“Postgenomic Darwinism” and the Metaphors of Evolution
John Dupré began his lecture, “Postgenomic Darwinism,” by quipping that he had “come to bury Darwin.” In the process, he also revived Lamarck, introduced a competitor to the “tree of life” model, and proposed an alternative view to the old standby that evolution’s primary mechanism is natural selection, with all the connotations of competition and struggle that phrase entails. Dupré’s lecture, in short, suggested an overturning of conventional metaphors and models of evolution in light of recent biological research, a move that will seem appealing to any literature student concerned about the amount of baggage these figures have accumulated in the past century and a half. Darwin’s groundbreaking ideas gave rise to social Darwinism, eugenics programs, a capitalistic ideology of “survival of the fittest,” and psychological Darwinism, a series of associations that empty out and refill the term “Darwinism” with their own ideologically-charged meanings. Little wonder, then, that progressive scientific and humanistic thinkers would have this desire to just throw the term out and begin afresh.
Dupré also called the audience’s attention to the inadequacy of the “tree of life” image for explaining microbial evolution. The mechanism of lateral gene transfer means that for these organisms, inheritance is not the only source of one’s genes; there is also a process of exchange across different branches of the tree, meaning that microbial evolution would be better modeled by a web. Eukaryotic genomes are also affected by lateral processes of gene transfer through viral vectors: 10% of the human genome is composed of potentially functional endogenous retroviruses, and half of our genome consists of fragments or copies of endogenous retrovirus DNA. This suggests that evolution can occur not only in accordance with the old narrative in which a beneficial mutation occurs, and over several generations the new allele becomes widespread while the old one is phased out, a loser in the process of natural selection. Evolution can also potentially occur through fusion of two organisms’ genetic material, in a more cooperative manner. The tree model seems positively teleological compared to Dupré’s web image; the fluidity of boundaries between organisms implied by lateral gene transfer is an exciting possibility for people working to dismantle the fantasy of the integrated, autonomous body; and cooperation among organisms and species is certainly a kinder, gentler model than the violent competition we have come to associate with natural selection.
I think it’s important to keep in mind, though, that while shared metaphors between our fields can certainly foster communication and help us to understand one another in a rudimentary way, we shouldn’t interpret this coincidence of metaphor as proof of some grand truth; nor need we appeal to the authority of scientific discourse to legitimate our own. I’m writing a paper right now dealing with the biological functioning of the influenza virus and its appearance in literature, and at times it’s difficult to remember that the overlaps and identities I find between these two discourses are not necessarily indicative of some universal truth about how the world works, translated into biological and literary narratives. Perhaps this is an example of some of the tensions we saw in The Gold Bug Variations: similarities of pattern between Bach’s variations and the genetic code may be interesting and even productive to explore, but similarities alone do not prove anything. The metaphor is a way of understanding subject to revision, not an answer in itself.
~ by Cari Hovanec on March 27, 2009.