Murdering to Dissect

by Sally

The years after World War II saw a movement in ecology toward a more quantitatively rigorous science. Ecologists sought to legitimize growing environmental concerns with mathematical equations about population dynamics and species interactions. In 1966, mathematician-biologist Daniel Simberloff and entomologist E.O. Wilson paired up to prove definitively that the number of different species an area of land could support was directly related to its size. They picked a few small mangrove islands off the coast of Florida as their test sites. They first documented the size and number of animal species, all of which were insects, then fumigated the islands, eliminating all animal life. They then monitored the recolonization of the islands by species from nearby islands and the mainland. They found that while species levels always returned to the same size after recolonization, they were not the same in content; that is, the same types of insects did not always repopulate the same islands. These experiments were aimed at providing scientific support for a campaign for larger wildlife preserves. They were meant to show how large, continuous tracts of land were necessary to maintain healthy levels of biodiversity.

Simberloff and Wilson’s experiments were well-intentioned, but their experiments raise some questions about the relationship between science and environmentalism. Science as it is practiced today is highly reductionist, seeking to answer big questions with small experiments. One has to ask whether killing all the bugs on a small mangrove island can really tell us anything helpful about how to not destroy our world. As Donald Worster puts it “how would all the elaborate mathematics help to preserve the earth from degredation?” However, I am inclined to think that despite their penchant for mathematical models, Simberloff and Wilson were not out of touch with the reality of nature. Indeed, they believed that by simulating mass-extinction, they could learn something about the current, real mass extinction that is now happening around us. They simply wanted to test established assumptions about population patterns, something that we certainly need to know more about if we are truly to understand how to protect wild species. A scientist who restricts himself to revering nature and who never tinkers with it is like a surgeon who refuses to dissect a body out of respect for the dead. Yes, they will never do any damage; but neither will they ever learn anything useful.

Watch Simberloff and Wilson talk about their experiment here.
Their segment begins at 34:50.