Wednesday, November 28, 2007

Evolution and Purpose

 
The first issue of Evolution: Education and Outreach is available online [Contents]. You can read all 21 articles.

Many of them are very interesting but I'm particulary struck by one with the title The Question of Purpose by David Zeigler. The question of purpose in evolution is very contentious. If we stick to science, it's clear that there is no purpose to evolution. What this means is that science is at odds with every religious belief that requires purpose (e.g., God made us).

Many believers resist this interpretation of science by declaring that conclusions about the absence of purpose cross over into the realm of metaphysics. Therefore, science does not rule out a purposeful universe.

David Zeigler is having none of that kind of excuse ...
My “purpose” (we can create our own temporally and spatially limited purposes) in writing this piece is to point out one of the most important and real issues in the teaching of Darwinian evolution that so often goes unaddressed, or more amazingly—unrecognized, and this issue is really fairly obvious. Darwinian evolution by natural selection results in adaptations which increase the ability of the individuals to survive and reproduce successfully in their respective environments, or as biologists would say—adaptations increase the fitness of individuals. This is the only evolutionary goal or purpose for which science has found objective evidence.

In our science, there is no mention of, or mechanism for achieving, any long-term metaphysical or teological goals of form, complexity, or intelligence—as Gould has argued so eloquently. Most of the other known mechanisms of evolutionary change such as genetic drift, neutral mutation, gene duplications, transposons, horizontal gene transfer by plasmids, and others have no direction or goal at all and are in fact random (which natural selection is not) and therefore could not possibly give a particular direction to evolution. Numerous science writers have made the obvious point that had that asteroid not struck some 65,000,000 years ago and pushed the dinosaurs to extinction, we humans would undoubtedly not be here, for the evolution of mammals would have been constrained and altered drastically from what has come to pass (i.e., we humans were not destined to evolve).

If we teach evolution honestly, we cannot really avoid this point, although many succeed in doing so. Additionally, if we give any credence to some hybrid form of teleological evolution by which humans or any of the so-called “higher” forms were destined to appear, we have gutted Darwinian evolution of its scientific core and replaced it with an unfounded belief—one that too many of our students (and most intelligent design proponents) already hold. I believe it is in part because we tiptoe around the honest interpretation of Darwinism that the USA lags far behind the other developed countries of the world in accepting the modern scientific view of evolution and in taking a realistic view of our precarious place (and responsibilities) on this fragile planet.
I don't like his use of "Darwinism" as an incorrect substitute for "biological evolution" but it's otherwise a fine piece. If this is an indication of the quality of article that will appear in the new journal then I'll be looking forward to each issue.


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