Science Literature

Paper from the colloquium: In the light of Evolution

According to Michael Lynch, "the myth that all of evolution can be explained by adaptation continues to be perpetuated by our continued homage to Darwin's treatise in the popular literature. For example, Dawkins' agenda to spread the word on the awesome power of natural selection has been quite successful, but it has come at the expense of reference to any other mechanisms, a view that is in some ways profoundly misleading." Despite all the textbooks and most popular literature giving the impression that adaptive forces are the key to understanding evolutionary transformation, there are very real questions as to "whether natural selection is a necessary or sufficient force to explain the emergence of the genomic and cellular features central to the building of complex organisms."
Lynch describes evolution as "a population-genetic process governed by four fundamental forces." These are: natural selection (which is adaptive), mutation, recombination and genetic drift (which are non-adaptive). "Given the century of work devoted to the study of evolution, it is reasonable to conclude that these four broad classes encompass all of the fundamental forces of evolution."
The body of Lynch's paper is really a manifesto for non-adaptive forces being central to our understanding of organismal complexity, so that the features of interest "may be nothing more than indirect by-products of processes operating at lower levels of organization."
This is probably the most significant paper in the colloquium. It demonstrates the vulnerability of the adaptationist paradigm to critical scrutiny. "If complexity, modularity, evolvability, and/or robustness are entirely products of adaptive processes, then where is the evidence?" Significantly, it is questioning like this that has been ruled inadmissible in the education of biology students in several US states!
But what happens when the non-adaptive 'forces' (with the addition of migration) are critiqued and found to be inadequate for creating complex specified information? What if we come to the conclusion that biological information demands intelligent causation? What is needed is a rational exploration of these issues, not a "religious adherence to the adaptationist paradigm" nor a demarkationist blocking of ID concepts from the domain of science.

The frailty of adaptive hypotheses for the origins of organismal complexity
Michael Lynch
Published online before print May 9, 2007
Proceedings of the National Academy of Sciences USA, May 15, 2007, vol. 104, suppl. 1, 8597-8604 | doi 10.1073/pnas.0702207104

Abstract: The vast majority of biologists engaged in evolutionary studies interpret virtually every aspect of biodiversity in adaptive terms. This narrow view of evolution has become untenable in light of recent observations from genomic sequencing and population-genetic theory. Numerous aspects of genomic architecture, gene structure, and developmental pathways are difficult to explain without invoking the nonadaptive forces of genetic drift and mutation. In addition, emergent biological features such as complexity, modularity, and evolvability, all of which are current targets of considerable speculation, may be nothing more than indirect by-products of processes operating at lower levels of organization. These issues are examined in the context of the view that the origins of many aspects of biological diversity, from gene-structural embellishments to novelties at the phenotypic level, have roots in nonadaptive processes, with the population-genetic environment imposing strong directionality on the paths that are open to evolutionary exploitation.