Posted on 07/26/2007 12:12:38 PM PDT by blam
Elephants, Human Ancestors Evolved in Synch, DNA Reveals
Hope Hamashige for National Geographic News
July 23, 2007
The tooth of a mastodon buried beneath Alaska's permafrost for many thousands of years is yielding surprising clues about the history of elephants—and humans.
A team of researchers recently extracted DNA from the tooth to put together the first complete mastodon mitochondrial genome.
The study, published in the journal PLoS Biology, significantly alters the evolutionary timeline for elephants and their relatives.
The research may put to rest a contentious debate by showing that woolly mammoths are more closely related to Asian elephants than African elephants.
Comparing the new genome with that of other animals in the elephant family also provides evidence that the elephant family diverged on roughly the same timeline that primates separated, suggesting there may have been a common cause for the splits.
"I think the divergence is the most interesting thing from this study," said lead author Michael Hofreiter, an evolutionary biologist at the Max Plank Institute for Evolutionary Anthropology in Leipzig, Germany.
Reason to Evolve
According to Hofreiter's research, African elephants diverged from mastodons about 7.6 million years ago, about the same time gorillas split from the line that gave rise to humans and chimpanzees.
Mammoths and Asian elephants speciated around 6.7 million years ago, roughly the same time humans and chimps split.
Alfred Roca is a geneticist at the Laboratory of Genomic Diversity in Frederick, Maryland, part of the U.S. National Cancer Institute. He was not involved in the new research.
He called Hofreiter's work "outstanding," noting that the research pushes the previously believed dates for the divergence of elephants by several million years.
He added that several groups of modern animals—not just elephants and humans—went through significant change during that time, the late Miocene period. (Related: "Mastodons Driven to Extinction by Tuberculosis, Fossils Suggest" [October 3, 2006].) The most widely held theory about what happened then is that climate change led to the expansion of grasslands in Africa, which fragmented habitats and spurred many species to evolve.
The new study lends further credibility to the notion that climate change can lead to evolutionary change.
"Ours is one more piece of evidence that definitely supports the idea that climate change is a key event in speciation," lead study author Hofreiter said.
Pieced Together
The new research marks a significant departure from previous studies.
Until now, scientists had reconstructed the history of the elephant family primarily using fossil evidence.
Mitochondrial DNA, which is passed on only from mother to child, provides an easy way to trace lineages and is a more accurate source of information. But its use has always been limited, because DNA in ancient fossils begins to breaks down.
Hofreiter and his colleagues, however, developed a way to piece together the genome from small samples of fragmented DNA.
They applied the technique to a mastodon tooth collected in 1999 from Alaska's Ikpikpuk River.
Radiocarbon dating of the collagen in the tooth places its age at at least 50,000 years. But researchers have concluded, based on the dating of other material from the area, that the fossil may be as old as 130,000 years old.
Never before have researchers successfully sequenced a genome from such an ancient piece of bone. Previously, Hofreiter said, the oldest fossil from which scientists were able to extract a complete genome was about 30,000 years old.
In this case, the team cut about 7 ounces (200 grams) from the root of the molar of a mastodon and extracted small fragments of the DNA from bone. By piecing together the overlapping fragments, the team was able to sequence the entire genome.
"It is amazing they were able to extract a complete genome from a bone that old," noted Anna-Sapfo Malaspinas, a researcher at the University of California, Berkeley and one of the authors who helped to analyze the sequencing after the genome was extracted.
Because the animal was encased in permafrost before being exposed to river erosion, the DNA in the mastodon was fairly well preserved, researchers say.
"It is hard, using fossils to come up with accurate dates," Roca, the geneticist, said. "But using DNA makes it easier."
Elephant in the Room
This new research may also put to rest a heated debate about the history of elephants.
"There has been controversy over whether woolly mammoths are more closely related to Asian or African elephants," said Stephen O'Brien, lab chief at the Laboratory of Genomic Diversity.
Both fossil evidence and incomplete mitochondrial genomes had previously indicated that woolly mammoths' closest relatives were African elephants.
Two years ago, however, Hofreiter was also the first to sequence a complete mitochondrial genome from a woolly mammoth. His research contradicted earlier studies because it indicated a tighter kinship to the Asian elephant.
The information extracted from the mastodon, a close relative to both mammoths and elephants, supports Hofreiter's earlier work.
According to O'Brien, studies using incomplete genome sequences from woolly mammoths are likely not as reliable.
"This is the most robust data we have seen to date."
BOO!
Looking at my in-laws, I’d say they are correct.....
Some of the Dems. make so little sense when they talk, I wonder about where their DNA came from. Especially someone such as Hillary, where people wonder if she’s human or robot, female or some other gender combination...........
“This is the most robust data we have seen to date.”
That’s not saying a hell of a lot.
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"Gods, Graves, Glyphs" PING list or GGG weekly digest
-- Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
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They found Lord Ganesh's remains?
I just hope that picture was taken with a telephoto lens! That pachyderm looks like he’s getting ready to come after you!
Is that why some women have butts he size of an elephants. :)
I’ve found it! At last, the proof of the Mammoth Conspiracy
I’ve been looking for the deep-cover conspiracy about the spate of mammoth stories recently. Now I realize it’s all aplot by AL Gore and his legions of Greens. It’s all about climate change.
“Mammoths and Asian elephants speciated around 6.7 million years ago, roughly the same time humans and chimps split.
He added that several groups of modern animals—not just elephants and humans—went through significant change during that time, the late Miocene period. The most widely held theory about what happened then is that climate change led to ...fragmented habitats and spurred many species to evolve.
The new study lends further credibility to the notion that climate change can lead to evolutionary change.”
The Theory: Accept Kyoto are you face another evolutionary change, presumably back into gorillas—or possibly into Gila Monsters.
Gee, but I’d give the world to see
that old gang of mine!
I can’t forget that old quartet
that sang “Sweet Adeline!” ( Sweet Adeline! )
Goodbye forever, old fellas an’ gals
goodbye forever, old sweethearts an’ pals
God Bless them!
Gee, but I’d give the world to see
that old gang of mine!
The only factual nugget in the entire article is that the genome sequence of the woolly mammoth was closer to that of the Asian elephant than the African elephant.
The rest of it is the usual evolutionist speculation and spin sans factual content.
I found this statement intriguing (is radio carbon dating really THAT unrealiable?):
“Radiocarbon dating of the collagen in the tooth places its age at at least 50,000 years. But researchers have concluded, based on the dating of other material from the area, that the fossil may be as old as 130,000 years old.”
The problem there being that since humans are a cancer to Gaia and evil running dog capitalist pigs have wiped out so many species, we "need" a major climate change to wipe out humans and refill empty wildlife niches.
Clearly then we should all do our part and buy bigger SUVs.
No, but by 50,000 years of age there isn't enough 14C left to accurately measure, therefore the carbon dating technique can only say that the sample is older that it can measure.
I have seen the creationists deliberately use this fact to misrepresent data, claiming that carbon dating is 'no good' because samples 'alleged' to be millions of years old are indistinguishable from samples 'alleged' to be billions of years old. And then going on to to assert (by a literal leap of faith) that this proves that the entire universe is 6000 years old.
I agree. Exactly my thoughts.
I’m willing to embrace the theory of imminent extinction of the race due to global warming—if it will get me laid as an emergency—sort of a “eat drink and make Mary for tomorrow we die” proposition.
“Radiocarbon dating of the collagen in the tooth places its age at at least 50,000 years. But researchers have concluded, based on the dating of other material from the area, that the fossil may be as old as 130,000 years old.
Radiocarbon dating is quite reliable, if used within its limits.
One of those limits is that it only extends back some 50,000 years. A few labs are working to extend that to perhaps 80,000 years, but that is still experimental.
Thus, a date based on radiocarbon dating of some item which is actually 130,000 years old might be reported as >50,000 BP.
You really need to understand science, and the details, before you go bashing it.
Here are some good links on radiocarbon and other forms of radiometric dating. If you have any questions on radiocarbon dating, let me know.
ReligiousTolerance.org Carbon-14 Dating (C-14): Beliefs of New-Earth CreationistsRadiometric Dating: A Christian Perspective by Dr. Roger C. Wiens.
This site, BiblicalChronologist.org has a series of good articles on radiocarbon dating.
Are tree-ring chronologies reliable? (The Biblical Chronologist, Vol. 5, No. 1)
Tree Ring and C14 DatingHow does the radiocarbon dating method work? (The Biblical Chronologist, Vol. 5, No. 1)
How precise is radiocarbon dating?
Is radiocarbon dating based on assumptions?
Has radiocarbon dating been invalidated by unreasonable results?
Radiocarbon WEB-info Radiocarbon Laboratory, University of Waikato, New Zealand.
Wholeheartedly agree that the anthropogenic climate change allegations by demagogues (the best known of whom is Al Gore) is an angle being worked in pretty much any partisan shilling service in the media. The whole of the new issue of Popular Science fits this category, even mentioning “An Inconvenient Truth” and Al Gore. If I see this magazine continue in this direction (and frankly, I thought it was a failing of the previous editor, now I see that it is systemic), I’m going to cancel the subscription, which has been in effect for over forty years.
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