June 10, 2005

Life in All Its Rich Variety — Do Not Falter!

There are days I am glad I'm a mathematical scientist.

Paul B. Eckburg, Elisabeth M. Bik, Charles N. Bernstein, Elizabeth Purdom, Les Dethlefsen, Michael Sargent, Steven R. Gill, Karen E. Nelson, and David A. Relman, "Diversity of the Human Intestinal Microbial Flora", Science 308 (2005): 1635--1638
Abstract: The human endogenous intestinal microflora is an essential "organ" in providing nourishment, regulating epithelial development, and instructing innate immunity; yet, surprisingly, basic features remain poorly described. We examined 13,355 prokaryotic ribosomal RNA gene sequences from multiple colonic mucosal sites and feces of healthy subjects to improve our understanding of gut microbial diversity. A majority of the bacterial sequences corresponded to uncultivated species and novel microorganisms. We discovered significant intersubject variability and differences between stool and mucosa community composition. Characterization of this immensely diverse ecosystem is the first step in elucidating its role in health and disease.

One reason papers like this gladden my heart is my basic intellectual cowardice: the sheer endless proliferating detail of biology overwhelms me, especially when something drives home the fact that we keep finding utterly new stuff everywhere we look. Here we are, looking at our own guts, and coming up with stuff like this: "Three sequences from two subjects ... appear to represent a novel lineage, deeply branching from the Cyanobacteria phylum and chloroplast sequences." See? There are organisms whose closest relatives are the stuff that turns ponds and leaves green living inside us, and until now we had no idea. And when we eventually look inside them, they're going to turn out to be weirdly complicated and uniquely strange, exactly like everything else. And of course the damn things will have histories, again exactly like everything else. Biology just doesn't stop, and at some point the details and special cases make me wish my head would explode.

Fundamentally, however, stuff like this cheers me up because my work does not involve collecting colonic mucosa.

Update, that afternoon: Oh, dear, I knew that last joke was going to turn out to be a mistake. Really, I was aiming for a tone of sour grapes adaptive preferences: I think this kind of science is utterly fascinating, and I wish I could do it, but I just don't have the ability to keep masses of detail straight in my mind which I'd need to do so. This rather amuses the half of my immediate family consisting of experimental biologists. So, pace my good friend Bill Tozier, I really would like you to know what's up your butt; or at least like someone to know. Bill's post raises many fine issues, and deserves a full response, but for now he'll just have to be content with my muttering something about quasiparticles.

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The Natural Science of the Human Species; Biology

Posted at June 10, 2005 08:47 | permanent link

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