Contingent evolution (Introduction)

by dhw, Tuesday, June 24, 2014, 11:18 (3592 days ago) @ Balance_Maintained

DAVID: Shades of Stephan Jay Gould. How chance mutations, against the odds, advance evolution:-"Tracing these alternative evolutionary paths, the researchers discovered that the protein - the cellular receptor for the stress hormone cortisol - could not have evolved its modern-day function unless two extremely unlikely mutations happened to evolve first. These "permissive" mutations had no effect on the protein's function, but without them the protein could not tolerate the later mutations that caused it to evolve its sensitivity to cortisol. [...] "Thornton and Harms tested many thousands of variants but found none that restored the function of GR other than the historical mutations that occurred in actuality. "Among the huge numbers of alternate possible histories, there were no other permissive mutations that could have opened an evolutionary path to the modern-day GR," Thornton said.-http://www.sciencedaily.com/releases/2014/06/140618220554.htm-And fits my idea of pre-planning-TONY: So, not one single other possible solution that could work, and nature somehow 'stumbled' upon the only one that could, not once, not twice, but three times in order to come up with a meaningful change.
That has 'purposeful intent' written all over it. Something done in a specific way for a specific purpose, in this case, cortisol sensitivity.-You may both be right (says the agnostic), but you have conveniently ignored the conclusion to this article:-"It's very exciting to have been able to directly study alternative ancient histories," Thornton said. "If evolutionary history could be relaunched from ancestral starting points, we would almost certainly end up with a radically different biology from the one we have now. Unpredictable genetic events are constantly opening paths to some evolutionary outcomes and closing the paths to others, all within the biochemical systems of our cells."-You take this to indicate purpose, because your starting point is an anthropocentric view of evolution, which ... just like the theory of abiogenesis ... is pure speculation. It is just as easy to take the above as meaning that "unpredictable" chance, not purpose, has dictated the biology we have now.