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Turing Equation Explains how Leopard Spots Develop
BilZ0r writes "A slight modification of an equation developed by Alan Turing in 1952 has been used to show how the patterns of big cats change from kitten to adult markings. Sy-Sang Liaw of National Chung-Hsing University in Taichung, Taiwan, and colleagues set out to replicate these patterns using Turing's equations. But they found they had to do more than just tweak the parameters of the reaction-diffusion equation. Instead they had to assume two stages of spot growth with different rules: the first to get the baby cats their spots, and the second to create the final configurations. It took them a year to find a final solution."
These types of nonlinear differential equations are usually very simple in form, and, most importantly, very local, as that is how most biological interaction is mediated. The parameter tweaking should not be considered too alarming when one considers that the number of biological parameters, in the sense of genetic material, involves thousands of degrees of freedom.
A short (but good) web site about this can be found here. The interpretation of these formulas is fairly trivial, as they describe a diffusion process (common in all biological systems) with a somewhat more complex reactive process, which could be mediated through all kinds of channels.
This is not akin to fitting a polynomial to the shape of a bone and calling that a "model" - there are obvious interpretations which correspond to very well known processes.
anyhow, i believe you ment bread mold, not orange mold.
Penicillium is a genus of what are called 'bread molds' which grow, eponymously, on most yeasted breads. However, they also have a strong affinity for orange rind, and oranges make a nearly ideal culture medium for its growth. Penicillin's antibacteriological properties were discovered in a lab when an orange was accidentally exposed to penicillium and then left in contact with a bacteria culture. Hence, for the story about serendipity and science, its affinity for oranges was more pertinent. Oddly enough, this genus provdes us with some of the molds that make some of the tastiest cheese around (esp. Gorgonzola).
i know the best place to store rubber, place it skin tight on hot girls :D
I, too, like rubber and girls. ;)
All the techniques ever used to make men moral have been themselves thoroughly immoral... (Nietzsche)