Did MicroRNAs Shape the Cambrian Explosion?


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The fossil record reveals a history of life characterized by the abrupt appearance of new species followed by no change and eventual extinction in most cases. Needless to say, abrupt appearances and no change is not exactly what evolution expected. Much of this was known in Darwin's time and he figured that the fossil record was incomplete. Today such speculation doesn't work anymore. The evidence reveals even more clearly this pattern of abrupt appearances followed by stasis. As one recent paper explained:

Beginning some 555 million years ago the Earth’s biota changed in profound and fundamental ways, going from an essentially static system billions of years in existence to the one we find today, a dynamic and awesomely complex system whose origin seems to defy explanation. Part of the intrigue with the Cambrian explosion is that numerous animal phyla with very distinct body plans arrive on the scene in a geological blink of the eye, with little or no warning of what is to come in rocks that predate this interval of time.

As in Darwin's day, the fossil record does not match evolutionary expectations and evolutionists have been trying to solve the riddle. How can the empirical scientific data be explained by evolution? One new idea is to have the recently discovered microRNAs do the heavy lifting.

MicroRNAs are short snippets of DNA, about 20 nucleotides long, that help regulate protein production. The idea is that:

miRNAs might be instrumental in canalizing development such that phenotypic variation decreases through geologic time at the cost of increasing developmental precision, allowing for subsequent increases in morphological complexity.

The big words hide the fact that there is no substance to the proposal. Here is the proposal in English (my translation):

New forms abruptly appeared because evolution somehow created them. In fact, there was an abundance of these new forms, representing dozens of different designs, and many variations on each design. As luck would have it, evolution began creating microRNAs which suppressed much of that variation because, after all, microRNAs regulate protein production. So microRNAs explain the reductions in variation that follow the explosions. And, oh by the way, microRNAs also helped evolution create new wonders, not that it couldn't already, but you know, they helped.

This is the usual just-add-water view of science that prevails courtesy of evolution. Incredibly complex organisms which defy our understanding just appear now and then. They might give rise to more incredible creations, or maybe not. Meanwhile, the details of what actually happened remain a complete mystery.

For instance, the notion that microRNAs just began to proliferate on their own is absurd. They are one part of a mind-boggling regulation network. Indeed, the microRNAs themselves (which regulate protein production remember) are regulated by proteins. As new research is gradually elucidating, "MicroRNAs control the translation of mRNAs into proteins, and proteins in turn regulate the microRNAs at various levels.”

Not only is the production of microRNAs tightly controlled, but they are carefully removed from action as well, as a consequence of "a dense network of regulatory mechanisms."

But for a moment let's set all the problems aside. Let's give evolution every break and consider that this fanciful story may really be not the creation myth it appears to be, but the real thing. Taking this narrative at face value, it would mean that evolution produced the elaborate mechanisms and machinery (and sequences) of microRNAs, so that evolution then could really take off. It would be the ultimate Rube Goldberg device. Evolutionists, who are not the least abashed at presenting such tripe, are seriously telling each other that evolution created evolution. This is truly astonishing.

With each new failed expectation and each new unfounded absurd speculation, evolutionists are digging themselves deeper and deeper in their hole. Religion drives science, and it matters.

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