Epigenetics, revisited; new exciting studies (Introduction)

by dhw, Tuesday, September 27, 2011, 14:44 (4785 days ago) @ David Turell

David has once more (actually twice!) drawn our attention to important discoveriesAVID: It appears that transposons helped mammalian evolution jump from marsupial pouches to placentas:-http://www.physorg.com/news/2011-09-invasion-genomic-parasites-triggered-modern.html-One quote in particular leaps from the page:-In the last two decades there have been dramatic changes in our understanding of how evolution works," said Gunter Wagner, the Alison Richard Professor of Ecology and Evolutionary Biology (EEB) and senior author of the paper. "We used to believe that changes only took place through small mutations in our DNA that accumulated over time. But in this case we found a huge cut-and-paste operation that altered wide areas of the genome to create large-scale morphological change."-Darwin wrote: "If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."-Modern research is rapidly uncovering more and more cases that undermine the argument for gradualism, but I still can't understand why Darwin considered it to be so fundamental. As we keep saying, he had no way of knowing what we know now (e.g. about DNA, genetics and epigenetics), but the theory as a whole ... all forms of life descending from earlier forms, with changes taking place and surviving through a process of natural selection ... stands just as firmly as it ever did. The main controversy is not about whether evolution happened, but about how, why, and over what period the changes took place.