Colloquium – William Bialek

William Bialek, Princeton University

physics (and a little chemistry) for maggots

The development of a single cell into a fully functional organism is one of Nature’s most extraordinary phenomena. In a fruit fly, the larva—a maggot—can walk away from the discarded egg shell just 24 hours after the egg is laid. Even more strikingly, if we measure the concentrations of fewer than a dozen crucial molecules we can see a “blueprint” for the segmented body plan of the maggot after just three hours. This process is extraordinarily precise, yet the relevant information is encoded by molecules that are present only at very low concentrations. This contrast can be made more precise: given the small numbers of molecules and the limited time available, it is likely that the observed precision is only barely possible. This motivates a physical principle: the underlying genetic network is tuned to extract as much information as possible from a limited number of molecules. The parameter-free predictions of this theory provide a successful account of detailed, quantitative experiments.

BIO: William Bialek has worked on a wide range of theoretical physics problems motivated by the beautiful phenomena of life, from the dynamics of single protein molecules to ordering in flocks of birds and from computation in the brain to pattern formation in the embryo.  His goal is to find principles with the power and generality that we expect in physics but which nonetheless capture the complexity and particularity of real biological systems.  His work has been recognized by the Max Delbrück Prize in Biological Physics from the American Physical Society and election to the National Academy of Sciences, among other honors.

April 10, 2025 @ 4:10pm Central in Stevenson 4327

Host: J. Velkovska