Chaos theory

One of the best programmes on the BBC is Melvyn Braggs In our Time. Full of knowledge and wisdom. There is also a wonderful newsletter that comes from his broadcast.
This programe on 29th May talks of chaos theory, of great relevance to biology.
Marcus du Sautoy pointed out that probability comes into play when picking numbers for the National Lottery. The sequence of numbers: ‘1, 2, 3, 4, 5, 6’ are just as likely to come up as any other combination of numbers. Numbers are more likely to come up in clusters because randomness likes to cluster things together (so often you will see clusters of things in a random sample); so if you pick say 42 followed by 43 (e.g. consecutive numbers), there may be slightly more chance of winning a prize
Physical systems that are deterministic yet impossible to predict (ie: requiring
probabilistic predictions) is the study of chaotic systems or ‘Chaos Theory’. Chaotic systems were not totally random, crazy and unpredictable but actually rather simpler than they might appear. They follow meta rules, structures and patterns that you can observe, extract and use. So in that sense it is deterministic (ie: run it twice under same conditions and the same outcomes will happen) as opposed to random (which by definition means running the same thing under the same conditions
and getting different outcomes).
However, chaotic systems are characterised by something popularly called the butterfly effect – that if a butterfly beats its wings in Rio you get hurricanes in Tokyo.This is better referred to as ‘extreme sensitivity to initial conditions’. A small effect early on leads to vast differences later on. To accurately predict the future of a chaotic system, a measurement of what it is doing now (and upon which the prediction is based) must be unbelievably accurate – just as a butterfly’s wings can create storms, so a small error in initial measurement can lead to vast errors in predicted outcomes.
And what does this have to do with nutrition. Metabolism is in part chaos theory in action. The food supply chain certainly is. Choice of food and marketing.

Martin Eastwood
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