private and that he wouldn’t tell anyone else about them without Robinson’s permission. But Robinson said, “No! You have to tell everyone.” So he did.

  All the Genghis Khan–related offers faded away, and Robinson happily got on with his life. He now works for a nonprofit company and regularly travels all over the world, although he hasn’t yet made it to Mongolia. He later heard that a Chinese journalist complained that he must have had the second Y chromosome test because he didn’t want people to think he was Asian. Robinson and his Asian American wife found this especially amusing.

  There is something undeniably compelling about the descendants of a historical figure. Consider the actor Anna Chancellor, the eighth great-niece of Jane Austen. It’s impossible not to imagine whether she looks like her great-aunt. What about Hitler’s nephews, allegedly still alive on Long Island, New York? What is life like for them? Or for Osama bin Laden’s children in exile in the United States? In the past decade newspapers have devoted many column inches to the descendants of Charles Darwin, a diverse bunch. One great-great-great-granddaughter, Laura Keynes (also a great-great-niece of economist John Maynard Keynes) converted to Catholicism and is now an apologist for the faith. One of Charles’s great-great-grandsons, Chris Darwin, who used to be called “the missing link” at school, gained notoriety for being part of a team that hosted the world’s highest dinner party (22,205 feet, on Mount Huascarán in Peru). Now he is an abseiling guide who lives in the Blue Mountains in Australia. In 2009 his sister spent time with a film crew tracing the journey of Darwin’s famous ship, the Beagle, to mark the 150th anniversary of the publication of On the Origin of Species. “Most of the direct descendants have had a pretty busy year,” Chris Darwin told a local newspaper at the time. Of the approximately one hundred living descendants of Darwin, one is now an acupuncturist, another is a novelist, one is a botanist who has expertise in the Galapagos tomato, one is an ecologist, one is a dancer, three have received knighthoods, and one works on the TV show Doctor Who.

  The tale of the accountant and the ancestral Mongol hordes was picked up everywhere in the media because it is, after all, a great story. The tale of the accountant and what turned out to be a non-Mongolian Y is important too. It underlines the fact that bringing together genetics and history involves some particularly tricky science, and because most of us are not scientists, there is some point at which we need to take people at their word—for whatever that is ultimately worth.

  It also reminds us that wherever compelling stories appear, commerce will likely be involved. Still, there is much to be learned about our history, and even if some of the most tantalizing possibilities are on the cutting—and less certain—edge, there is a strong scientific foundation for these questions.

  • • •

  It’s taken about one hundred years from first understanding the basics of human chromosomes to reach the point at which we’re making connections to long-lost ancestors through the centuries. Around the beginning of the twentieth century, scientists discovered that within the bubble of the nucleus that sits within the bubble of a human cell, men and women have twenty-three pairs of chromosomes. One chromosome in each pair comes from the mother and the other chromosome from the father.

  Men and women have the same chromosome pairs, with one exception: While both men and women have an X chromosome, women have a second one, but men only have one. In lieu of the second X, men have a Y. This is what makes them men.

  Given that only men have a Y, it follows that all men get their Y from their fathers. Recall that Ben Franklin discovered he was the son of a son of a son, going back five generations to Thomas Franklin of Acton, England. Ben would have had the same Y as Thomas. Ben’s son William, with whom he was traveling, would have had that Y too.

  For a long time scientists believed that the Y chromosome was the same for all men, but toward the end of the twentieth century, they discovered that men’s Y chromosomes differ in traceable ways. It became clear that if they looked at a group of Y chromosomes, the ways in which they were different formed a pattern. Most exciting of all, that pattern could be read like a historical record.

  What makes the Y unique among all chromosomes is that it is passed down from fathe
r to son as is. Normally, before they are passed down, the chromosomes in a pair are very lightly shuffled together. A chromosome may swap one or two small segments with its partner, undergoing a process of recombination. Unlike all the other chromosomes, the Y doesn’t go through the shuffling process, so the chromosome is handed down, again and again, from father to son. The Y’s partner chromosome is always an X from the mother, but the Y doesn’t mix its DNA with that of the X.

  For the purposes of genetic variation and the health of the species, chromosome shuffling is beneficial. It means that when we create a new child, and it gets one copy of each chromosome from a parent, those copies are a good mix of the grandparents’ DNA. But the Y has few functional genes and is small relative to the other chromosomes so its lack of recombination doesn’t impact variety.

  For the purpose of history, the fact that the Y does not recombine is the most perfect happenstance. What it means is that if there are differences between the Y of a father and that of his son, it’s not because someone else’s DNA got mixed in there too, but rather because something went wrong with the copying process. If we can identify the copying errors and compare them over many different Y chromosomes, we can build a tree of Y chromosomes and see the branching of all men, fathers and sons, starting in the present and going deep into the past, long before we started writing birth certificates or noting children’s name in Bibles, long before we even invented writing.

  There are two kinds of Y mix-ups that are especially interesting for this sort of research. Sometimes one of the letters of DNA is simply miscopied. This kind of mistake is extremely rare, and scientists who trace such variations are effectively tracking change through thousands and thousands of years. Another copying mistake occurs when a cluster of letters are accidentally repeated. A sequence G-A-T-A might be miscopied as G-A-T-A-G-A-T-A . In most cases, these short tandem repeats, as they are known, don’t appear to affect the function of the chromosome, but when you compare the short tandem repeats of related people, they can be used as markers for estimating when a common ancestor lived. (See chapter 14 for an example of a repeat that has a serious consequence.)

  If the bearer of a short tandem repeat on his Y chromosome has a son, that child will have the same copies on his Y. At some point further down the generational road, the bearer of the repeat may pass on another miscopied sequence to his son. You can follow the trail of repeats back through time to the original bearer, and they are especially handy for tracking people in the last eight hundred or so years.

  There’s something fairy tale–like about the way a male lineage has a biological marker. The seventh son of a seventh son is a lucky figure in myth, and for much of Western history the male line had real power in families, where a male heir is always preferred. Curiously enough, mothers have their own special genetic markers too, but they aren’t part of the human genome. Rather, they are found in mitochondria, which float in the space between the bubble of a cell nucleus and its outer layer. Mitochondria, typically called the cell’s powerhouse, are handy little machines, remnants of a single-celled organism that became permanently entwined in ancient cells long ago and gave rise to most life as we know it—all fungus, plants, and animals. Mitochondria have their own DNA, which is passed down from mothers to their children in the ovum. This means that everyone has the same mtDNA as his or her mother, but only daughters will pass it on. The identity of your mother and her mother and hers before her will always be stamped inside your cells.

  When you consider the puzzle of the genome overall, the Y chromosome and mtDNA are almost shockingly informative pieces of DNA. Think of your expanding tree of ancestors, parents to grandparents to great-grandparents, ever doubling as you go back yet one more generation. By the time you’ve reached ten generations back, there are 2,046 people in your family tree, each of whom (despite believing that the past stops with him or her) has nevertheless contributed to your existence and to your family’s genome.

  The sheer size of the pool is one reason people often throw up their hands and declare that all those generations of pairings quickly render any single contribution untraceable. But the Y chromosome and mtDNA track back through history in a single line, following fathers’ fathers and children’s mothers through time immemorial. What else do they tell us?

  • • •

  By the clear waters of the East Branch Pemigewasset River, surrounded by trees of gold, red, and green, there is a cluster of tents with flags of many stripes and colors fluttering in the breeze. It’s the Highland Games in New Hampshire, and each tent proudly displays the name of a clan—the MacGregors, the MacDougalls, and the Stewarts. On the tournament field shepherds compete, whistling to bright-eyed border collies that expertly harangue sheep around an obstacle course. A commentator entertains the crowd with tales about the dogs’ pedigree. Some of the sires are famous.

  Over a whiskey and a big cigar in the autumnal sunshine, I spoke to Donald MacLaren, aka Donald M’Donald V’Duncan V’Lauren, Chief Donald MacLaren of MacLaren and Achleskine, and sporting three golden eagle feathers in his beret to prove it. MacLaren was loquacious and charming, and if you met him and didn’t guess straight away that he was a British diplomat before retirement, you would not be surprised to find out. Whenever he is in the clan tent, he is subject to a mild mobbing. MacLarens from all over are excited to speak to him, and there is much joshing about the variety and volume of wine that was consumed the night before and how it might compare to the consumption in the coming evening.

  Here in the New World, those of us without documented history, or at least those of us who haven’t read the documents that track our history, enjoy something like a definitive sense of closure on the capital-P past. The past of kilts, swords, betrayal, and crowns was then; this is now. In some general sense we are aware that our ancestors lived in the early, middle, and late medieval periods—they must have—but here in the New World the door to all that has shut. Is this clarity or presentism?

  The MacLarens were a Picto-Scottish community long before the adoption of a common clan surname. While they took their name from a chief called Labhran who lived in the early 1200s, they trace their ancestry back to King Erc, a fifth-century ruler of Scottish Dalriada, the ancient kingdom that emerged on Stephen Leslie’s genetic map. Donald is descended from one of Erc’s two sons, King Lorn Mor. The current queen of England is descended from Erc’s other son, King Fergus Mor, which means that she and Donald are cousins, although more than fifty generations apart. It is not a relationship he has called on, he said.

  Although Donald has no official duties and could ignore the clan, as indeed some Scottish chiefs do, he took it on himself as a young man to go on a tour of North America and visit the far-flung MacLarens. Since retirement he’s led MacLaren celebrations many times, and there is much more fun in clan pageantry today than there used to be. For centuries the ancient tribes of Scotland tussled with one another and their overlords for power. Disagreements were often settled with a sword, and terrible betrayals and loss of life were common. A brief trip through the clan history with Donald is like stepping into the George R. R. Martin world of Game of Thrones.

  From the early twelfth century, the Scottish Crown began to impose feudalism on the clans. Yet despite its attempts to assert authority, there were long periods of lawlessness. “It was a hellish time,” explained Donald. “There was complete mayhem in the Highlands. They had ‘letters of fire and sword.’ If you applied to the Crown for a letter and you received it, it gave you patent to burn your enemies out of their home. There was total economic disintegration; there was homelessness; there were abandonments; there were bandits and reivers and cutthroats.”

  When the Scottish crown demanded that clans formally produce or apply for legal title to their own lands, Clan Labhran, that is, the MacLarens, refused, and they were reduced to the status of Crown tenants. A 1672 Act of Parliament decreed that clans must formally register their heraldic Arms, b
ut again the MacLarens would not comply, leaving them officially chiefless and landless. Over the centuries, as they engaged in local and national battles, the clan suffered significant losses. The sixteenth century took an especially harsh toll. As the MacLarens attempted to recover from a disastrous battle in which they fought for James IV, a rival clan, the MacGregors, attacked them twice without warning. In 1542, they arrived out of the dark forests at night, murdering twenty-seven men, women, and children. The second attack, sixteen years later, left eighteen complete households burned and murdered. The MacGregors then took over MacLaren land.

  It was around this time that the worldwide diaspora of the clans commenced, slowly at first. For some time, Scots had begun to disperse throughout Scotland but now they left for the continent. Two MacLaren families did very well for themselves there: Their founders joined the Swedish army and their Arms were recorded in the Swedish Register of Nobles. In the eighteenth and nineteenth centuries, Scots began to depart for North America, Australia, and New Zealand, many of them fleeing unhappy lives.

  It wasn’t until 1957 that the ancient chiefly Arms were finally officially recorded. Donald’s father assembled a significant amount of evidence to prove that he was in fact descended from the last known MacLaren chief, and he presented it to the Court of the Lord Lyon in Edinburgh, the Scottish heraldic authority that rules on title and is famously rigorous in its judgment. The court decreed that Donald’s father had indeed descended from the last-known chief of Clan MacLaren. When he was made chief, he acquired the legal title to some of the clan lands at Balquhidder that had been lost a few centuries earlier, including the famous Creag an Tuirc, the Clan’s rallying point from earliest times. When he died in 1966, his three golden feathers were passed on to his eleven-year-old son, now the twenty-fifth chief since Labhran.