New Theories of Evolution?
Darwin was not the first to suggest that species evolved. The theories put forward by those such as Lamarck, Buffon, and Erasamus Darwin although interesting and thought provoking never succeeded in entering the public imagination, and remained a part of specialized intellectual discourses and to a fringe element. I think that what accounts, at least in part, for the success of Darwin’s theory is that it offers a straightforward and logical mechanism that is easily followed by the average member of society. Darwin’s theory offers a clear explanation that requires no specialized knowledge and does not require a leap of faith on the part of the reader. One might say of Darwin’s theory what Winston Churchill said of Democracy, that it may be the worst explanation of evolution, except for all the others that have been tried; as imperfect as it is, it is still the only game in town, or is it?
In a recent article entitled “Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land” authors S. Sahney et. al., engage in a statistical analyses of “tetrapods” in the fossil record in an attempt to explain their “exponential increase from one species to many tens of thousands .” In their explanation for the explosion of tetrapod species the authors offer an alternative to competition as the driving force behind evolution citing instead “the expansion of habitats occupied as tetrapods moved from the waterside to exploit new sectors of the earth’s surface, such as forests, plains and deserts.” Although the authors of the paper do admit that competition in the form of “incumbent replacement” does take place, this would mainly occur after “major environmental disruption such as a mass extinction” and the authors conclude that “tetrapod diversity was primarily achieved by unrestricted expansion into empty eco space.” It was not through unrelieved competition that was responsible for bio diversity (evolution), but rather that organisms adapted to make use of previously unexploited sources of food, allowing them the run of the niche as it were.
Advances in science and technology and a more complete picture of the fossil record have resulted in new theories that claim to explain evolution such as that discussed above. However, these new and viable theories seem to have little impact on the primacy of place given Darwin’s never ending struggle for existence. Perhaps one of the factors that explains the continuing success of Darwin’s theory is not so much that his argument is airtight – as a theory it still leaves many questions unanswered, but rather its rhetorical or narrative force. Put simply, Darwin’s theory is a much more dramatic, even romantic view of evolution that dovetails nicely with the way many would see themselves: the noble individual struggling against all odds to establish a family and live a peaceful and fruitful life; compared to the statistical analyses of taxa and minute inspections of the fossil record Darwin wins hands down. My guess is that Darwin’s theory will remain the leading one in the mind of the average rational individual until one more exciting comes along.