Well, here we go again. Just when we thought we had our theories straight about our ancestors and how they left the savannas of Africa and some headed north west, while others went east. About how our ancestors, Homo Sapiens, were genetically distinct, we get told it ain't so!.
Oh yes, about a million years ago our archaic ancestors left Africa and moved into what is now Europe and Asia. But by some 30,000 years ago, all those archaic ancestors, the Neandertals and such, were gone...replaced by the modern version of our ancestors. The theory some twenty years ago was that Homo Sapien developed later, also in Africa and spread out from there in fits and spurts, colonizing in small enclaves and beating out the Neandertals. Killing them off or simply starving them out.
Um, no...that's not how it happened.
So what's the real story? Scoot past that mangled orange helix and find out.
The basic theory, called "serial founder effect model", declared that separate human enclaves developed differently because of geographic locations, accounting for the various looks of humans and other adaptations, such as the adaptation to thinner atmosphere in Tibetans and Andeans.
From the results of early DNA studies in the late 1980s and early ’90s, scientists argued that anatomically modern humans evolved in Africa, and then expanded into Asia, Oceania, and Europe, beginning about 60,000 years ago. The idea was that modern humans colonized the rest of the world in a succession of small founding groups—each one a tiny sampling of the total modern human gene pool. These small, isolated groups settled new territory and replaced the archaic humans that lived there. As a result, humans in different parts of the world today have their own distinctive DNA signature, consisting of the genetic quirks of their ancestors who first settled the area, as well as the genetic adaptations to the local environment that evolved later.
http://www.psmag.com/...
Twenty years ago, the human genome had not been sufficiently mapped, so other than some basic DNA studies, little was known about the genetic make-up of modern man. However, a wealth of studies done on human DNA in recent years has led to some startling insights.
Our modern ancestors didn't conquer the Neandertals...they married 'em.
Well to be more accurate, they had sex with them and had children with them.
We show that Neandertals shared more genetic variants with present-day humans in Eurasia than with present-day humans in sub-Saharan Africa, suggesting that gene flow from Neandertals into the ancestors of non-Africans occurred before the divergence of Eurasian groups from each other.
http://www.ncbi.nlm.nih.gov/...
So this mingling of body fluids, eggs and sperm must have happened shortly after humans began to migrate throughout the Eurasian continent, meeting other groups of our ancestors. Joining with them and living a fairly nomadic lifestyle. Eventually humans settled in geographic areas and by roughly 8,000 years ago, were introduced to farming by new settlers from the Levant and Anatolia in the near east.
New studies done by Joseph Pickrell at the New York Genome Center and David Reich at Harvard University have shown the diversity of the human genome. they show that all modern humans share both the DNA of both the hunter- gatherer and the farmers, so again, we conveniently mated, instead of warring. But some genetic material was not from either the hunter gatherers or the farmers.
So whose was it?
The answer came from sampling the DNA of nine ancient bodies; a 7,000 year old farmer from Germany, several 7 and 8,000 year old hunter gatherers from Luxembourg and Sweden, and the remains of a 24,000 year old boy buried at Mal'ta near Lake Bailkal in eastern Siberia
The findings suggest that the arrival of modern humans into Europe more than 40,000 years ago was followed by an influx of farmers some 8,000 years ago, with a third wave of migrants coming from north Eurasia perhaps 5,000 years ago. Others from the same population of north Eurasians took off towards the Americas and gave rise to Native Americans.
http://www.rawstory.com/...
Say what!?
You mean those European ancestors didn't just mate with Neandertals and farmers, but with the ancestors of Native Americans? What a randy bunch!
Here we sequence the draft genome of an approximately 24,000-year-old individual (MA-1), from Mal’ta in south-central Siberia9, to an average depth of 13. To our knowledge this is the oldest anatomically modern human genome reported to date. The MA-1 mitochondrial genome belongs to haplogroup U, which has also been found at high frequency among Upper Palaeolithic and Mesolithic European hunter-gatherers10–12, and the Y chromosome of MA-1 is basal to modern-day western Eurasians and near the root of most Native American lineages5. Similarly, we find autosomal evidence that MA-1 is basal to modern-day western Eurasians and genetically closely related to modern-day Native Americans, with no close affinity to east Asians.
http://www.ncbi.nlm.nih.gov/...
And yet another surprise!! Native Americans did not descend from east Asian roots, but from western Eurasians.
Here we report the genome sequence of a male infant (Anzick-1) recovered from the Anzick burial site in western Montana. The human bones date to 10,705 ± 35 (14)C years bp (approximately 12,707-12,556 calendar years bp) and were directly associated with Clovis tools. We sequenced the genome to an average depth of 14.4× and show that the gene flow from the Siberian Upper Palaeolithic Mal'ta population into Native American ancestors is also shared by the Anzick-1 individual and thus happened before 12,600 years bp. We also show that the Anzick-1 individual is more closely related to all indigenous American populations than to any other group. Our data are compatible with the hypothesis that Anzick-1 belonged to a population directly ancestral to many contemporary Native Americans. Finally, we find evidence of a deep divergence in Native American populations that predates the Anzick-1 individual.
http://www.ncbi.nlm.nih.gov/...
Wow! It just goes to show..it's better to make love than war.
http://www.huffingtonpost.com/...
EDIT:
* While researching this I began to wonder about the origins of east Asian (Chinese, Japanese, Vietnamese, Korean) peoples. The only creditable work on that that I found states that east Asians also came from the same stock of Homo Erectus that came out of Africa. The article was written in 2009, so new research may find that the same mixing with previous hominids that occupied the area has resulted in what is now the peoples of east Asia.
http://www.china.org.cn/...
* I decided to repost this diary for two reasons:
First: I posted this diary last weekend when many Kossacks were away at climate marches all over the world, so many may have missed it. I thank all of you who did march, for being there!!
Second: There is a need for all of us to understand how connected we are genetically, especially in light of the racism that is alive and kicking in both my country (Canada) and the US.
***Author's note: The author is not a biologist, geneticist or any other kind of "ist", so please be kind and refrain from asking really technical questions.