Eraxion, istockphoto.com

In a New York Times article about evolutionary optimization in biological systems, SFI Science Board member and External Professor Charles Stevens cites the uncanny ability of our brains to react accurately and rapidly to a stimulus by considering an overabundance of neural signals and averaging out neural noise.

The notion of optimization -- that some elements of biological systems have been honed by evolution to the best, most efficient levels of performance possible -- is gaining wider acceptance among scientists, the article notes. Examples include photoreceptor cells that detect and respond to a single photon of light, sharks as they find prey by detecting impossibly small electrical fluxes in the water, and our fight-or-flee brain responses.

In each case, biophysicists say, the system couldn’t get faster, more sensitive, or more efficient given their physical constants.

Often, the system’s approach to achieving these performance levels seems counterintuitive. As a ballplayer’s muscular and neural systems work together to throw a pitch, for example, they tolerate a high degree of variability. The pitcher’s movements are somewhat different every time, but a precisely and rapidly hurled ball is almost always the outcome. The sameness is enough to achieve the desired result the majority of the time, but the system’s tolerances are not so strict as to prompt inefficiencies.

By identifying general principles of optimization and encapsulating them in an elegant set of equations, scientists might one day be able to predict and test how other living systems behave optimally -- and perhaps even suggest what optimal non-living systems might look like.

Read the New York Times article