Aging and obesity research share an outlook that is misguided. Aging researchers are looking for the clock that times the onset of the aging process. This reminds me of the time that brain researchers were looking for the command neuron in the brain that ran everything. It is an error that comes from what I call the centralized mind set; the coordination of processes that appear to be complex is attributed to a central commander. Nothing real and adaptive, like a human being, works that way (think of it as the Soviet model of the organism). There are many clocks in the human organism: the glucose clock, the unwinding of peptides, the deterioration of the telemeres, the pulses of the calcium gradients over the cell membranes, the tidal rhythms in the lungs, the heart beat. All these clocks are self-organized and lack any central control. They work the way they do because that is the way things are--the chemistry and the dynamics make it happen, no mysterical force or guidance does it. All these clocks that have been tracked exhibit chaotic dynamics; their basins of atraction are not fixed points, or even limit cycles but strange attractors. The clock beat (or return time on the attractor) pulses with the rhythm of natural systems which is described by power laws. Such laws, where intensity is distributed over frequency as 1/f, are the intrinsic dynamics of all natural systems that have been studied in enough detail to make the determination. Our mail list shows the same kind of behavior, bursts of activity and periods of stasis without characteristic scale; we share the statistical distribution of earthquakes and stock market price changes. The signature of chaos and adaptive dynamic systems is a mixing of many time and event scales. This is precisely the situation in the human organism. There is no single clock. What makes us tick is the mixing of millions of clocks, each running on their own attractors and pulsing at power law variations. The search for an aging clock is doomed and misconceived. The real issue is how all these clocks are coordinated. I suspect that cyclic amp, the ubiquitous second messenger hormone is at work, among many other coordinating mechanisms. That is how slime mold organisms become coordinated---a glucose crisis triggers a camp release which coordinates aggregation. From then on, the aging of the organism follows a definite sequence. A similar argument can be made for the fat set point (the idea confuses a basin of attraction with a point, ignores how you move out of a basin, fails to specify how the set point is set, and neglects that a set point is not evolutionarily elegant in design), but I have used up my space. Arthur De Vany Professor <[log in to unmask]> NeXTMAIL, SUN Mail & MIME welcome http://www.socsci.uci.edu/mbs/personnel/devany/devany.html Department of Economics Institute for Mathematical Behavioral Sciences 3151 Social Science Plaza Irvine, CA 92697-5100