3:30–4:30 pm Maria Geoppert-Mayer Lecture Hall
Geometry and Genetics
Eric Siggia, Rockefeller University
The application of quantitative methods to biological problems faces the choice of how much detail to include and the generality of the conclusions. The middle ground entails some use phenomenology, a well-regarded approach in physics. Genetic screens have uncovered most of the genes responsible for development from egg to adult. But overlaid is the phenomenon of canalization in developmental that is a license to develop models that are quantitative and dynamic yet do not begin from an enumeration of the relevant genes. Modern mathematics, ‘dynamical systems’ so called, has many similarities to experimental embryology and allows the enumeration of categories of dynamical behaviors by geometric methods. Examples from stem cell differentiation, and the embryos of model organisms will illustrate how systems with a few variables can be fit to cell state transitions. Phenomenology of the sort envisioned is essential to bridge the scales from the cell, to tissue to embryo, by breaking the system into blocks that can be separately parameterized.