African roots of the human family tree
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.
Tracing human origins
African beads rewrite the human story?
Reading your ancestry like a novel
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
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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