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The Inexorable March of Convergent Evolution Continues

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One of the most powerful evidences for evolution are the similarities between species. The reason why the similarities are such powerful evidence is that a great variety of designs are possible. A wise designer certainly would make use of this great variety of possible designs but common descent is restricted to whatever is available. Consider, for example, the pentadactyl structure—five digits (four fingers and a thumb for humans) at the end of the limb structure—which is found throughout the tetrapods. The activities of this massive group of fauna include flying, grasping, climbing and crawling. Such diverse activities, evolutionists reason, should require diverse limbs. There seems to be no reason why all should need a five digit limb. Why not three digits for some, eight for others, 13 for some others, and so forth? And yet they all are endowed with five digits. Their shapes and sizes vary greatly, but nonetheless there are five digits. Obviously the pentadactyl structure must be an artefact of common descent—a suboptimal design that was handed down from a common ancestor rather than specifically designed for each species. A key premise of this argument is that a tremendous variety of designs is possible.  Read more

OT: New findings challenge assumptions about origins of life - September 13, 2013 Excerpt: This finding led to the "RNA World" hypothesis, which posits that RNA alone triggered the rise of (the first biological) life from a (primordial) sea of molecules. But for the hypothesis to be correct, ancient RNA catalysts would have had to copy multiple sets of RNA blueprints nearly as accurately as do modern-day enzymes. That's a hard sell; scientists calculate that it would take much longer than the age of the universe for randomly generated RNA molecules to evolve sufficiently to achieve the modern level of sophistication. Given Earth's age of 4.5 billion years, living systems run entirely by RNA could not have reproduced and evolved either fast or accurately enough to give rise to the vast biological complexity on Earth today. "The RNA world hypothesis is extremely unlikely," said Carter. "It would take forever." Moreover, there's no proof that such ribozymes even existed billions of years ago. To buttress the RNA World hypothesis, scientists use 21st century technology to create ribozymes that serve as catalysts. "But most of those synthetic ribozymes," Carter said, "bear little resemblance to anything anyone has ever isolated from a living system.",,, The (current) study leaves open the question of exactly how those primitive systems managed to replicate themselves—something neither the RNA World hypothesis nor the Peptide-RNA World theory can yet explain. http://phys.org/news/2013-09-assumptions-life.html bornagain77
Ha ha ha. Too funny...
We had expected to find identical changes in maybe a dozen or so genes but to see nearly 200 is incredible. We know natural selection is a potent driver of gene sequence evolution, but identifying so many examples where it produces nearly identical results in the genetic sequences of totally unrelated animals is astonishing.
SCIENTIST SUFFERING COGNITIVE DISSONANCE: "I mean, *we know* it had to be natural selection that produced this. Right?" THE UNCARING COSMOS: *crickets* SCIENTIST SUFFERING COGNITIVE DISSONANCE: "Hello? Hello? Is this thing on? Bueller? Bueller? Anyone? Anyone?..." jstanley01
Dr. Hunter, have you read The Changing Role of the Embryo in Evolutionary Thought? Highly recommended. Certain similarities cannot be explained by their utility to the organism in their environment (iow, not by selection) so in steps the theory of common descent. Other similarities are improbable given the descent hypothesis, so in steps the theory of natural selection (the features are there due to their utility to the organism, not due to common descent). Talk about a theory that is incapable of falsification! Mung

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