April marks the 50th anniversary of the discovery by James Watson and Francis Crick of the double helix structure of DNA — setting the stage for an explosion in our understanding of the building blocks of life. To mark that occasion we’ve asked a variety of UC Davis scholars what they think the biggest impact of that discovery has been on their fields.
Leslie A. Lyons, assistant professor of population health and reproduction in the School of Veterinary Medicine: The discovery of DNA has shown humans that we are actually very similar to other mammalian species. The basic DNA blueprint is mildly altered and rearranged between species. Thus, all the genetic information gleaned from any one species, whether a cat, a mouse or a fruit fly, can be transferred to another species to help understand the basic biology of the organism.
David Robertson, professor of English: It helped jumpstart postmodernism by giving literary scholars plausible biological evidence that human beings don’t just speak and write text. They are made of, for and by text.
Craig Benham, interim director of the Genome Center and Bioinformatics Program: The most significant aspect of Watson and Crick’s proposed DNA structure was not the double helix itself, but the complementary base pairing between the two strands of the molecule. This arrangement encodes the genetic information and thereby provides the chemical explanation for the rules of inheritance of traits. This has led to a revolution in biology, leading up to the elucidation of the complete genetic endowments of organisms.
Ford Denison, professor of agronomy and range science, and director of the 100-year Long Term Research on Agricultural Systems project: It helps us understand how crops and pests evolve.
Edward Imwinkelried, professor of law and expert on DNA evidence: One of the most important long-term effects of the advent of DNA evidence will be its impact on the judicial treatment of other types of evidence. From the outset, it was clear to the courts that DNA typing had the potential to generate extraordinarily important testimony. For that reason, the courts invested the time and effort needed to understand DNA evidence. They rolled up their sleeves and learned a good deal about both the methods of scientific validation and the statistical techniques for evaluating the significance of a “match.” That learning is now influencing the courts’ attitude toward other types of expert testimony, for example, claims by experts in questioned document examination, fingerprint comparison, firearms identification and bite-mark analysis. Moreover, the courts are policing the use of statistical testimony in a more informed manner. In short, the development of DNA evidence forced the courts to learn lessons that they are now putting to use in their assessment of a wide variety of species of non-DNA evidence.
Doug Kahn, director of Technocultural Studies: An impact on cultural theory of DNA has been to rethink the places where meaning is manipulated and how it is developed, detected and understood. Compare the two versions of “The Fly.” In the older movie the fly/human and human/fly appeared to be put together like a photomontage: cut at the surface. In the newer version the cut happened unseen at the genetic level; the transformation was revealed gradually through a complex series of signs.
Pam Ronald, associate professor of plant pathology and expert in rice genetics: Rice is one of only six (including C. elegans, Drosophila, human, mouse and Arabidopsis) higher eukaryotic genomes that have been entirely sequenced. The convergence of genomic sequence, informatics and protein-protein interaction technologies has created the opportunity to dramatically enhance our understanding of cell-signaling in the cereals, using rice as a model system. Development and application of these technologies will augment traditional approaches to create new higher-yielding varieties of cereal species.partment of Justice,” Howitt said, “we have been able to bring a wealth of expertise to the program.”