Something from Nothing Dept.
How do you get optimization by chance? In a Concepts piece in Nature this week,1 William J. Sutherland (U. of East Anglia, UK) suggested that the constraints of the environment will drive living systems toward optimal solutions. He thinks that’s how “selective forces” shaped your teeth and jaw, for instance. Economists and engineers use optimization theory, he reasons, so why not biologists?
The use of optimization has allowed biologists to move from merely describing patterns or mechanisms to being able to predict, from first principles, how organisms should be designed. Optimality models are based on three elements: the choices available; what is being optimized; and the constraints.
Physiologists have used optimization to answer a wide range of questions about animal morphology. For example, optimization has been invoked to predict the design of a bone of given weight that minimizes the risk of breaking or buckling; the speed at which it is most efficient to switch from running to walking; and the gut design that provides the highest energy gain from a given diet. The prediction of the triplet code as the most parsimonious means of coding 20 amino acids using the four bases of DNA is another successful example of this methodology. (Emphasis added in all quotes.)
Though the concept has its critics, Sutherland gives a few more examples of how the optimization approach might have shaped biological systems by natural selection. But intelligent design (ID) is clearly not what he has in mind; he gives Darwin the credit: “Darwin’s theory of natural selection provided an obvious mechanism for explaining optimization in biology: more efficiently designed individuals will leave more offspring.”2 The optimization approach will be fruitful, he concludes:
A considerable strength of using optimization is that once we understand why organisms are as they are, then it should be possible to understand how they will respond to new conditions. Optimization can therefore be used to understand behaviour, and to predict population dynamics, in new environments, such as those resulting from habitat loss or a rise in sea level.
There are increasing calls for biology to be predictive. Optimization is the only approach biology has for making predictions from first principles. The wider adoption of these ideas right across biology should reap ample rewards.
1William J. Sutherland, “The Best Solution,” Nature 435, 569 (2 June 2005) | doi: 10.1038/435569a.
2Of course this is obvious. How do you know the individual is efficiently designed? Because it left more offspring. Why did it leave more offspring? Well, obviously, it must have been more efficiently designed. This circular argument, is an example of a tautology, or a statement of the obvious, like “deaf people can’t hear, because they are deaf.” Natural selection falls into this tautology trap any time fitness is defined in terms of fecundity (see 10/29/2002 entry).
Sorry, Bill. You can’t get the blood of design from a turn-up of natural selection. Necessity is the mother of invention only when intelligence guides the process. The only thing nature is good at optimizing is entropy. The optimization approach will only make sense when design scientists oust the naturalistic usurpers from biology.