Theory on origins of man gets genetic overhaul

Modern man evolved from a mixture of ancient African immigrants and primitive humans elsewhere, suggests a genetic analysis released today that raises new questions about long-held theories of human origins.

For decades, archaeologists, paleontologists and genetics experts have argued about the evolution of modern man. While the various disciplines had remained divided, the weight of genetic studies had recently favored the "Out of Africa" theory. It says modern-looking humans originated in Africa and spread worldwide about 100,000 years ago, slowly replacing Neanderthals and other evolutionary dead-end humans elsewhere.

Now, however, genetics expert Alan Templeton of Washington University in St. Louis reports that a wide-ranging sample of 11 different types of DNA found in human populations today shows archaic humans, known as Homo erectus to scientists, freely mixed their genes among African, European and Asian populations for the past 600,000 years.

Rather than being wiped out by African immigrants, genes from those archaic humans appear in eight of the DNA regions in the study, Templeton says.

And rather than one migration out of Africa, he reports in the journal Nature, at least two such expansions took place, one about 600,000 years ago and the other about 95,000 years ago, based on the study's DNA samples.

"The most recent out-of-Africa expansion event was not a replacement event," Templeton says.

While most of humanity's genetic legacy traces from Africa, he says, "over a long time, there was sufficient genetic interchange to ensure that all humanity evolved as a single species."

Proponents of the "multiregional" theory of human evolution, which says modern Homo sapiens sprang from the shared evolution of more primitive Homo erectus humans worldwide, can feel "vindication" in the results, paleontologist Milford Wolpoff of the University of Michigan-Ann Arbor says.

Past genetic studies of human origins examined too few genes to reveal the influence of archaic humans, Wolpoff says.

But in a commentary published along with the study, geneticist Rebecca Cann of the University of Hawaii-Manoa cautions that "perhaps Templeton was over-ambitious in the scale of his analysis." Some of the genetic samples in the study came from only 35 people, she notes, too few to be definitive.

And despite calling the paper a "significant advance," paleontologist Christopher Stringer of London's Natural History Museum suggests the fossil record still supports the notion that modern-looking humans evolved solely in Africa.

Perhaps human genes diversified in Africa over the past 600,000 years and were carried outward by waves of immigrants starting about 130,000 years ago, he suggests. Wolpoff says the study won't settle the long-running disagreement between the various human-origins camps, but he's confident that future studies will support his views. "The next generation of scientists will forget this one and move on to their own big debates," he says.

"In a new genetic study of modern human origins, an American scientist has found what he says is substantial evidence that could reshape the prevailing "out of Africa" theory. Among his findings, he says, is the likelihood that genes from Neanderthals and other species live on in present-day humans.

The problem with this "study" which the evolutionists are spamming all over FR is that it is total bunk. Except for two samples of Neanderthal DNA which were found quite fortuitously and prove conclusively that they were not human, we do not have any DNA of these creatures which according to evolutionists are our ancestors. Fossilized bones do not provide DNA for examination.

You can trace connections with DNA if you know the DNA of the two species being compared, however you cannot compare the DNA of two species for which you do not have the DNA of one just like you cannot compare an apple to an orange if you have never seen an orange.

What these two articles show is the total dishonesty of both the NY Times and Nature. They know better. They know they are publicizing a humongous lie. They are whores of evolution. That evolutionists so willingly make up, publish and spread such lies, shows quite clearly both that evolution is not science and that evolution is a blatant lie.

You are setting up straw men to knock them down. This study is based upon deductive reasoning about the timing of DNA entry into the human genome, not about how similar or dissimilar our genome is to the Neandertals. There can be no question that archaic DNA from earlier Homo is in our genes--we did not spring full-born from the head of Zeus. We had a history. Also, see below from the BBC:

DNA clues to Neanderthals

Scientists have analysed the DNA of a third Neanderthal in an attempt to shed light on the genetic history of early humans.

The results suggest that, like modern humans, Neanderthals expanded from a relatively small number of individuals.

And there is no evidence to indicate that Neanderthals interbred with modern humans, something that has always been a bone of contention among experts. The DNA was extracted from remains of a Neanderthal found in Vindija Cave, Croatia.

So far, only two other samples of DNA from Neanderthal bones have been analysed. One came from fossils found in Feldhofer Cave, western Germany, the other from a Neanderthal child found in Mezmaiskaya Cave in the northern Caucasus.

Genetic diversity

The researchers compared regions of the Neanderthals' DNA with those of humans, chimps and gorillas. "It allows us to start to say something about how much genetic variation there seems to have been among Neanderthals," said team leader Svante Paabo, Professor of Genetics and Evolutionary Biology at the Max Planck Institute for Evolutionary Anthropology, Liepzig, Germany.

"The major question is if they were more like humans in having very little genetic differences within the group, or much variation like chimpanzees and the other apes," he told BBC News Online. "Although three individuals is still a very small number of individuals, the results suggest that they were more like us in having little variation rather than like the apes in having a lot.

"This may indicate that they had expanded from a smaller population as seems to be the case for modern humans, but that they represent an earlier expansion."

Interbreeding unlikely

The DNA sequence of Neanderthals could also solve another age-old mystery: whether interbreeding between Neanderthals and modern humans may have taken place.

Professor Paabo said: "Although we cannot exclude some degree of interbreeding, these results give no evidence that interbreeding took place. "We want to study more Neanderthals as well as early modern humans to begin to reconstruct the genetic history of both groups at the time when they were contemporaneous with each other."

Neanderthals lived in Europe between about 130,000 and 30,000 years ago.

The bones used in the new study were dated to at least 42,000 years ago.

Last Neanderthals

Professor Chris Stringer, Head of Human Origins at the Natural History Museum, London, UK, said the three DNA studies gave scientists a glimpse of the genetic make-up of the Neanderthals. "Neanderthals are different from modern humans - they are as different from Europeans as they are from Africans or Australians in this DNA," he said.

"Now with three of them you can start to build up a picture of their own variation and they are showing their own variation which is comparable to that of modern humans."

He said the genetic diversity of Neanderthals suggested that they declined in numbers at some point in history, perhaps because of climatic change. But unlike modern humans, they never recovered fully. "The Neanderthals did recover too but they became extinct.

"They were never in huge numbers. Their recovery would have been a gradual recovery from some kind of bottleneck."

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