Evolution at Work

clipped from arstechnica.com Ars covered the research earlier this month, when a paper reporting it was first published in the Proceedings of the National Academies of Science. Richard Lenski and his colleagues have been conducting a long-term experiment in bacterial evolution, one that has encompassed over 30,000 generations of bacteria going back over 20 years. Many of the bacteria have evolved the ability to better utilize the sugar available in their cultures, but one strain underwent at least three distinct changes (at generation 27,000, 31,000 and 33,000) that enabled them to access citrate present in the medium—something their parents were incapable of. Lenski saved samples of every culture at intervals of 500 generations, and his paper suggested his lab was going back and sequencing the genomes of the intermediaries to try to find out the genetic basis for the evolution of this new trait.

This is a fascinating bit of scientific research. The beauty of using bacteria to study evolution is that their generations turn over so quickly. It's like watching more complex species over millions of years; in addition you can control the conditions so the experiment is more elegant than what's seen in evolution in the wild. And sequencing the genome to find out where those changes occur will give us a better understanding of how such changes do occur in the wild. It's hard to look at this and ignore the fact that these bacteria are evolving.

Equally fascinating is the reaction of certain conservatives to its publication. Conservapedia, a wiki formed in reaction to the free-for-all atmosphere of Wikipedia editorial meetings, has decided this whole experiment is a hoax. Ars Technica has a whole run-down of the ridiculous drama involved, which includes not actually reading the openly published data and demanding the data behind the data, which is okay, if you have a clue about how to crunch it yourself. That's actually what science is all about: duplicating results to verify hypotheses. Non-duplicable results are extremely suspect (see the brouhaha over cold fusion), but somehow I don't see Conservapedia's people being able to carry off either that argument or the experiment itself. Crying hoax in this case is just an attempt to discredit the researcher—a cheap shot, to say the least, and the sure sign of a sore loser.

One of my friends recounted a conversation she had with her conservative, creationist parents about the problem of antibiotic-resistant bacteria, a problem they were very concerned about. When she pointed out that the bacteria have evolved this resistance over time, they were nonplussed. How could that be, if evolution were untrue? On the other hand, if they didn't evolve that resistance, how had it happened?

Occam's razor says . . . evolution. It's a generally elegant paradigm, even if the fine details are somewhat sketchy. And that's what makes the bacteria research so interesting: genome sequencing will show without a doubt that beneficial genomic changes—mutations—do happen and perhaps at a greater rate than we may have suspected.

But True Believer's don't have much use for Occam's razor, and evolution upsets their notions of divine creation. I see this as a failure of imagination, if not of intellect. Evolution: it's here; get used to it.

[Tip o' the hat to Shakesville]