Mike's Genealogy Site
Y Chromosome DNA Analysis
The National Geographic Society, IBM, and geneticist Spencer Wells, are sponsoring a project to trace an individual's deep ancestry through DNA analysis of easily obtained cheek swab specimens. I ran this analysis on my own DNA, and archived the results from the National Geographic Y chromosome DNA analysis page here. I have slightly modified the text and the map to improve readibility, and added some of my own explanatory text.
Most people are familiar with the concept of DNA, the long molecules present in the center (the nucleus) of each and every one of our cells that contain the "instructions" for making a particular type of cell. Whether the cell is part of the liver, the brain, the muscle or a "stem cell" (with the potential to develop in a number of ways), it has the same set of instructions, only using those which are necessary for the task at hand. Every cell of an individual human - or plant or animal, for that matter - contains exactly the same DNA (with the exception of tumor cells, representing potentially lethal changes in the instruction sequence). The instructions are coded by specific arrangements of four types of subunits in the DNA molecule known as nucleides, which pair up on adjacent strands of DNA: adenine (A) pairing with guanine (G), and cytosine (C) pairing with thymine (T).
This project traces the DNA on the Y chromosome, which traces paternal heritage. Unlike the mitochondrial DNA analysis which traces the maternal line, only males have a Y chromosome, and it is passed from father to son. Small changes in DNA from time to time are identifiable as specific mutations. These are usually not harmful, but are passed on to all subsequent generations. By tracking the presence of various mutations on the Y chromosome, it is possible to determine where various groups of humans lived and migrated over many thousands of years.
The map traces the migratory path taken by my paternal ancestors up to the point of divergence of the most recent subdivision, M172 marker in Haplogroup J, about 10,000 years ago. The descendants of the first male with this specific mutation (including me) seem to have left the fertile crescent and spread around the borders of the Mediterranean Sea.
My own Y-DNA analysis from the National Geographic project
Haplogroup J2 (M172)
Short Tandem Repeats:
DYS393: 12
DYS439: 11
DYS388: 16
DYS385a: 14
DYS19: 14
DYS389-1: 13
DYS390: 23
DYS385b: 15
DYS391: 10
DYS389-2: 17
DYS426: 11
DYS392: 11
How to Interpret Your Results
Above are results from the laboratory analysis of your Y-chromosome. Your DNA was analyzed for Short Tandem Repeats (STRs), which are repeating segments of your genome that have a high mutation rate. The location on the Y chromosome of each of these markers is depicted in the image, with the number of repeats for each of your STRs presented to the right of the marker. For example, DYS19 is a repeat of TAGA, so if your DNA repeated that sequence 12 times at that location, it would appear: DYS19 12. Studying the combination of these STR lengths in your Y Chromosome allows researchers to place you in a haplogroup, which reveals the complex migratory journeys of your ancestors. Y-SNP: In the event that the analysis of your STRs was inconclusive, your Y chromosome was also tested for the presence of an informative Single Nucleotide Polymorphism (SNP). These are mutational changes in a single nucleotide base, and allow researchers to definitively place you in a genetic haplogroup.
*NB: If your results indicate "null," this is a situation in which the lab was unable to obtain a result for this marker (aka location) in your DNA. Possible causes include a deletion in your DNA sequence that removed the entire marker, or a mutation near the marker that causes the test to be unable to "find" the marker in order to test it. While uncommon, this does occur occasionally.
Your Y-chromosome results identify you as a member of haplogroup J2.
The genetic markers that define your ancestral history reach back roughly 60,000 years to the first common marker of all non-African men, M168, and follow your lineage to present day, ending with M172, the defining marker of haplogroup J2. Some in this lineage also carry the markers M47 (J2a), M12 (J2e), M67 (J2f), and M92 (J2f1).
If you look at the map highlighting your ancestors' route, you will see that members of haplogroup J2 carry the following Y-chromosome markers:
M168 > M89 > M304 > M172
Today, descendants of this line appear in the highest frequencies in the Middle East, North Africa, and Ethiopia, and at a much lower frequency in Europe, where it is observed exclusively in the Mediterranean area. Approximately 20 percent of the males in southern Italy carry the marker, along with ten percent of men in southern Spain.
What's a haplogroup, and why do geneticists concentrate on the Y-chromosome in their search for markers? For that matter, what's a marker?
Each of us carries DNA that is a combination of genes passed from both our mother and father, giving us traits that range from eye color and height to athleticism and disease susceptibility. One exception is the Y-chromosome, which is passed directly from father to son, unchanged, from generation to generation.
Unchanged, that is unless a mutation?a random, naturally occurring, usually harmless change?occurs. The mutation, known as a marker, acts as a beacon; it can be mapped through generations because it will be passed down from the man in whom it occurred to his sons, their sons, and every male in his family for thousands of years.
In some instances there may be more than one mutational event that defines a particular branch on the tree. What this means is that any of these markers can be used to determine your particular haplogroup, since every individual who has one of these markers also has the others.
When geneticists identify such a marker, they try to figure out when it first occurred, and in which geographic region of the world. Each marker is essentially the beginning of a new lineage on the family tree of the human race. Tracking the lineages provides a picture of how small tribes of modern humans in Africa tens of thousands of years ago diversified and spread to populate the world.
A haplogroup is defined by a series of markers that are shared by other men who carry the same random mutations. The markers trace the path your ancestors took as they moved out of Africa. It's difficult to know how many men worldwide belong to any particular haplogroup, or even how many haplogroups there are, because scientists simply don't have enough data yet.
One of the goals of the five-year Genographic Project is to build a large enough database of anthropological genetic data to answer some of these questions. To achieve this, project team members are traveling to all corners of the world to collect more than 100,000 DNA samples from indigenous populations. In addition, we encourage you to contribute your anonymous results to the project database, helping our geneticists reveal more of the answers to our ancient past.
Your Ancestral Journey: What We Know Now
M168: Your Earliest Ancestor
Fast Facts
Time of Emergence: Roughly 50,000 years ago
Place of Origin: Africa
Climate: Temporary retreat of Ice Age; Africa moves from drought to warmer temperatures and moister conditions
Estimated Number of Homo sapiens: Approximately 10,000
Tools and Skills: Stone tools; earliest evidence of art and advanced conceptual skills
Skeletal and archaeological evidence suggest that anatomically modern humans evolved in Africa around 200,000 years ago, and began moving out of Africa to colonize the rest of the world around 60,000 years ago.
The man who gave rise to the first genetic marker in your lineage probably lived in northeast Africa in the region of the Rift Valley, perhaps in present-day Ethiopia, Kenya, or Tanzania, some 31,000 to 79,000 years ago. Scientists put the most likely date for when he lived at around 50,000 years ago. His descendants became the only lineage to survive outside of Africa, making him the common ancestor of every non-African man living today.
But why would man have first ventured out of the familiar African hunting grounds and into unexplored lands? It is likely that a fluctuation in climate may have provided the impetus for your ancestors' exodus out of Africa.
The African ice age was characterized by drought rather than by cold. It was around 50,000 years ago that the ice sheets of northern Europe began to melt, introducing a period of warmer temperatures and moister climate in Africa. Parts of the inhospitable Sahara briefly became habitable. As the drought-ridden desert changed to a savanna, the animals hunted by your ancestors expanded their range and began moving through the newly emerging green corridor of grasslands. Your nomadic ancestors followed the good weather and the animals they hunted, although the exact route they followed remains to be determined.
In addition to a favorable change in climate, around this same time there was a great leap forward in modern humans' intellectual capacity. Many scientists believe that the emergence of language gave us a huge advantage over other early human species. Improved tools and weapons, the ability to plan ahead and cooperate with one another, and an increased capacity to exploit resources in ways we hadn't been able to earlier, all allowed modern humans to rapidly migrate to new territories, exploit new resources, and replace other hominids.
M89: Moving Through the Middle East
Fast Facts
Time of Emergence: 45,000 years ago
Place: Northern Africa or the Middle East
Climate: Middle East: Semi-arid grass plains
Estimated Number of Homo sapiens: Tens of thousands
Tools and Skills: Stone, ivory, wood tools
The next male ancestor in your ancestral lineage is the man who gave rise to M89, a marker found in 90 to 95 percent of all non-Africans. This man was born around 45,000 years ago in northern Africa or the Middle East.
The first people to leave Africa likely followed a coastal route that eventually ended in Australia. Your ancestors followed the expanding grasslands and plentiful game to the Middle East and beyond, and were part of the second great wave of migration out of Africa.
Beginning about 40,000 years ago, the climate shifted once again and became colder and more arid. Drought hit Africa and the grasslands reverted to desert, and for the next 20,000 years, the Saharan Gateway was effectively closed. With the desert impassable, your ancestors had two options: remain in the Middle East, or move on. Retreat back to the home continent was not an option.
While many of the descendants of M89 remained in the Middle East, others continued to follow the great herds of buffalo, antelope, woolly mammoths, and other game through what is now modern-day Iran to the vast steppes of Central Asia.
These semi-arid grass-covered plains formed an ancient "superhighway" stretching from eastern France to Korea. Your ancestors, having migrated north out of Africa into the Middle East, then traveled both east and west along this Central Asian superhighway. A smaller group continued moving north from the Middle East to Anatolia and the Balkans, trading familiar grasslands for forests and high country.
M304: The Spread of Agriculture
Fast Facts
Time of Emergence:15,000 to 10,000 years ago
Place of origin: Fertile Crescent
Climate: Ice Age ending
Estimated Number of Homo sapiens: Millions
Language: Unknown?earliest evidence of modern language families
Tools and Skills: Neolithic Revolution
The patriarch of haplogroup J2 was a descendant of the M89 Middle Eastern Clan. He was born between 15,000 to 10,000 years ago in the Fertile Crescent, a region that extends from the Mediterranean Sea to the Persian Gulf where the Euphrates and Tigris rivers form an extremely rich floodplain. Today the region includes all or part of Israel, the West Bank, Jordan, Lebanon, Syria, and Iraq.
The descendants of this man played a crucial role in modern human development. They pioneered the first Neolithic Revolution, the point at which humans changed from nomadic hunter-gatherers to settled agriculturists. The end of the last ice age around 10,000 years ago, and the subsequent shift in climate to one more conducive to plant production, probably helped spur the discovery of how to grow food.
Control over their food supply marks a major turning point for the human species: the beginning of civilization. Occupying a single territory required more complex social organization, moving from the kinship ties of a small tribe to the more elaborate relations of a larger community. It spurred trade, writing, and calendars, and pioneered the rise of modern sedentary communities and cities.
The M304 marker appears at its highest frequencies in the Middle East, North Africa, and Ethiopia. In Europe, it is seen only in the Mediterranean region.
An important subgroup of haplogroup J includes the descendants of another man from the M89 Middle Eastern Clan born in the Fertile Crescent at about the same time, carrying the marker M172. This related haplogroup is called J2.
The early farming successes of these lineages spawned population booms and encouraged migration throughout much of the Mediterranean world.
M172: Toward the Mediterranean
Fast Facts
Time of Emergence: 10,000 years ago
Place of Origin: Fertile Crescent
Climate: Ice Age ending
Estimated Number of Homo sapiens: A few million
Language: Unknown
Tools and Skills: Neolithic
Your ancestors left a physical footprint that matches their genetic journey. Artifacts from ancient towns such as Jericho, also known as Tell el-Sultan, a site close to present day Jerusalem, provide evidence of permanent human settlements to around 8500 B.C. The sites also suggest the transition from hunter-gatherer to settled life occurred relatively suddenly.
The M172 marker defines a major subset of haplogroup J, which arose from the M89 lineage. It is found today in North Africa, the Middle East, and southern Europe. In southern Italy it occurs at frequencies of 20 percent, and in southern Spain, 10 percent of the population carries this marker. Both haplogroup J and its subgroup J2 are found at a combined frequency of around 30 percent amongst Jewish individuals.
This is where your genetic trail, as we know it today ends. However, be sure to revisit the National Geographic Geneographic project site from time to time. As additional data are collected and analyzed, more will be learned about your place in the history of the men and women who first populated the Earth. We will be updating these stories throughout the life of the project.