Apparently he's now a devotee of makeup, barbells, and plastic surgery.
Posted on 10/28/2007 4:03:27 PM PDT by Lessismore
What would it have been like to meet a Neandertal? Researchers have hypothesized answers for decades, seeking to put flesh on ancient bones. But fossils are silent on many traits, from hair and skin color to speech and personality.
Personality will have to wait, but in a paper published online in Science this week (www.sciencemag.org/cgi/content/abstract/1147417), an international team announces that it has extracted a pigmentation gene, mc1r, from the bones of two Neandertals. The researchers conclude that at least some Neandertals had pale skin and red hair, similar to some of the Homo sapiens who today inhabit their European homeland. The paper comes on the heels of one that used similar techniques to show that Neandertals shared the modern human form of the only gene so far known to influence human speech, FOXP2. Although researchers are working to sequence the entire Neandertal genome (Science, 17 November 2006, p. 1068), these are the first specific nuclear genes to be retrieved. "These are the two genes you'd most like to see from a Neandertal," explains Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who led the FOXP2 study.
The mc1r paper is "logical, elegant, and convincing," says anthropologist Nina Jablonski of Pennsylvania State University in University Park. "It's a great paper," agrees molecular geneticist and pigmentation expert Rick Sturm of the University of Queensland in St. Lucia, Australia.
Many of the Neandertals cavorting in museum dioramas around the world already have pale skin or red hair, because anthropologists have long predicted this coloration on the basis of evolutionary theory. The dark skin beneficial in Africa offers no advantage at high latitudes, and in cloudy Europe, pale skin facilitates vitamin D production, Jablonski says. But there was no proof of Neandertals' looks until a team led by Carles Lalueza-Fox of the University of Barcelona in Spain and Holger Rämpler of the University of Leipzig in Germany set out to retrieve the mc1r gene from a 43,000-year-old Neandertal from El Sidrón, Spain, and a 50,000-year-old specimen from Monti Lessini, Italy.
MC1R is a cell membrane receptor that helps regulate the balance between red-and-yellow-colored pheomelanin and black-and-brown-colored eumelanin. Living people with variations that make the receptor work poorly tend to have red hair and pale skin, although other pigmentation genes also have strong effects (Science, 2 March, p. 1215).
Using the polymerase chain reaction (PCR) to target and amplify the gene, the researchers found a point mutation not seen in living humans. They checked about 3700 people, including everyone involved in the project, to be sure that the variant was unique to Neandertals. Next, they explored the variant's function by expressing it in human cells and found that it impaired the receptor's activity. "If you have a variant with this low action in modern humans, you get classically Irish-looking red hair and pale skin" in homozygotes, people with two copies of the variant, says team member Michael Hofreiter of the Max Planck Institute in Leipzig. The researchers calculate that at least 1 in 100 Neandertals would have been homozygotes. Thus Neandertals and Homo sapiens in Europe followed independent evolutionary paths to a similar phenotype, Lalueza-Fox says. "I'm convinced that what they're saying is real," says Sturm, who has used similar functional assays to check mc1r variants in living people. Lalueza-Fox adds that Neandertals may have carried a variety of changes in mc1r, as we do, and so may have had a spectrum of skin and hair colors.
Pääbo and colleagues also used targeted PCR to isolate the FOXP2 gene. They chose FOXP2 because people with mutations in the gene have impaired speech. Pääbo's team had previously traced the gene in living people and suggested that the unique human variant was selected relatively recently, less than 200,000 years ago--long after Neandertals and modern humans had diverged (Science, 16 August 2002, p. 1105). The implication was that Neandertals lacked the modern human form, Pääbo says.
But to their surprise, that's not what they found when they sequenced the gene from two bones from El Sidrón, where Lalueza-Fox runs a "clean" excavation for DNA analysis. Both bones carried the modern human version of FOXP2. That doesn't necessarily mean Neandertals spoke as we do, because many genes presumably influence speech. But "from the point of view of the one gene we know, there's nothing to say that Neandertals were different from us" in their language abilities, Pääbo says.
Because the Neandertal FOXP2 gene matched that found in living people, Pääbo's team used extra controls to try to rule out contamination with modern human DNA. For example, they sequenced the Neandertal Y chromosome and found that it differed from that of living men at five key sites. No contamination of the Y chromosome strengthens the case that the FOXP2 result is real, Pääbo says.
The Y chromosome finding also argues against interbreeding between Neandertals and the modern humans then entering Europe. "I find it paradoxical in some ways," says Lalueza-Fox, who is an author of both studies. "The papers make Neandertals more like modern Europeans, with light skin and hair color and language abilities, and yet there are no signs of interbreeding with modern humans."
But others aren't yet ready to concede that either contamination or mixing has been completely ruled out. "The additional controls give one more confidence that contamination is not a problem, but we can't be 100% sure," says evolutionary geneticist Jeff Wall of the University of California, San Francisco, who in August reported what he saw as contamination in Pääbo's group's bulk Neandertal sequencing (ScienceNOW, 29 August, sciencenow.sciencemag.org/cgi/content/full/2007/829/4).
Wall adds that if the FOXP2result is real, it's possible that Neandertals acquired the human FOXP2variant by mixing. "If there was admixture, it wasn't very much. But we can't tell if there was a small amount." Pääbo says he can't rule out that scenario but considers it "unlikely," given the genetic data so far.
:-)
Nothing so crude, I'd never dream of it! Besides, "you're an a$$hole" should only be spoken in English to get the full effect.:)
Just click this link, scroll down to 'May the cat eat you and the devil eat the cat', and you can hear it in 3 different Gaelic accents. Don't ask me why they say that, these are the Irish, y'know.
Apparently he's now a devotee of makeup, barbells, and plastic surgery.
Oh, sorry. Silly me!
susie
It’s not a new hypothesis. What’s new is genetic evidence supporting it — before, it was a matterof inference based on the pigmentation of modern populations in the area.
The Neandertal EnigmaFrayer's own reading of the record reveals a number of overlooked traits that clearly and specifically link the Neandertals to the Cro-Magnons. One such trait is the shape of the opening of the nerve canal in the lower jaw, a spot where dentists often give a pain-blocking injection. In many Neandertal, the upper portion of the opening is covered by a broad bony ridge, a curious feature also carried by a significant number of Cro-Magnons. But none of the alleged 'ancestors of us all' fossils from Africa have it, and it is extremely rare in modern people outside Europe." [pp 126-127]
by James Shreeve
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Blast from the Past. Also a duplicate, if memory serves. Showed up in a search for something else. Just adding to the catalog, not sending a general distribution. |
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GENOMEThe different kind blood group you have determines your susceptibility to certain diseases. For example, people with A blood are less likely to get diarrhoea than people with B blood. People with O blood are more susceptible to getting diarrhoea than anybody else. People with AB blood are virtually immune to diarrhoea because of their resistance. Nobody really yet knows how AB genotype protects them from this disease. "Since people with the O blood are the most susceptible to the disease, shouldn't they die out according to natural selection?' you are probably asking. That is true but there are a couple of things that keep the O group alive and one of them is malaria. People with O blood are more resistant to malaria than other groups. Another thing is that the O group is less likely to get certain cancers. These benefits cancel out the negative effect that the O blood group has on the diarrhoea disease so, this balance has kept the group from disappearing.
the autobiography of
a species in 23 chapters
by Matt Ridley
(from chap 9)
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