Show Date: July 5, 2006 
Pam Eastlick for THE DEEP on line

COMMON ROOTS?

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond. Join us each week on Newstalk K57 on Wednesday night from 7 to 8 p.m. for exciting live science expeditions or listen live on our web site www.thedeepradioshow.com

You probably saw the recent news story by Matt Crenson that says that we are all genetically related. Now this should NOT come as news to you. The article cites the main reason for thinking this as simple statistics. “Every person has two parents, four grandparents and eight great-grandparents. Keep doubling back through the generations - 16, 32, 64, 128 - and within a few hundred years you have thousands of ancestors.” And as the article says, “Imagine there was a man living 1,200 years ago whose daughter was your mother's 36th great-grandmother, and whose son was your father's 36th great-grandfather. That would put him on two branches on your family tree, one on your mother's side and one on your father's. In fact, most of the people who lived 1,200 years ago appear not twice, but thousands of times on our family trees, because there were only 200 million people on Earth back then.

Simple division - a trillion divided by 200 million - shows that on average each person back then would appear 5,000 times on the family tree of every single individual living today.”

Of course, many people die childless, but these statistical facts are undisputable. There is no question that every single human on the face of the planet is related to every other human. Where I beg to disagree with the news article is when they state “Allowing very little migration, Rohde's [One of the researchers for the data used] simulation produced a date of about 5,000 B.C. for humanity's most recent common ancestor. Assuming a higher, but still realistic, migration rate produced a shockingly recent date of around 1 A.D. ”So, they’re saying that someone at the time of the Roman Empire is the ancestor of us all.

I fear they are wrong because they completely ignore a very large human population. They neglect to include in their calculations the entire population of the Americas and the entire population of the Pacific Ocean (not to mention the Australian aboriginals).

Before the 1500’s, none of these peoples had had any genetic contact with the rest of the world for at least 10,000 years. The article states “In the New World, the Navaho moved from western Canada to their current home in the American Southwest. People from East Asia fanned out into the South Pacific Islands, and Eskimos frequently traveled back and forth across the Bering Sea from Siberia to Alaska.” But Africans, Europeans and Asians cannot share a common ancestor with Incas, Seminoles, Australian aboriginals or Chamorus that lived as recently as 2,000 years ago because all the mentioned migrations happened a lot longer ago than 2,000 years. There were no Eskimo traders in the 800’s who came from Siberia and traveled to Patagonia (in South America). The isolated tribes of the Amazon who were contacted by other peoples in the last century certainly share no common ancestors that lived as recently as 2,000 years ago with most of humanity.

There is NO question that we all share common ancestors; but they may not have lived as recently as this article would lead you to believe. Join us the week on The Deep as we delve into our common past.

The Deep is broadcast on Newstalk K57 every Wednesday night at 7:00 p.m. You can also listen live from our web site www.thedeepradioshow.com. Join Jim Sullivan, Pam Eastlick, and Peter Melyan on the deepest radio show on Earth.