Tuesday 14 May 2013

African roots of the human family tree

African roots of the human family tree

Professor Ron Clarke and his team at Wits University, South Africa, excavated "Little Foot" -- an "australopithecus" or kind of an ape-man that changed our understanding of pre-human evolution. Professor Ron Clarke and his team at Wits University, South Africa, excavated "Little Foot" -- an "australopithecus" or kind of an ape-man that changed our understanding of pre-human evolution.
Johannesburg, South Africa (CNN) -- How would you feel knowing you are related to your boss, your neighbor, or better yet your partner? Don't worry, you may have to go back 1,000, 20,000 or maybe even 100,000 years to find a common ancestor, but generally speaking it is true.
Advanced DNA testing combined with recently unearthed discoveries are bolstering the belief that if you look back far enough, all living human beings are the descendents of a small, innovative and ambitious set of people on the African continent.
With the mapping of the human genome in 2003, combined with thousands of people around the world submitting their DNA for testing, there's now mounting physical proof we all started in Africa before migrating around the world.
Geneticists are able to identify certain genetic sequences or "markers" in each of us and cross-reference it with a number of ever-growing international databases. Where there's a match, there's likely a common ancestor and genetically speaking, all markers point to Africa.
 
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People take comfort in having their DNA tested, says Dr. Himla Soodyall. "It gives them some sense of grounding, some homing and some essence of understanding who they are," she says. Soodyall is the founder and director of the Human Genetics laboratory in South Africa's National Health Laboratory Services. She says she dedicated her life to this field of study because it reveals a much more fascinating story than most people realize.
I recently sat down with Soodyall to have my own DNA tested and its accuracy was astounding.
She explained all of us carry our mother's DNA signature within our mitochondria, so it houses "markers" only from our mother's lineage. My maternal marker turned out to be "H" which can be traced to a woman living in the Dordogne region of France 20,000 years ago.
But this isn't reserved for my British mother and me -- 47% of all Europeans are descendants from this haplogroup, which itself is an offshoot of humans who migrated out of Africa and into Europe.
Similarly, on my Jamaican father's side I expected an African connection due to the trans-Atlantic slave trade, in which the Caribbean was involved. Soodyall isolated DNA housed in my Y-chromosome, which only males carry. It revealed an "E3a" genetic marker common in 96% of people from Central West Africa.
What's more amazing was the discovery that certain sequences of my DNA matched up perfectly with a man from Zanzibar, Tanzania, and another from the Democratic Republic of Congo, who also had their DNA tested recently.
My family got a real kick out of hearing specifics related to our ancestry, but for me personally it underscored the reality that we really are one large, diverse and often dysfunctional human family. Ironically, what connects us all is the fact we really do want to understand more about our heritage; the only difference is how much people -- of any color -- are willing to admit their African roots.
What makes us human is that we analyze our surroundings. We want to know how things work.
Professor Ron Clarke, Wits University, South Africa
Down along the scenic coastline of South Africa, Professor Christopher Henshilwood is digging up the anthropological proof of our human African origins. In the Blombos Cave, over the years he and his team have painstakingly unearthed beads likely used by humans on necklaces 75,000 years ago, bone tools dating back 80,000 years and the world's earliest known painting kit.
Because these findings are the oldest of their kind, it suggests our modern human behavior began in Africa and has been developing ever since. For example, the ancient "painting kit" contained red ochre and was likely used as body paint, just as the Himba people of Namibia use it today. Henshilwood says this symbolic behavior is what set humans apart. "It's the makeup people wear today ... the shoes we wear, the language we speak," he explains. "These are all sending out messages to the people around us about who I am, and where I come from."
For the past century in Ethiopia, Kenya, Tanzania and South Africa, ancient fossils dating back millions of years continue to emerge suggesting a common ancestor for humans. "Lucy", "The Black Skull," "Twiggy" and "The Taung Child" respectively prove there were walking beings similar to humans in Africa before us Homo sapiens emerged.
Professor Ron Clarke of Wits University in South Africa recently took CNN deep inside the Sterkfontein Cave at the Cradle of Humankind World Heritage Site to expose one more example.
It was here he and his team unearthed the most complete skeleton of Australopithecus ever found. In very non-scientific terms, it can be described as a type of ape-man with anatomical similarities to the modern ape and the modern human. It is at least 3 million years old and Clarke, who has yet to publish some of his findings, says he was shocked when he realized what it was.
Whether people believe humans evolved from another species or that we all migrated out of Africa or not, one aspect of our human condition is undeniable, says Clarke. In a sentiment echoed by Soodyall and Hesnshilwood, Clarke says: "What makes us human is that we analyze our surroundings. We want to know how things work. When, why, where? And so one of the big questions is how did we become human?"

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