It is worth remembering, when deadly pathogens are in the news that most microscopic species are either of no consequence to human health and well-being or are beneficial. Also, they are unstudied. Take the case of Manhattan. Manhattan is a borough of a somewhat large city reported to be full of culture, intellectualism, and black clothes. Probably, these things are true. In my lab, we mostly go there to study insects and, more recently, bacteria. In considering the bacteria of Manhattan, we have sampled medians from Broadway to Riverside, dozens of medians, those patches of green between lanes of traffic, patches filled with ants and rats and, as it turns out, bacteria. We are looking at our data now, trying to understand what bacteria live where in Manhattan and why. One thing pops out: among the tens of thousands of kinds of bacteria we have found, some are more common than others. The seven most common kinds of bacteria are three species of the genus DA101, one species of Rhodoplanes, one of Bradyrhizobium, one of Ellin6075, and one of iii1-15.
If you are from New York, or at least if you are from the cartoon-like depiction of New York I’m entertaining here that you might respond to this list with something along the lines of, “What the F*$#K, those aren’t even words,” though maybe such a response would be more Brooklyn than Manhattan.
Actually, two of them are words, pronounceable names. The genera Rhodoplanes and Bradyrhizobium are real, named life forms (genera). We know relatively little about Rhodoplanes. Bradyrhizobium is better studied; it associates with plant roots where it has the magical talent of being able to grab nitrogen out of the air, change it into easier to use forms and then hog-trade those forms with plants for sugars.
But this story is not about Bradyrhizobium, it is about DA101, Ellin6075 and iii 1-15. These clearly aren’t words. They seem like email passwords or the sorts of unsayable combinations of letters and numbers that celebrities now use to name their children. Actually, what they are is even odder; they are codes given to these kinds of bacteria as temporary placeholders until someone figures out how to grow and study them. You see, we did not actually see these bacteria. Instead we detected them on the basis of the presence of their DNA in the soil; their DNA has a specific sequence, a sequence that tells us who these bacteria are, enough to document their existence but not enough to tell us more about them, such as what they do, and not enough, given the scientific rules for naming creatures, to give them a permanent name.
For six of the ten most common bacteria in the soils of medians, including three species of the provisional genus DA101, a species of the provisional genus Ellin6075 and a species of the genus iii 1-15, all we can say is to which other species of bacteria they are related. Well, that and also that they are probably the most abundant organisms in Manhattan, the real owners of the habitat in which humanity is squatting. A species of DA101 is the very most abundant, if you were wondering, the real king of Broadway and perhaps each other place we put our feet.
But while DA101 may well be the most common species in Manhattan, it is just one of tens of thousands of unstudied species, the tangible and yet invisible richness of our ignorance, a richness you brush against every day, a richness you can pick up in a pinch of dirt from anywhere in New York, a pinch in which, our data show, more than a thousand species are likely to be found, species that go on living even as you lift them toward your face, species unaware of our human delusions of grandeur and understanding, unaware of much of anything except for the other microbes around them, and the presence or absence of their preferred sustenance, whatever we someday discover it to be.