The one key point worth mentioning that makes this all possible is the following. Basically the "Y" chromosome changes little from generation to generation. Males are XY, and females are XX. Before our eggs and sperm mix, there's a lot of mixing of DNA parts within the genes. But that mostly happens on the X chromosome. The Y pretty much stays intact. It also mutates on an infrequent basis, allowing us to follow markers as populations travel from the East African origin of man (homo sapiens) to the rest of the world about 60,000 years ago.
Another thing worth mentioning is the whole concept of retaining the name of the male from generation to generation. Is it relevant or just sexist? Since the Y chromosome stays constant - and the name follows this Y chromosome, then it turns out to be HIGHLY relevant. Go figure...
Fear not, women. We can trace you with mitochondrial DNA! Read on below.
Anyhow, this article was in the Wall Street Journal Online. Enjoy.
- Bill
Project Hopes to Trace
Your Ancestors Back 10,000 Years
By CHARLES FORELLE
Staff Reporter of THE WALL STREET JOURNAL
April 13, 2005; Page B1
About sixty thousand years ago, while large swaths of the globe were still shrouded in ice, a few groups of enterprising humans began to move north from the steppes and valleys of East Africa, most scientists believe. They eventually populated the rest of the world.
For $99.95, you may be able to see what path your ancestors took on their migration to their eventual home.
The trick lies in persistent markers left in DNA from generation to generation. Scientists at the National Geographic Society and International Business Machines Corp.'s Watson Research Labs are assembling a massive genetic database that will catalog these markers and associate them with genetic markers in other people, tracing them back to isolated, indigenous populations. The hope is that such correlations can show the routes early humans traveled, who they met along the way and how societies developed.
Anyone around the world with an Internet connection and a credit card can participate in the effort, called the Genographic Project. Starting today, National Geographic will mail out a kit containing two swabs and a pair of plastic vials for $99.95. Scrape some cells off the inner wall of your cheek, send them back and you'll be able to check a Web site a few weeks later to see, roughly, where you sit in the human family tree, the program's sponsors say. Participants can keep checking the Web site as the research improves.
At the database's core will be 100,000 samples that scientists will draw over the next five years from indigenous populations -- people with the clearest lines of descent and migration. The project will compare these DNA results with those of the people who submit samples to the program to search for patterns.
The aim is to create the largest and most detailed map of human lineage, one that "fills in the twigs of this family tree," says Spencer Wells, National Geographic's lead researcher on the project.
The effort comes as recent advances in genetic analysis have turned what used to be an expensive research endeavor into a basic lab test. Commercial companies have also jumped in: Family Tree DNA of Houston, which will analyze DNA for the National Geographic project, already sells a genetic tracing service that allows people to discover possible family relationships.
Mr. Wells says time is running out for a large-scale examination of human genetic history. The ease of travel is eroding indigenous groups, and modern cities become more genetically tangled by the day.
The $40 million project is the brainchild of Mr. Wells, a geneticist and explorer-in-residence at National Geographic who has long studied population movements. Mr. Wells says previous studies have looked at about 10,000 gene samples -- enough only to paint migration patterns in broad brush strokes.
More samples means more detail, and he hopes the project, which will run for five years, will get hundreds of thousands of samples, both from the paying public and from the indigenous groups.
The money raised from the sale of kits will be used to finance research on indigenous populations, and a portion will go to a fund that preserves their culture. IBM is contributing cash, computers, scientists and software to the nonprofit venture as a way to demonstrate its skills in life sciences, a growing market for the computer giant.
With enough data, Mr. Wells says, participants in the project may be able to trace their lineage all the way to the particular region their ancestors inhabited some 10,000 years ago, when many humans abandoned their wandering ways and settled into agrarian societies. He even hopes that the data will reflect more recent history -- perhaps even some day spotting markers that follow, for instance, Alexander the Great's army as it burst beyond Greece.
The task is made possible by a handy fact of genetics. Though a person's genetic code generally arises out of a shuffling of DNA from mother and father, most of the genetic material on the Y chromosome, which is present only in men, passes undisturbed directly from father to son. To trace the descent of women, scientists will examine DNA from inside a cell's mitochondria, its energy-producing engines. Mitochondrial DNA passes directly from mother to children. (A woman wanting to know about her father's family will have to turn to him or a brother for a DNA sample.)
Over time, these genes mutate, but only rarely, and the mutations serve as signposts along the migratory path. By sampling the DNA of people around the world and observing the mutations, scientists can reconstruct the broad patterns in the migration of early humans as the family tree, as most scientists believe, spread out of Africa into the Middle East, and then to Asia, Europe and beyond.
For instance, the genetic evidence indicates that about 50,000 years ago, men with a Y chromosome marker known as M168 moved northward from East Africa. About 5,000 years later, this branch produced the M89 mutation on the Arabian peninsula. By tracking subsequent mutations, researchers have been able to trace other groups of humans through central Asia and on to Europe. A genetic marker in this tree is still present in many men of European descent.
Assembling a large-scale genetic database is not without controversy. Privacy advocates worry whose hands the information could fall into. National Geographic insists that there's no way it could link a sample to a person, even if subpoenaed to do so. It also says it will sequence only a tiny portion of the genome -- just enough to pick out the migration marker -- and won't maintain any data that gives information about a person's health status.
Marc Rotenberg, executive director of the Electronic Privacy Information Center, a privacy group in Washington, D.C., says amassing a DNA database can have a legitimate and fruitful research purpose, but consumers should be wary of both hidden commercial interests -- such as insurers wanting to know about health information captured in DNA -- and of the potential that an organization loses control of the data. Organizations can have good intentions, Mr. Rotenberg says, but sometimes "other things intrude. It can be a subpoena, it can be a great business opportunity, it can be a security breach."
Scientists say the rewards of the project could be big. Humankind's precise migratory routes are educated guesses, filled in by clues from archaeology and anthropology. And there are plenty of questions to which the fossil record and existing genetics don't provide a concrete answer. Did early Europeans make an Atlantic crossing? Did Polynesians reach South America by boat? Did Neanderthal Man and homo sapiens, which lived in Europe at the same time about 30,000 years ago, interbreed?
Part of the reason genetics has a hard time giving answers, and why a giant sample may help, is that humans haven't been around long enough to show a lot of genetic change, says Scott Edwards, an evolutionary biologist at Harvard University who sits on the project's advisory board. "I don't think the Genographic Project will provide all the answers," he says. "but it'll be a very exciting stab at these age-old questions."
Ajay Royyuru, a biologist who is IBM's lead researcher on the project, says he can trace his family back about six generations, largely through word of mouth, but "beyond that it is total darkness to me." A larger database, he says, would brighten up the picture.
Write to Charles Forelle at charles.forelle@wsj.com
