In late July, several dozen physicists with an interest in biology gathered at the Colorado mountain resort of Snowmass for a birthday celebration. Hans Frauenfelder, a physicist who began studying proteins decades ago, turned 80 this year. But unofficially, the physicists were celebrating something else — a growing feeling that their discipline’s mindset will be crucial to reaping the harvest of biology’s postgenomic era.
Of course, physics and its techniques have played a significant role in biology for decades. X-ray crystallography and nuclear magnetic resonance are essential tools for structural biologists. Biophysicists study everything from the forces exerted by molecular motors to the energetics of enzyme catalysis. And electrophysiologists need a working knowledge of the Nernst equation, which describes the movement of ions across cell membranes.
Many of the founders of molecular biology were also originally physicists. But in the 50 years since people such as Max Delbrück and Francis Crick created the field, it has abandoned its roots. Physics is theory-driven; molecular biology has become an empirical and descriptive science. Physics uses mathematics to represent the laws of nature; molecular biology relies on words and diagrams to describe the functions of living things. The essence of physics is to simplify, whereas molecular biology strives to tease out the smallest details. To cynics, the latter has become an exercise in molecular stamp-collecting, slotting new components and interactions into ever more complex biochemical pathways.
The two cultures might have continued to drift apart, were it not for the revolution in genomics. But thanks to a proliferation of high-throughput techniques, molecular biologists now find themselves wading through more DNA sequences and profiles of gene expression and protein production than they know what to do with. It may be time to take a step back from the details and try to see the big picture.
“Biology today is where physics was at the beginning of the twentieth century,” observes José Onuchic, who is the co-director of the new Center for Theoretical Biological Physics (CTBP) at the University of California, San Diego. “It is faced with a lot of facts that need an explanation.”