Posted on 11/15/2006 2:09:22 PM PST by Pharmboy
An undated photograph shows the inside of the Vindija cave
in Croatia, where a leg bone from a male Neanderthal
was found and and used to sequence DNA by researchers who on
Wednesdauy said it shows that Neanderthals are truly distant
relatives of modern humans who interbred rarely, if at all,
with our own immediate ancestors. (Johannes Krause- Max-
Planck Institute of Evolutionary Anthropology/Handout/Reuters)
Researchers have sequenced DNA from the leg bone of a Neanderthal man who died 38,000 years ago and said on Wednesday it shows the Neanderthals are truly distant relatives of modern humans who interbred rarely, if at all, with our own immediate ancestors.
They estimate that modern humans and Neanderthals split from a common ancestor at least 370,000 years ago, and possibly 500,000 years ago, although we share 99.95 percent of our DNA.
"We see no evidence of mixing 40,000, 30,000 years ago in Europe. We don't exclude it, but see no evidence," Edward Rubin of the U.S. Department of Energy Joint Genome Institute in Walnut Creek, California, who led one study, told reporters.
This conflicts with some evidence from other researchers, including a team who said earlier this month that humans may have inherited a brain gene from Neanderthals.
The researchers reported their findings jointly in the journals Nature and Science.
Rubin's team used one method to isolate and sequence part of the Neanderthal's DNA, while another team, led by Svante Paabo of the Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany, used a separate method to sequence a much larger amount.
Paabo was the first scientist to find and sequence Neanderthal DNA, in 1997, and first suggested that Neanderthals did not mix with modern humans.
"I think the sequence data will serve as a DNA time machine that will tell us about biology and aspects that we will never be able to get from their bones and a limited number of associated artifacts," Rubin said.
Neanderthals and modern humans are both descended from Homo erectus, which left Africa and spread around the world about 1.5 million years ago.
LIVING SIDE BY SIDE
Neanderthals lived in Europe and the Middle East until about 30,000 years ago. Cro-Magnon people, the ancestors of modern humans, started a second wave of migration out of Africa about 10,000 years earlier.
One huge question is how closely they interacted. Paabo's and Rubin's genetic analysis both suggest there was little sexual contact, at least according to the genes from this one male found at the back of a cave in Croatia.
Paabo's team sorted through 70 Neanderthal specimens before they found a bone well-preserved enough to provide DNA. They took the tiniest samples they could to preserve the valuable bones.
They know it was a male because the DNA has a Y chromosome. Females have two X chromosomes.
Paabo's team used a gene sequencer made by 454 Life Sciences Corporation, a majority-owned subsidiary of CuraGen Corporation. He said they have refined their methods and hope to have a complete genetic sequence within two years.
They said the Neanderthal sequences are 99.95 percent identical to human DNA sequences. This compares to about a 98 percent similarity between humans and chimpanzees, who split from a common ancestor 6 million to 7 million years ago.
Three-way comparisons among the human, chimpanzee and Neanderthal genomes should shed light on what makes modern humans unique, experts agreed.
Rubin and other experts stressed that while full sequences of the human genome are available, very little is understood about what the code actually means.
"We have the book but we haven't yet read it," Rubin said.
They found, for instance, sequences linked with eye color but cannot read the code to tell what color Neanderthal eyes were.
>>truly distant relatives of modern humans who interbred rarely, if at all, with our own immediate ancestors<<
Interesting statement.
Reminds me of an old joke: "Montana! Where men are men, and sheep are nervous."
Then there are arab/camel jokes and African/monkey jokes.
IOW, if they could, they did.
That is because the 38,000 year figure, although stated as fact, is really only a deduction/opinion.
It's a quote from a Geico Insurance commercial. The commercial says that Geico Insurance is so easy to apply for, even a caveman can do it. Next scene shows an exec meeting with two cavemen in a swanky restaurant to apologize for the 'ethical' slur. One of the cavemen orders "roast duck with mango salsa" from the waiter.
I'm not sure they have sequenced enough Y-DNA to support the statement that we share 99.95 percent of our DNA. To prove that percent would take 100 percent sequencing of both human and Neanderthal DNA.
It's not an "opinion," it's the actual age of the remains, as determined by radiocarbon dating. In fact, the Vindija specimens have been subject to rigorous date testing by a number of independent teams.
Saying that radiocarbon dating is an "opinion" is as asinine as telling the police officer who pulled you over that the "80 mph" on his radar gun is an "opinion." Actually, more asinine, because radar guns are less accurate than radiocarbon dating and are not operated in controlled, laboratory conditions.
They can make the statement by taking a random sample of DNA sequenced so far and comparing it to the human genome. Obviously that number may move as more is sequenced, but as mutations tend to be pretty randomly distributed, it seems likely that that number will hold.
The cop was there.
>>Saying that radiocarbon dating is an "opinion" is as asinine as telling the police officer who pulled you over that the "80 mph" on his radar gun is an "opinion." Actually, more asinine, because radar guns are less accurate than radiocarbon dating and are not operated in controlled, laboratory conditions.<<
I disagree:
http://www.christiananswers.net/q-aig/aig-c007.html
http://www.pathlights.com/ce_encyclopedia/06dat5.htm
Also, even those who believe it is accurate only trust it back, say, 50,000 years. And that is assuming none of the issues discussed in my second link above don't hold water. Since nobody was there (unlike the cop with a radar gun), it is all deduction and opinion.
So? The radiocarbon daters are here. Both are still using technology to make measurements. Is the feed produced by a radar gun an opinion?
>>So? The radiocarbon daters are here. Both are still using technology to make measurements. Is the feed produced by a radar gun an opinion?<<
Yes, they are here in the "courtroom" but they were not "there" when the offense was committed. And yes, radar gun testimony is thrown out all the time. It really is not a very high bar.
Did you hit this:
http://www.pathlights.com/ce_encyclopedia/06dat5.htm
60,000 years, for radiocarbon dating, after which other radiometric dating methods are useful. Those include Argon-Argon, fission-track dating, Potassium-Argon, Uranium-Thorium, and many other techniques.
Since nobody was there (unlike the cop with a radar gun), it is all deduction and opinion.
Just because the cop is there doesn't mean he knows what speed it's going. He still needs to measure it. Likewise, we need to measure the age of organic substances. Both police officers and scientists use solid tools for making their measurements although, again, 14-carbon dating is inherently more reliable than a typical radar gun.
As for the links you posted, they indicate that the authors lack even a basic grasp of science.
Also, the Genesis flood would have greatly upset the carbon balance. The flood buried a huge amount of carbon, which became coal, oil, etc., lowering the total 12C in the biosphere (including the atmosphere -- plants regrowing after the flood absorb CO2, which is not replaced by the decay of the buried vegetation). Total 14C is also proportionately lowered at this time, but whereas no terrestrial process generates any more 12C, 14C is continually being produced, and at a rate which does not depend on carbon levels (it comes from nitrogen). Therefore, the 14C/12C ratio in plants/animals/the atmosphere before the flood had to be lower than what it is now.This is unimaginably idiotic. If that were the case, we should see huge discrepancies between independently known dates and radiocarbon dates for preindustrial historical remains. We don't. There goes that theory!
I know. The measurement error for radar guns is much higher than it is for radiocarbon testing, as I previously stated.
So you post some vague criticisms of radiocarbon dating, mainly from the 1950s, with a few as late as the early 1970s. Have anything a little more substantive, a little more recent? I hate to break this to you, but in 2006 there is exactly zero controversy over the legitimacy of radiocarbon and other radiometric dating within the scientific community. Often scientists argue over dates and methods, but never over the validity of the process.
Makes sense. Thanks...
Actually, the many of the arguments I posted to are pretty timeless, because they address the simple fact that we don't know exactly what the environment was like back then. It is like estimating the speed of a man running through a bus, but not taking into account the speed of the bus and just assuming it is a constant. We weren't there back then.
Too many assumptions must be made to fully trust this dating technique. Is it accurate? For the most part, probably. But its results are still only deduction and opinin and not fact, which is my point. It is by no means cast in concrete.
Here is a government site that briefly discusses reliability: http://www.esd.ornl.gov/projects/qen/nerc14C.html
That's because this type tread is usually moved into the chat forum.
Kinda like the MSM ignores stories, or places them in a back section, if the story doesn't fit the editors agenda,
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