One of the more formative experiences of my life was reading Theodor Rosebury’s book Life On Man back when it first came out in 1969. It revealed that our efforts to sanitize the world and rid it of those seemingly pernicious bacteria were not only futile, they were counterproductive.
Our bodies and the surfaces of nearly everything on earth teem with bacteria, most of them friendly, some of them even helping us gain immunity. But sometimes we can get too much information about this phenomenon; it’s not always comforting to think of ourselves as a vehicle for so many hitchhikers of the miniscule variety.
Now comes the news that scientists are mapping the demography of the whole thing. For example, there’s the inside of your elbow, a place most of us don’t think about overmuch:
It is a piece of highly coveted real estate, a special ecosystem, a bountiful home to no fewer than six tribes of bacteria. Even after you have washed the skin clean, there are still one million bacteria in every square centimeter. But panic not. These are not bad bacteria. They are what biologists call commensals, creatures that eat at the same table with people to everyone’s mutual benefit. Though they were not invited to enjoy board and lodging in the skin of your inner elbow, they are giving something of value in return. They are helping to moisturize the skin by processing the raw fats it produces, says Julia A. Segre of the National Human Genome Research Institute.
Just don’t look at the photos. I’ve never been the same after viewing the dust mites (not to mention the thingees that live in our eyebrows) in this book. Consider yourself warned.