Shotgun 1 #1 February 21, 2006 Interesting article in this month's Discover... "A monstrous discovery suggests that viruses, long regarded as lowly evolutionary latecomers, may have been the precursors of all life on Earth"... http://www.discover.com/issues/mar-06/cover/?page=1 Quote.......The discovery of Mimivirus lends weight to one of the more compelling theories discussed at Les Treilles. Back when the three domains of life were emerging, a large DNA virus very much like Mimi may have made its way inside a bacterium or an archaean and, rather than killing it, harmlessly persisted there. The eukaryotic cell nucleus and large, complex DNA viruses like Mimi share a compelling number of biological traits. They both replicate in the cell cytoplasm, and on doing so, each uses the same machinery within the cytoplasm to form a new membrane around itself. They both have certain enzymes for capping messenger RNA, and they both have linear chromosomes rather than the circular ones typically found in a bacterium. "If this is true," Forterre has said of the viral-nucleus hypothesis, "then we are all basically descended from viruses."....... Quote Share this post Link to post Share on other sites
billvon 3,154 #2 February 21, 2006 That's somewhat similar to the RNA hypothesis, in which early strands of RNA gained the ability to self-replicate and gradually accreted the beginnings of a cell around themselves. We can reproduce that process in a lab. The idea that they "co-opted" a cell is similar to the mechanism by which mitochondria likely came to exist in our cells - a larger cell 'swallowed' a mitochondria-like bacterium and discovered that it did a much better job than the original cell at converting food into energy. Quote Share this post Link to post Share on other sites
