But back then, they could do little more than wonder. Talks revisited ideas of DNA's multiple roles, and explored how natural selection has shaped the ability of genomes to change, increasing variation. Now that the Human Genome Project shows that probably less than 5 percent of our 3 billion DNA base pairs encode protein, Caporale's landmark paper is even more compelling. And the topics visited at the meeting fit in with functional genomics, the emerging field that is demonstrating that a genome is more than the sum of its parts. The enzymes that copy, move, and repair DNA are the key players in these shufflings.
Genomes evolve a balance between fidelity of replication, and exploration of new opportunities.
In the classic Darwinian sense, natural selection occurs because organisms with inherited traits that are beneficial in a particular environment preferentially survive long enough to reproduce, thereby gradually altering the genetic composition of a population. The talks emphasized that the very ability to generate variation is a selectable trait. And viewed under this evolutionary umbrella, genetic discoveries that seemed out of place as the details of gene function were worked out in the 1960s and 1970s now make sense. Speakers liberally evoked geographical metaphors, describing genomes as landscapes, terrain, scenery, and dynamic playgrounds. But the speakers and posters used the term to denote mechanisms that enhance the probability of survival to reproduce, the crux of natural selection.