QUOTE: ...Standard evolutionary theory offered no clues. Applying the concepts of control theory, a body of knowledge that deals with the behavior of dynamical systems, the researchers concluded that this self-correcting behavior could only be possible if, during the early stages of evolution, the proteins had developed a self-regulating mechanism, analogous to a car's cruise control or a home's thermostat, allowing them to fine-tune and control their subsequent evolution. The scientists are working on formulating a new general theory based on this finding they are calling "evolutionary control."
The work is likely to provoke a considerable amount of thinking, according to Charles Smith, a historian of science at Western Kentucky University. "Systems thinking in evolutionary studies perhaps began with Alfred Wallace's likening of the action of natural selection to the governor on a steam engine --- that is, as a mechanism for removing the unfit and thereby keeping populations 'up to snuff' as environmental actors," Smith said. "Wallace never really came to grips with the positive feedback part of the cycle, however, and it is instructive that through optimal control theory Chakrabarti et al. can now suggest a coupling of causalities at the molecular level that extends Wallace's systems-oriented approach to this arena."
Evolution, the central theory of modern biology, is regarded as a gradual change in the genetic makeup of a population over time. It is a continuing process of change, forced by what Wallace and Darwin, his more famous colleague, called "natural selection." In this process, species evolve because of random mutations and selection by environmental stresses. Unlike Darwin, Wallace conjectured that species themselves may develop the capacity to respond optimally to evolutionary stresses. Until this work, evidence for the conjecture was lacking... UNQUOTE.
Source: http://www.sciencedaily.com/releases/2008/11/081111183039.htm |
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