Learning to Love Bacteria

 
We live now in the "Age of Bacteria." Our planet has always been in the "Age of Bacteria," ever since the first fossils—bacteria, of course—were entombed in rocks more than 3 billion years ago.

On any possible, reasonable or fair criterion, bacteria are—and always have been—the dominant forms of life on Earth.
Stephen J. Gould (1996)Bacteria don't get much respect in spite of the fact that many scientists have written about their importance [see Planet of the Bacteria by Stephen Jay Gould (1996)]. Over at Deep Sea News they're trying, once again, to rectify this unfortunate situation. This will be an entire week devoted to microbes [Intro to Microbial Week by Christina Kellogg].

Here are some important facts from the first posting to keep in mind whenever you're inclined to dismiss bacteria.

"The number of prokaryotes [i.e., bacteria + archaea] and the total amount of their cellular carbon on earth are estimated to be 4-6 ×: 10³⁰ cells and 350-550 Pg of C (1 Pg = 10¹⁵ g), respectively. Thus the total amount of prokaryotic carbon is 60-100% of the estimated total carbon in plants, and inclusion of prokaryotic carbon in global models will almost double estimates of the amount of carbon stored in living organisms." (Whitman et al. 1998)

and

Numerically dominant--there are approximately 1 million bacteria and 10 million viruses in a milliliter of seawater. There are approximately 0.00000000000000000002 sperm whales per milliliter of seawater.

The point about learning to love bacteria is that it's crucial to a full understanding of our place in the world of living things. This is going to come up discussions about complexity. We need to understand that our perspective is heavily biased. As Gould (1996) writes,

Our failure to grasp this most evident of biological facts arises in part from the blindness of our arrogance but also, in large measure, as an effect of scale. We are so accustomed to viewing phenomena of our scale—sizes measured in feet and ages in decades—as typical of nature.

Individual bacteria lie beneath our vision and may live no longer than the time I take to eat lunch or my grandfather spent with his evening cigar. But then, who knows? To a bacterium, human bodies might appear as widely dispersed, effectively eternal (or at least geological), massive mountains, fit for all forms of exploitation and fraught with little danger unless a bolus of imported penicillin strikes at some of the nasty brethren.

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[Hat Tip: Christopher Taylor at Catalogue of Organisms]

Gould, S.J. (1996) Planet of the Bacteria. Washington Post Horizon 119:(344). An essay adapted from Full House New York: Harmony Books, 1996, pp. 175-192.