by Brian Thomas, M.S.
The evolutionary community has been buzzing over bacteria’s new ability to obtain citrate, a carbon-containing chemical, from their environment and use it as a food source. Some say this confirms evolution in action but what if the bacteria were designed to modify themselves? That might disappoint evolution enthusiasts.
Microbiologist Richard Lenski is renowned for managing the most extensive and intensive evolutionary experiment on bacteria. Over several decades, his team has tracked changes in over 40,000 generations of E. coli. Although these bacteria normally can’t import citrate in the presence of oxygen, after 30,000 generations, some of his did. Did the bacteria invent a new mechanism to import citrate? If so, then how?
To verify that this new trait represents the kind of evolution that can change a microbe into a man, researchers needed to describe exactly what went on behind the scenes. The highly anticipated details appear in the journal Nature.1
Prior to this new trait, none of the other observed changes that Lenski and his team had tracked showed that the bacteria evolved into a different basic kind—they were all still E. coli. And so far, none of those changes specified any new functional coding, which would occur the same as if chance-based phenomena could write a computer program. Did the strain of E. coli that acquired the new ability to import citrate—called Cit+—construct new functional, biochemical machinery by chance-base mutations?
In 2010, biochemist Michael Behe reviewed 12 new phenotypes, which are outward expressions of genetic coding, that Lenski’s E. coli displayed from 1994 to 2008.2 Behe categorized the known genetics producing each new bacterial phenotypes as either losing, shuffling, or gaining what he called “functional coded elements,” which include genes and gene promoters. All the known changes in the bacteria were either a loss or reorganization of pre-existing functional coded elements. None of the new phenotypes came from a gain of functional coded elements, and yet this is what molecules-to-man evolution requires….
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