Reverend AtheiStar Posted November 20, 2006 Share Posted November 20, 2006 http://www.world-science.net/othernews/061...neanderthal.htm Neanderthal DNA partially sequenced Nov. 16, 2006 Courtesy Lawrence Berkeley National Laboratory and World Science staff Scientists have written out a small fraction of the Neanderthal genetic code, using it to map out when the stocky human cousins diverged from our own species. The scientists also concluded that Neanderthals mated little if at all with the forebears of modern humans—contradicting another recent study, and adding a new page to a debate that has seen flip-flopping conclusions in recent years. ------------------------------------------------------------------------------ Analysis of genomic DNA from fossilized Neanderthal bones indicated that Homo sapiens and Homo neanderthalensis last shared a common ancestor about 700,000 years ago, scientists say. The two hominids split into into separate species around 400,000 years ago, they add. (Courtesy LBL) -------------------------------------------------------------------------------- Neanderthals are the closest hominid relatives of modern humans. The two species co-existed in Europe and western Asia as late as 30,000 years ago. Scientists with the U.S. Energy Department’s Lawrence Berkeley National Laboratory in Berkeley, Calif., and the Joint Genome Institute in Walnut Creek, Calif. sequenced DNA from Neanderthal fossils. The results indicate their genomes were at least 99.5-percent identical to ours, the researchers said. Based on these early findings, the species shared a common ancestor about 700,000 years ago, wrote the investigators in the Nov. 17 issue of the research journal Science. Until now, knowledge of Neanderthals came from “limited number of bony remains and associated artifacts that are available in hard-to-access museum collections and field sites,” said Edward Rubin, director of the institute and of the laboratory’s Genomics Division, and lead author of the study. That will change, he added. “In the near future, anthropologists will be able to develop hypotheses about our extinct ancestors through the scanning of billions of base pairs of DNA sequences available on the web.” A base pair is a “letter” of genetic code. In 1856, a partial hominid skeleton turned up at the Feldhofer Cave in Germany’s Neander Valley. The skeleton would be dubbed Neanderthal Man. It generated public curiosity and scientific debate that continue today. Artist's concept of a Neanderthal. (Courtesy Science) In the late 1990s, scientists began using genetic technology to study Neanderthals. Research led by Svante Pääbo, now of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, found that Neanderthals were cousins rather than ancestors of modern humans. In the new work, Rubin and colleagues extracted the DNA in the thigh bone of a 38,000-year-old male Neanderthal from Vindija, Croatia. They recovered 65,250 base pairs of Neanderthal DNA, out of a total of an estimated three billion base pairs. Comparing Neanderthal to human and chimpanzee genomes showed that in many places the Neanderthal code matched chimp DNA but not human, Rubin said. “This enabled us to calculate for the first time when in pre-history Homo sapiens and Homo neanderthalensis [Neanderthals] coalesced to a single genome,” he added. The analysis found that the common genetic ancestor of Neanderthal and modern humans lived about 706,000 years ago, he continued. This would be the time when the two lineages began to diverge, the researchers said; the final split, though, came some 330,000 years later. Rubin and his colleagues said they also shed new light on the long-standing question of whether Neanderthals and humans mated during the thousands of years the two species cohabitated parts of Europe. Some scientists have suggested that rather than die out, Neanderthals as a species were bred out of existence by the overwhelming populations of Homo sapiens. Said Rubin, “While unable to definitively conclude that interbreeding between the two species of humans did not occur, analysis... suggests the low likelihood of it having occurred at any appreciable level.” Past Neanderthal gene studies were based on so-called mitochondrial DNA, genetic material that lies outside the cell nucleus, Rubin said. This type tends to stay better-preserved, he added, but provides limited information because the vast majority of the genome is in the nucleus. His study focused on this “nuclear” DNA. “If you want to understand how traits like language and cognition are encoded, you have to study nuclear DNA,” said James Noonan of the Berkeley Lab and Joint Genome Institute, a member of the research team. Link to comment Share on other sites More sharing options...
Mr. XC Posted November 20, 2006 Share Posted November 20, 2006 Thanks for finding and sharing this. I found a couple of other articles that are related for anyone interested: http://news.bbc.co.uk/1/hi/sci/tech/6146908.stm http://news.nationalgeographic.com/news/20...erthal-dna.html Link to comment Share on other sites More sharing options...
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