The Invisible History of the Human Race (24 page)

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?

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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, but 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.

 • • • 

If Santa wore a tartan kilt and were excellent at math, he might look a little like Bob McLaren, the clan’s genealogist. A senior scientist in an engineering and manufacturing company until he retired in 2004, McLaren founded the genetic surname project for the clan. At the Highland Games he greets visitors to the tent: an older couple, a rival clan member, a young woman with a tattoo circling her wrist (the words “my darling” in Scots Gaelic). With patient, tireless enthusiasm he tells them about the MacLaren DNA project. There are over 850 members in the project, he said, of whom 754 have had their Y DNA tested. In fact, Bob’s project is one of the largest and fastest-growing Y DNA projects in the world.

Y DNA project directors have a lot in common with the eighteenth-century natural historian Carl Linnaeus and his disciples, adventurers who launched expeditions in search of plants and animals, amassing big collections and then carefully creating taxonomies to describe and explain them. McLaren encourages people within the clan to get their DNA analyzed; then he works out how the owners of the Y chromosomes are related to one another by determining what their Y DNA has in common and what makes it different.

McLaren is an extremely skilled amateur. He and directors like him are not only spearheading private science projects but also changing the way the science is done. Over the years they have worked with Family Tree DNA, the first genetic genealogy company to market a Y DNA test, to shape the tests so they include as much useful information as possible.

The company’s first offering analyzed twelve segments of Y DNA, counting how many short tandem repeats occurred in each. A test that looked at an additional thirteen segments was developed next. Ultimately both tests gave a pretty low resolution of the past. While lots of people matched one another perfectly on twenty-five segments of the Y, it wasn’t clear precisely how. Brothers, fathers, sons, and distant cousins could all have the same result. Not only was the number of segments not useful, McLaren told me, but also there was nothing about the segments that was particularly helpful for tracing bloodlines.

In fact, the first twenty-five segments on the Y test were chosen only because scientists had already developed the tools to isolate them. Geneticists created synthetic primers—enzymes that attach to the flanks of the short tandem repeat—and each different segment required its own primer.

McLaren and his fellow project directors wanted better options, so, as McLaren put it, “
We beat on FT DNA to give us more.” The company increased the number of short tandem repeats on the test to thirty-seven and they chose more carefully what the additional twelve segments would be, targeting repeats that were known to change more quickly than others. Because they are more likely to change, two Y chromosomes that match in those places may share a more recent common ancestor.

Now, says McLaren, “If you match thirty-seven for thirty-seven with someone, then you’re really onto something.” People who match on this test certainly have a common ancestor, and they are likely more recent than those who match in fewer places. Yet still, as time passed and greater numbers of people took the test, more of them matched on the thirty-seven-segment test. A few years later a test that looked at sixty-seven places on the Y was developed.

Customers who matched perfectly on the first 37 segments learned that they probably had a common ancestor but not a particularly close one. If they matched on all 67 places, said McLaren, then their ancestor would be a lot closer to both of them. More recently the company has offered an 111 segment test.

Because of Bob McLaren’s project, we now know there are many different MacLaren Y chromosomes. This is to be expected, as people could become part of the clan through birth, marriage, or adoption. He showed me a spreadsheet of the clan’s Y chromosomes, some of which he believes to be of an ancient Scottish lineage. The point of creating this catalog of Y DNA, McLaren explained, is to help people with their genealogies, not to include or exclude people from the clan.

As for the chief, the documentation that links Donald to his seventeenth-century ancestor forms a compelling body of evidence, but it is just one line of evidence. However, Bob McLaren’s analysis seems to agree with the Lyon court’s ruling. According to Bob, the chief’s Y-DNA results, “place him in a cluster of MacLarens who appear related, but for many of them the relationship is quite a distance back in time,
an old Scottish lineage.” A fairly large number of people in Bob’s project fall into this cluster, and while they have similar values of short tandem repeats, there are enough differences to suggest their common ancestor is from long ago.

“There is no single short tandem repeat that points to the age of Donald’s association with the Clan,” Bob explained. “Rather, it is the collection of short tandem repeats that lead me to this conclusion. There is one short tandem repeat that is almost unique to this cluster but I need the others to validate this.”

I asked Donald about the Y-DNA testing. “It’s a wonderful way to complement whatever knowledge we have,” he said and then, laughing, added, “If I thought I was maybe a Sinclair or something like that, I might not do it, but I was very happy when the clan genealogist asked me to test.”

Is it only clans that share a cluster of Y chromosomes? What about any group of people who happen to have the same name?

 • • • 

Names are powerful symbolic markers. They tell us what has traditionally been most important: Names are unique identifiers, and they encode our ancestry as well. In our surname is our father’s name and his before him. Of course, they also have practical applications. In the early twentieth century, when the communist government of Mongolia outlawed surnames, it is alleged that more cases of accidental incest arose, presumably because people didn’t know if they were related or not. When the noncommunist government later reinstated last names, the prime minister at the time also claimed that family names reduced crime and increased social responsibility. (Ironically, it was feared at the time that an overwhelming majority of Mongolians who couldn’t recover what their actual family name had been might want to adopt Genghis Khan’s name.) Certainly it’s easier to run a country when you can identify people by last name and family affiliation.