zondag 20 mei 2007

Evolution By Any Other Name

We've had the opportunity to amuse ourselves at Dr. Egnor's antics in recent months (or, alternatively, hide our head in shame), who insists that there's no reason to study evolution in order to practice medicine. Fortunately, the winners of an essay contest on "Why would I want my doctor to have studied evolution?" were recently announced (hat tip: Orac), thus proving that high school students, at least some of them, have more sense than Dr. Egnor, and all is not lost yet.

Given recent events, this essay which was published in PLoS Biology in February (yes, I'm a little behind the times) seems relevant. Antonovics et al. discuss the peculiar phenomenon that the E-word is often avoided in papers describing the evolution of antimicrobial resistence, in favour of words like "emerge", "arise", or "spread". They compared 15 articles on the subject published in evolutionary journals (e.g. Evolution and Proceedings of the Royal Society of London Series B) with 15 articles published in medical journals like The Lancet.

Although one might quibble with their methods, the differences found are huge:

In research reports in journals with primarily evolutionary or genetic content, the word “evolution” was used 65.8% of the time to describe evolutionary processes (range 10%–94%, mode 50%–60%, from a total of 632 phrases referring to evolution). However, in research reports in the biomedical literature, the word “evolution” was used only 2.7% of the time (range 0%–75%, mode 0%–10%, from a total of 292 phrases referring to evolution), a highly significant difference (chi-square, p < 0.001). Indeed, whereas all the articles in the evolutionary genetics journals used the word “evolution,” ten out of 15 of the articles in the biomedical literature failed to do so completely. Instead, 60.0% of the time antimicrobial resistance was described as “emerging,” “spreading,” or “increasing” (range 0%–86%, mode 30%–40%); in contrast, these words were used only 7.5% of the time in the evolutionary literature (range 0%–25%, mode 0%–10%).

The authors note that "evolution" as a term may be avoided, not for fear of controversy (although that may very well be the case, too), but out of habit or out of a feeling that the word is too imprecise, which is the charitable explanation. Alternatively, the medical researchers may see evolution as a slow, imperceptible process that occurred in the past, which would be worrying. Whatever the likes of Dr. Egnor may think, evolution is still happening today and it is relevant to everyone in the life sciences.

Most interestingly, Antonovics et al. also examined whether the usage of "evolution" in the scientific literature influences the usage in the popular press. As the authors conclude:

Our results showed that the proportion of times the word “evolution” was used in a popular article was highly correlated with how often it was used in the original scientific paper to which the popular article referred. This clearly shows that the public is more likely to be exposed to the idea of evolution and its real-world consequences if the word “evolution” is also being used in the technical literature.

It won't convince all of the creationists, but more coverage of real-life examples of evolution, called by its proper name, may help sway a few doubters our way. Let's call a spade a spade.