phoric act transcends language and vitalizes creativity in science. . . . [S]cientists . . . conjure like the poet and the shaman[;] . . . their theories are metaphors which ultimately are inseparable from physical reality" ( Jones4-5).
Quammen liberally uses a wide range of figurative tropes, including analogy, paradox, and that favorite of poetry teachers everywhere, synecdoche. Let's look at one salient example: an extended metaphor in which Quammen illustrates the fundamental yet rather slippery evolutionary concepts of the "founder principle" and "genetic drift" by referring to a "drawerful of socks" (219). Quammen-as- teacher invites us to imagine alleles (defined in the glossary as "one of several possible forms of a given gene") as socks, an analogy he calls (with tongue in cheek, I hope) a "pedestrian example" (219). Without summarizing the metaphor here, I'll simply note that Quammen rather cleverly explains (1) how a "population" of socks (constituted by different colors) can change over time depending on which ones get packed for a trip, which colors are more popular in a large group of people, and so on; and (2) how these changes apply to the proportional prevalence of genes in a natural population of organisms. Moreover, Quammen is aware of and deliberately points out the limitations of his metaphor: "There is no precise analogy from the realm of socks, but only because suitcases are incapable of meiosis" (221, emphasis mine). And finally, he adds the coup de grâce: Quammen reminds us, albeit rather subtly, that the expression/concept "genetic drift" (the formal name given to the process by which the gene pool of an isolated population becomes different over time from the gene pool of its larger parent population) is itself a metaphor. Alleles don't literally drift through space and shift position on a chromosome; rather, the frequency with which certain alleles are present in a defined population changes. Drift, as a metaphor, connotes a gradual shift as well as a change in status--a piece of wood that drifts onto a beach changes position but also condition (from wet and heavy to dry and light). Quammen alerts us to the fact that metaphors can turn up in unexpected places in scientific discourse, and thus they require our thoughtful and critical attention.
Through his careful and creative use of metaphor and humor, as well as his effective blending of two functionally distinct narrative personas, David Quammen guides us through the ins and outs of island biogeography while appealing to our imagination, our sense of wonder. Quammen-as-traveler, who partakes of a revised explorer's ethos (one centered upon empathy and understanding rather than objectivity and conquest), complements Quammen-as-educator, who teaches us the lessons of science in the context of a literal and figurative journey. The Song of the Dodo thus exemplifies how the literature of travel and the discourse of popular science co-exist not only comfortably, but also productively. Just as "islands give clarity to evolution" (19), so Quammen's narrative provides a clear view of the development of the long and heterogeneous tradition of science on the road.
I would like to thank Dr. Carol Traynor Williams for her many helpful suggestions in response to an earlier draft of this essay.