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ESSAY
PERCEPTIONS OF SCIENCE
Interpreting natural phenomena in human terms is a two-edged sword, generating knowledge as well as opening the door to troubling misunderstandings.
In a recent and well-publicized case, two northern snakeheads (Channa argus*an Asian fish often raised for food in flooded rice paddies-were discovered along with a cohort of fingerling progeny in a suburban Maryland pond. State biologists all but panicked, and the media converged on the pond for a photo opportunity to go with the news story.
Metaphors carried the message: Snakeheads (see the figure, right) are not merely foreign, they are "Frankenfish." Like other immigrants, they were accused of immodest fecundity. State of Maryland biologist Bob Lunsford was quoted: "It's the baddest bunny in the bush. It has no known predators in this environment, can grow to 15 pounds, and it can get up and walk. What more do you need? If you catch it, kill it. It's not a dead or alive thing, we want it dead." (1). An official "unwanted" poster stated: "Kill this fish." Nature picked up the news story (2), and Science alluded to it in a NetWatch item (3). Each of these reports included the press release hyperbole: land-walking, voracious, an ecological disaster.
Metaphors are ubiquitous in science. Most biologists are familiar with archdeacon William Paley's illustration for the existence of an omniscient creator: in the same way a watch found on a beach implies the existence of a watchmaker, the complex design of organisms implies the existence of a designer. The popularity and persistence of this metaphor-with proponents of Intelligent Design as well as with ultra-- Darwinists such as Richard Dawkins-lies in its simplicity and intuitive appeal.
Simplicity and intuitive appeal are also the main reasons why scientific language has never succeeded in "cleansing" itself from metaphorical "impurities," despite several attempts to do so. Indeed, metaphors appear to be essential to all forms of language and understanding (4). But if scientific language is by necessity to some extent metaphorical, then interpretation of its content depends on the cultural context that generates the metaphors that are used. And here the problems start.
Evolutionary biologists customarily employ the metaphor "survival of the fittest," which has a precise meaning in the context of mathematical...