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Old August 8th, 2012 #1
Alex Linder
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Alex Linder
Default Africa

Many human 'prototypes' coexisted in Africa

By Pallab Ghosh
Science correspondent, BBC News

Fossils from Northern Kenya show that a new species of human lived two million years ago, researchers say.

The discoveries suggests that at least three distinct species of humans co-existed in Africa.

The research adds to a growing body of evidence that runs counter to the popular perception that there was a linear evolution from monkey to ape to modern human.

The research has been published in the journal Nature.

Anthropologists have discovered three human fossils that are between 1.78 and 1.95 million years old. The specimens are of a face and two jawbones with teeth.

The finds back the view that a skull found in 1972 ago is of a separate species of human, known as Homo rudolfensis. The skull was markedly different to any others from that time. It had a relatively large brain and long flat face.

But for 40 years the skull was the only example of the creature and so it was impossible to say for sure whether the individual was an unusual specimen or a member of a new species.

With the discovery of the three new fossils researchers can say with more certainty that H.rudolfensis really was a separate type of human that existed around two million years ago alongside other species of humans.

For a long time the oldest known human ancestor was thought to be a primitive species, dating back 1.8 million years ago called Homo erectus. They had small heads, prominent brows and stood upright.

But 50 years ago, researchers discovered an even older and more primitive species of human called Homo habilis that may have coexisted with H. erectus. Now it seems H. rudolfensis was around too and raises the distinct possibility that many other species of human also existed at the time

This find is the latest in a growing body of evidence that challenges the view that our species evolved from monkeys in a smooth linear progression. Instead, according to Dr Meave Leakey of the Turkana Basin Institute in Nairobi, who led the research the find shows that there was a diversity early on in the evolution of our species.

"Our past was a diverse past," she told BBC News, "our species was evolving in the same way that other species of animals evolved. There was nothing unique about us until we began to make sophisticated stone tools."

In other groups of animals many different species evolve, each with new traits, such as plumage, or webbed feet. If the new trait is better suited to the environment then the new species thrives, if not it becomes extinct. According to Professor Chris Stringer of the Natural History Museum in London, fossil evidence is increasingly suggesting that human evolution followed the same pattern.

The march of progress had many dead ends like today's niggers

"Humans seem to have been evolving in different ways in different regions. It was almost as if nature was developing different human prototypes with different attributes, only one of which, an ancestor of our species, was ultimately successful in evolutionary terms," he said.

According to Dr Leakey, the growing body of evidence to suggest that humans evolved in the same way as other animals shows that "evolution really does work".

"It leads to amazing adaptions and amazing species and we are one of them," she said. White men are an amazing adaptation, while niggers are a dead end.

http://www.bbc.co.uk/news/science-environment-19184370
 
Old May 3rd, 2014 #3
Pamela Ross
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Pamela Ross
Default Humanity's forgotten return to Africa revealed in DNA



Quote:
03 February 2014
Call it humanity's unexpected U-turn. One of the biggest events in the history of our species is the exodus out of Africa some 65,000 years ago, the start of Homo sapiens' long march across the world.

Now a study of southern African genes shows that, unexpectedly, another migration took western Eurasian DNA back to the very southern tip of the continent 3000 years ago.

According to conventional thinking, the Khoisan tribes of southern Africa, have lived in near-isolation from the rest of humanity for thousands of years. In fact, the study shows that some of their DNA matches most closely people from modern-day southern Europe, including Spain and Italy.

Because Eurasian people also carry traces of Neanderthal DNA, the finding also shows for the first time that genetic material from our extinct cousin may be widespread in African populations.

The Khoisan tribes of southern Africa are hunter-gatherers and pastoralists who speak unique click languages. Their extraordinarily diverse gene pool split from everyone else's before the African exodus.


Ancient lineages
"These are very special, isolated populations, carrying what are probably the most ancient lineages in human populations today," says David Reich of Harvard University. "For a lot of our genetic studies we had treated them as groups that had split from all other present-day humans before they had split from each other."

So he and his colleagues were not expecting to find signs of western Eurasian genes in 32 individuals belonging to a variety of Khoisan tribes. "I think we were shocked," says Reich.

The unexpected snippets of DNA most resembled sequences from southern Europeans, including Sardinians, Italians and people from the Basque region (see "Back to Africa but from where?").

Dating methods suggested they made their way into the Khoisan DNA sometime between 900 and 1800 years ago well before known European contact with southern Africa (see map).

Archaeological and linguistic studies of the region can make sense of the discovery. They suggest that a subset of the Khoisan, known as the Khoe-Kwadi speakers, arrived in southern Africa from east Africa around 2200 years ago. Khoe-Kwadi speakers were and remain pastoralists who make their living from herding cows and sheep. The suggestion is that they introduced herding to a region that was otherwise dominated by hunter-gatherers.

Khoe-Kwadi tribes

Reich and his team found that the proportion of Eurasian DNA was highest in Khoe-Kwadi tribes, who have up to 14 per cent of western Eurasian ancestry. What is more, when they looked at the east African tribes from which the Khoe-Kwadi descended, they found a much stronger proportion of Eurasian DNA up to 50 per cent.

That result confirms a 2012 study by Luca Pagani of the Wellcome Trust Sanger Institute in Hinxton, UK, which found non-African genes in people living in Ethiopia.

Both the 2012 study and this week's new results show that the Eurasian genes made their way into east African genomes around 3000 years ago. About a millennium later, the ancestors of the Khoe-Kwadi headed south, carrying a weaker signal of the Eurasian DNA into southern Africa.

The cultural implications are complex and potentially uncomfortably close to European colonial themes. "I actually am not sure there's any population that doesn't have west Eurasian [DNA]," says Reich.

"These populations were always thought to be pristine hunter-gatherers who had not interacted with anyone for millennia," says Reich's collaborator, linguist Brigitte Pakendorf of the University of Lyon in France. "Well, no. Just like the rest of the world, Africa had population movements too. There was simply no writing, no Romans or Greeks to document it."

Twist in tale

There's one more twist to the tale. In 2010 a research team including Reich published the first draft genome of a Neanderthal. Comparisons with living humans revealed traces of Neanderthal DNA in all humans with one notable exception: sub-Saharan peoples like the Yoruba and Khoisan.

That made sense. After early humans migrated out of Africa around 60,000 years ago, they bumped into Neanderthals somewhere in what is now the Middle East. Some got rather cosy with each other. As their descendants spread across the world to Europe, Asia and eventually the Americas, they spread bits of Neanderthal DNA along with their own genes. But because those descendants did not move back into Africa until historical times, most of this continent remained a Neanderthal DNA-free zone.

Or so it seemed at the time. Now it appears that the Back to Africa migration 3000 years ago carried a weak Neanderthal genetic signal deep into the homeland.
Indeed one of Reich's analyses, published last month, found Neanderthal traces in Yoruba DNA (Nature, DOI: 10.1038/nature12886).

In other words, not only is western Eurasian DNA ancestry a global phenomenon, so is having a bit of Neanderthal living on inside you.

Journal reference: PNAS, DOI: 10.1073/pnas.1313787111


Back to Africa but from where?

Reich and his colleagues found that DNA sequences in the Khoisan people most closely resemble some found in people who today live in southern Europe. That, however, does not mean the migration back to Africa started in Italy or Spain. More likely, the migration began in what is now the Middle East.

We know that southern Europeans can trace their ancestry to the Middle East.
However, in the thousands of years since they and the ancestors of the Khoisan left the region, it has experienced several waves of immigration. These waves have had a significant effect on the genes of people living in the Middle East today, and and means southern Europeans are much closer to the original inhabitants of the Levant than modern-day Middle Easterners
http://www.newscientist.com/article/...l#.UyZI41IaKQP
 
Old May 3rd, 2014 #4
Pamela Ross
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Pamela Ross
Default Ancient African cattle first domesticated in Middle East, study reveals

Quote:
March 28, 2014

Geneticist and anthropologists previously suspected that ancient Africans domesticated cattle native to the African continent nearly 10,000 years ago. Now, a team of University of Missouri researchers has completed the genetic history of 134 cattle breeds from around the world. In the process of completing this history, they found that ancient domesticated African cattle originated in the "Fertile Crescent," a region that covered modern day Iraq, Jordan, Syria and Israel.
(see previous post: ''We know that southern Europeans can trace their ancestry to the Middle East'')

Lead researcher Jared Decker, an assistant professor of animal science in the MU College of Agriculture, Food and Natural Resources, says the genetics of these African cattle breeds are similar to those of cattle first domesticated in the Middle East nearly 10,000 years ago, proving that those cattle were brought to Africa as farmers migrated south. Those cattle then interbred with wild cattle, or aurochs, which were native to the region, and changed their genetic makeup enough to confuse geneticists.

In their study published in PLOS Genetics, Decker and a team of international researchers compared the similarities and differences among the genetics of many different cattle breeds to determine how the breeds are related. Their research found mixing of native cattle in Indonesia with imports from India, European and African cattle in Italy and Spain, and European and Asian cattle in Korea and Japan. The MU researchers also determined that unique American cattle breeds, such as Texas longhorns, are the result of breeding between Spanish cattle, transported from Europe by explorers in the 16th century, and breeds of Zebu, or Brahman cattle from India imported into the U.S. from Brazil in the late 1800s. Decker says these discoveries help advance genetics and uncover important information about human history.

"In many ways, the history of cattle genetics mirrors human history," Decker said. "In the case of African cattle, anthropologists and geneticists used to suspect that domesticated African cattle were native to the continent, when in fact, they were brought by migrating peoples thousands of years ago. By better understanding the history of the animals we domesticate, we can better understand ourselves."

Decker also said that cattle breeding is important for animal farmers looking to maximize their herds' meat and dairy production. He says that understanding the genetic history of cattle breeds is important when looking for solutions to agricultural issues.

"Now that we have this more complete genetic history of cattle worldwide, we can better understand the diversity of the species," Decker said. "By understanding the variations present, we can improve cattle for agricultural purposes, whether that is through breeding more disease-resistant animals or finding ways to increase dairy or beef production."
http://www.sciencedaily.com/releases...0328121025.htm
 
Old May 4th, 2014 #5
Alex Linder
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Default

I like to think of myself as a post-human prototype. Is that so wrong?
 
Old May 16th, 2014 #6
Pamela Ross
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Join Date: Apr 2014
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Default

Quote:

Call it humanity's unexpected U-turn.
One of the biggest events in the history of our species
is the exodus out of Africa some 65,000 years ago,
the start of Homo sapiens' long march across the world.
Now a study of southern African genes shows that, unexpectedly,
another migration took western Eurasian DNA back
to the very southern tip of the continent 3000 years ago.

http://www.newscientist.com/article/...l#.U3ZhSdiKDIX


Quote:
Bantu migration


1 = 2000–1500 BC origin
2 = ca.1500 BC first migrations
2.a = Eastern Bantu, 2.b = Western Bantu
3 = 1000–500 BC Urewe nucleus of Eastern Bantu
4–7 = southward advance
9 = 500 BC–0 Congo nucleus
10 = 0–1000 AD last phase
[12][13][14

http://en.wikipedia.org/wiki/Bantu_expansion
So, Bantus aren't indigenous people of East Africa.
 
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