Tag: science
Icons of Evolution 10th Anniversary: Archeopteryx
Subtle-But Important-Functions of Junk-DNA
The December 17, 2010 issue of Science has yet another article explaining why the concept of “junk”-DNA should no longer be given much credence: It used to seem so straightforward. DNA told the body how to build proteins. The instructions came in chapters called genes. Strands of DNA’s chemical cousin RNA served as molecular messengers, carrying orders to the cells’ protein factories and translating them into action. Between the genes lay long stretches of “junk DNA,” incoherent, useless, and inert. That was then. In fact, gene regulation has turned out to be a surprisingly complex process governed by various types of regulatory DNA, which may lie deep in the wilderness of supposed “junk.” Far from being humble messengers, RNAs of Read More ›
Methinks New PNAS Paper Is Like a Weasel
A paper by Wilf and Ewens recently published online in the Proceedings of the National Academy of Sciences, titled “There’s plenty of time for evolution,” reads like a printed version of Groundhog Day — the classic movie where comedian Bill Murray keeps awakening to find it’s the same day again. The paper’s authors sniff at unnamed benighted folks who think there hasn’t been enough time for (Darwinian) evolution to build the complexity we see in life. Not so, they protest. Why, all one has to do to see the light is to use the right mathematical model: “After guessing each of the letters, we are told which (if any) of the guessed letters are correct, and then those letters are Read More ›
Icons of Evolution 10th Anniversary: Paul Nelson
At 4:38 of this interview, Paul Nelson says that the Miller-Urey experiment is incorrectly interpreted by textbooks as having “synthesized life.” What he meant to say was “the building blocks of life.” Dr. Nelson regrets the error.
Michael Behe’s “First Rule of Adaptive Evolution” Could Undermine the Evolution of Functional Coding Elements
After reviewing the effects of mutations upon Functional Coding ElemenTs (FCTs), Michael Behe’s recent review article in Quarterly Review of Biology, “Experimental Evolution, Loss-of-Function Mutations and ‘The First Rule of Adaptive Evolution’,” offers some conclusions. In particular, as the title suggests, Behe introduces a rule of thumb he calls the “The First Rule of Adaptive Evolution”: “Break or blunt any functional coded element whose loss would yield a net fitness gain.” In essence, what Behe means is that mutations that cause loss-of-FCT are going to be far more likely and thus far more common than those which gain a functional coding element. In fact, he writes: “the rate of appearance of an adaptive mutation that would arise from the diminishment Read More ›