Skeletal remains suggest modern man evolved in Africa about 200,000 years ago and began moving out of Africa about 60,000 years ago.
I participated in the National Geographic project to help plot the migration by sending in samples of my DNA. The "Y" chromosome is passed directly from father to son from generation to generation. From time to time, the "Y" chromosome can mutate naturally (which is usually harmless) producing a marker that then is passed down to sons and their sons, etc.
In most cases there are more than one mutation event which means that any of these markers can be used to determine your particular branch of the tree. They are called haplogroups, since every individual who has one of these markers also has the others.
When geneticist identify a marker, they try to figure out when it first occurred, and in which geographic region of the world. By tracking the lineages, a picture of how small tribes of modern humans in Africa diversified and spread to populate the world.
i belong to the R1b haplogroup. Today about 70% of men in southern England belong to the R1b haplogroup and over 90% in parts of Spain and Ireland.
There were approximately 10,000 humans when the ice age temporarily retreated. The African Ice Age was characterized by drought rather than cold and when the ice began to melt a period of warmer temperatures and a moister climate turned part of the Sahara into a savanna. Also about this time there was a significant leap forward in modern humans' intellectual capacity. Language emerged, weapons and tools improved, and group planning and cooperation gained.
M-89: Moving Through the Middle East
The next marker, found in 90-95% of all non-Africans, comes from a man from the Middle East, 45,000 years ago. About 40,000 years ago the climate shifted again and became colder and more arid. Drought returned to Africa and for the next 20,000 years, the Saharan Gateway was effectively closed giving my ancestors two options: remain in the Middle East or move on. Retreat back to Africa was not an option.
Some migrated from Iran to the steppes of Central Asia. These semiarid grass-covered plains formed an ancient "superhighway" stretching form eastern France to Korea.
M-9: The Eurasian Clan Spread Wide and Far
My next ancestor, born about 40,000 years ago was part of the Eurasian Clan which dispersed gradually over thousands of years. Seasoned hunters followed the hears eastward along the Eurasian steppe. Eventually their path was blocked by the mountain ranges of south Central Asia located in present day Tajikistan. Here the tribes split into two groups. Some moved north into Central Asia and others moved south into what is now Pakistan and Indian subcontinent. Most people native to the Northern Hemisphere trace their roots to the Eurasian Clan. Nearly all North Americans and East Asians are descent ants.
M-45: The Journey Through Central Asia
My next marker comes from a man from the Eurasian Clan, 35,000 years ago, that moved north onto the game rich steppes of present day Kazakhstan, Uzbekistan and southern Siberia.
Eventually, the glaciers began to expand again forcing my ancestors to follow the herds of game north. In order to exist, they learned to build portable animal-skin shelters and create weaponry and hunting techniques that would prove successful against the larger animals they encountered.
M-207: Leaving Central Asia.
Next, 30,000 years ago, a group head west towards the European subcontinent. Then they split into two groups, one continuing to Europe, the other making it as far as India.
M173:The First Modern Europeans
Humans continue to evolve used bone, ivory, antler, and shell as part of their tool kit. Jewelry was produced. My ancestors were able to better compete for scare resources against the Neanderthals, About 20,000 years ago the climate changes again with expanding ice sheets forcing a move to the south, including Spain, Italy, and the Balkans. And about 12,000 years ago they moved back north as the ice receded.
M-343: Direct Descendants of Cro-Magnon
I am a direct descendant of the people who dominated the human expansion into Europe, the Cro-Magnon. The cave paintings of the Cro-Magnon are far more intricate, detailed, and colorful than anything prior.
If my ancestors came from Africa, why do I have white skin? With less sun, skin became whiter so more melatonin could be absorbed in order to stay healthy. Evolution at work.
Sadly, the genetic traces of my ancestors' group ends between 5,000 and 10,000 years ago, though more details may be known as a result of extra information participants are invited to contribute about themselves. So there is still a gap between knowledge gained from genealogy and that from genetic searches. But that doesn't detract from the vital contribution the inter net has made to resolving the most fascinating of problems - who we really are.
If you are interested, go to www.genographic.nationalgeographic.com.
For a little over $100 you can learn your ancient history and add to the knowledge base of the continuing human migration.