Daniel Smith
Posts: 970
Joined: Sep. 2007
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| Quote (C.J.O'Brien @ Oct. 10 2007,12:35) | That there is a certain kind of elegance to biochemical processes is not in question. They work well enough to have sustained evolving life on Earth for billions of years, and are perfectly capable of supporting the functions of big, complex animals like ourselves. So I am not saying that they barely "get the job done." I am saying, though, that all of the highly-touted complexity of the cell, when it is actually investigated, not simply remarked upon, seems to owe its existence to a maddeningly short-sighted designer --one that seems incabable of building a structure or pathway using anything other than pre-existing components, often themselves integral parts of other, fully functioning systems. But you challenged me for examples.
Here is Ken Miller on the vertebrate blood-clotting cascade
Here is a TalkOrigins summary of several articles on the evolution of the Krebs Cycle
Here is an abstract of a Science paper on the evolution of a steroid-hormone receptor |
The articles and abstracts you cite are just explanations of how such systems theoretically could have evolved - not evidence that these systems are cobbled together "Rube Goldberg" type systems.
I found this item from the article on blood clotting interesting: | Quote | If the modern fibrinogen gene really was recruited from a duplicated ancestral gene, one that had nothing to do with blood clotting, then we ought to be able to find a fibrinogen-like gene in an animal that does not possess the vertebrate clotting pathway. In other words, we ought to be able to find a non-clotting fibrinogen protein in an invertebrate. That's a mighty bold prediction, because if it could not be found, it would cast Doolittle's whole evolutionary scheme into doubt.
Not to worry. In 1990, Xun Yu and Doolittle won their own bet, finding a fibrinogen-like sequence in the sea cucumber, an echinoderm. The vertebrate fibrinogen gene, just like genes for the other proteins of the clotting sequence, was formed by the duplication and modification of pre-existing genes. |
This prediction does not seem that "bold" to me - since we already know that convergent evolution produces analogous sequences in unrelated animals. In fact, I'll be even bolder and predict that you can take any gene and find something "like it" somewhere in some unrelated organism's genome.
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"If we all worked on the assumption that what is accepted as true is really true, there would be little hope of advance." Orville Wright
"The presence or absence of a creative super-intelligence is unequivocally a scientific question." Richard Dawkins
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