Brian Hayes discusses the work of my UCI Computer Science colleague and next-door-neighbor Eric Mjolsness on the biochemical origins of Fibonacci-number spiralling patterns in plants. Turing had suggested that special cells at plant stem tips generate chemical growth factors, and the concentration in the factors there leads to the growth patterns, but Mjolsness' work (with several other authors, recently published in PNAS) shows that instead the growth factors are generated uniformly throughout the growing plant shoot and concentrated in the tips by chemical transport. Eric had just spoken about this at the math meeting in New Orleans, at about the same time as I was there for SODA. The Computer Science part of Mjolsness' research is in developing computer simulation models of biological systems that are large-scale enough and accurate enough to be able to simulate this sort of behavior.
It was also interesting to me to see the explicit statements about who did what part of the paper as footnotes to the PNAS abstract. We have to supply such information on our own papers whenever we go through any sort of personnel evaluation, but for PNAS it is part of the public record.