Tuberculosis Evolves

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Tuberculosis evolves as scientists report: "By comparing genomes of M. tuberculosis strains taken from people in Europe and Africa, Cristina Gutierrez and her colleagues at the Pasteur Institute found evidence that all modern strains have evolved from a strain that still exists in East Africa. That strain, the scientists estimate, first appeared 3 million years ago.” Their results appeared in the September 2005 PLoS Pathogens. Only Africa has endemic M. tuberculosis strains in all six families, Gagneux says, and two of those families occur nowhere else. "The most plausible theory is that TB has been in humans pretty much as long as humans have been humans," Behr says, "and the bacteria had an out-of-Africa migration with its host." "It now seems possible that the first inhabitants of the Americas already lived with an African family of M. tuberculosis but could not fight off the more virulent Euro-American strain that came across the Atlantic in the 15th and 16th centuries. Anecdotal evidence suggests that the Euro-American family is now outcompeting African strains in Africa," Gagneux says. "The best explanation for these patterns", Stone says, is that "M. tuberculosis has been evolving to infect people as people have evolved to fight it. It's an arms race," she says, "between the human immune system and TB".

Editorial Comment: So all can now see that one species of Tuberculosis has evolved into exactly the same species of Tuberculosis. And even if you allow the 3 million years they want - nothing has actually evolved at all. Reminiscent of the Emperor's new clothes isn't it. (Ref. disease, sickness, variation)

Evidence News 10 October 2007

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