Skip to comments.New Twist On Out-Of-Africa Theory
Posted on 07/14/2004 8:53:47 AM PDT by blam
New twist on out-of-Africa theory
ABC Science Online
Wednesday, 14 July 2004
Homo erectus, the species thought to be the first to leave Africa for Eurasia in the out-of-Africa model of human origin (Image: Science)
Early humans made love, not war, according to new DNA analysis presented at a genetics conference that gives a new twist on the out-of-Africa hypothesis of human origins.
U.S. researcher Professor Alan Templeton of Washington University, St Louis, debunks the prevailing version of the out-of-Africa hypothesis, which says early humans migrated from Africa and wiped out Eurasian populations.
Instead, they bred, he told the Genetics Society of Australia's annual conference in Melbourne this week.
Templeton said his evidence didn't support the so-called replacement theory in which African hominids caused the extinction of other Homo species.
Instead, he said his analysis of the human genome showed prehistoric gene-swapping created a single evolutionary lineage beginning in Africa and ending where we are today.
He looked at mitochondrial DNA, as well as DNA on a range of chromosomes including X and Y.
"The genetic legacy of current humans is predominantly of African origin," he said.
Templeton is the first to suggest expansion out of Africa occurred in three waves: 2 million years ago, 800,000 years ago and 100,000 years ago.
The alternative view suggests that expansion out of Africa occurred twice and caused the genetic extinction of existing populations, with the colonisers later diversifying into separate races.
What about races?
But Templeton said this extinction never happened and a combination of movement and interbreeding meant diversification of races didn't occur.
"We really have to abandon the idea of race. It actually does not reflect the genetic differences we can now measure in an objective fashion."
Templeton said the differences between human populations today were based on geography not genetics.
This meant a Norwegian would be more closely related than a Fijian to someone from sub-Saharan Africa.
"We do see differences in different regions of the world but the best indicator of those differences is simply geographical distance and not things like skin colour."
Templeton said his data was inconclusive on whether interbreeding also occurred with Neanderthals.
But he said there was fossil evidence that this probably occurred, which would imply a bit of Neanderthal could live on in us all.
Australian geneticist Associate Professor Philip Batterham from the University of Melbourne said the research showed humanity was far more closely related that previously thought and that race was a cultural phenomenon.
Templeton's research was published in the journal Nature in March 2002.
Look around you in America today at the various shades of skin color, from transluscent white to pitch-black and everything in between. Skin color gets more easily mixed than eye color.
Race, AFAIK, is not used scientifically, at least not by biologists.
This is simply not true. Many genetic diseases target specific races. Sickle Cell Anemia and Tay-Sachs to name two (Blacks and Jews, respectively).
The horses don't care, though. The only reason we care about what race people are is because there are political reasons involved.
Two blacks marry, their child will be black. Two green-eyed people married, and you have no idea what color the children's eyes will be.
A white and a black marry, and the child will be black.
Classification of people into race based on morphological characteristics is right and proper science. Treating humans differently because of those classifications is racism. Don't confuse the two.
The only reason we care about what race people are is because there are political reasons involved.
See my posts on genetic diseases.
I see your point, but I can't resist giving a biology lesson here. (This stuff fascinates me.)
There are several different genes controlling eye color; some are dominant and some are recessive. You get one gene from your mother and one gene from your father. Call the brown-eye gene B and the blue-eye gene b. Suppose both your parents have the combination Bb, i.e., a brown-eye gene and a blue-eye gene. Now brown-eye is dominant and blue-eye is recessive. So if your genetype is Bb, you have brown eyes. So look at the child of these parents. There are four equally-likely outcomes: BB, Bb, bB and bb. The first three outcomes result in brown eyes; but the last outcome gives you blue eyes. So two brown-eyed parents can have a blue-eyed child. Now, to my point: Suppose both parents have the genotype bb. Then the child is guaranteed to have genotype bb. So two blue-eyed parents will "breed true" in producing only blue-eyed children. (Of course, the truth of the matter is more complicated, since there are other eye colors running around that might be recessive to blue.)
The really curious story about genetics and color concerns calico cats. It turns out they don't breed true. To obtain a calico cat, you must combine the "tabby" gene with the gene for black hair. But both of these genes occur on the X chromosome, so to get both, the cat must be female. (Females have two X chromosomes but males are XY.) So all calico cats are female. But not really -- one in every 3500 calicos is male. Turns out that such cats have genotype XXY, they have an extra X.
I told you that guy is Lakota Sioux or a Jewish Guy with a wig.
I think it's a Velociraptor. Very intelligent. Hunt in packs.
On the one hand, you have the indisputable fact that non-mutant aberrant traits have to run in families to be passed on at all, and those families have extended families, etc.
On the other hand, you have the pseudo-concept of Race, entailing a host of innate 'differences', as proposed by determinists and positivists of various stripes over the last 150 years or so.
I guess I'm just not as good at connecting the dots as some. To me, the two ideas are as mutually exclusive as say, phlogiston and oxygen.
You and mine both. There was never any reason to make OOA and multi-regional mutually exclusive.
Leon Schuster I believe... a very very popular South African comedian.
Are you serious Clark?
Maybe in apartheid South Africa or the Old South. Their skin color will probably be somewhere between white and black. Why is such a child automatically considered black, in your mind?
If I recall correctly, Cyb is of mixed-race ancestry. I'd be curious to hear her take on this.
A white and black marry and the child will be MIXED race. So you are wrong. Next question? Like I said, you just demonstrated that race is politicial.
My father is white and my mother is West Indian Creole of mixed race origin herself. Here in America, there was the one drop rule that any black blood made you black for the purposes of slavery and segregation (heartily now championed by liberals!). South Africa a mixed race person is mixed race or coloured as more commonly know and the apartheid rules had its own peculiar set of limitations,etc.
Race is BS and made up by people with a deliberate agenda of their own.
Other stories of the period had Adam and Lilith both created from dust, and being equal Lilith refused to lie beneath Adam. When Adam tried to compel her by force, Lilith called on the sacred name of God, rose into the air and left him.
She wandered (transported? ) to the Red Sea, where she had a hundred babies each day, fathered by the demons that populated the area. As punishment, God would kill any male on the eight day that didn't have his mark (circumcision?). And since Lilith parted from Adam before the fall, she escaped the curse of death.
I'm not sure that it is helpful to characterize race as just "political". The many genetically determined characteristics which constitute "race" are real and have required many centuries to come about. That there are consequences to this effect should not be a surprise and calling them all "political" perhaps understates the challenge.
One poster pointed out the association of particular diseases with a single race. It may require politics to address the issue, but the issue is not of political origin. I would not term as political the forces in the past which led to the isolation and differentiation that we observe.
You are certainly correct that the offspring of people of different races are of mixed-race and not of a presumed inferior race. You responded probably with less derision than I might have.