Science Literature

We are indebted to Gould and Lewontin for pointing out so eloquently to adaptationists that biological structures should be explained in context and not as independently constructed adaptations. They wanted to revive the great historic themes of developmental morphology and the bauplan in which some features are, like spandrels, consequences of a larger-scale architecture. David Hartl has chosen to remind readers of this emphasis in his review of a book on the origins of genome architecture.
At the outset, some garbage must be cleared away. Adaptationists have tended to develop lazy ways of thinking and rarely seek out ways to test their offered scenarios. "Glib generalizations [according to the author] come from the assumption shared by many biologists that natural selection is the only mechanism of evolutionary change, and hence every observed feature of organisms must have come about because of natural selection." This mechanism is highly prized because they think it can do anything. They claim it is the great creator of complexity. But the concept is qualitative, not quantitative, and there are inadequate checks to avoid the pathways to fantasy. "This conveniently licenses anyone to concoct any adaptive story about anything biological and put it forward as a serious contribution to the science of evolution."
Michael Lynch, the book's author, has come to the view that many complex structures cannot be explained using adaptation. "The recurring theme is that many of the major molecular features of genes and genomes in multicellular organisms can be explained without invoking natural selection. The list will raise some eyebrows: it includes the transition from the RNA world to DNA, streamlining of microbial genomes, variation in nucleotide composition within and among genomes, centromere expansion, proliferation of transposable elements, growth of untranslated regions in messenger RNAs, origin of spliceosomes and the proliferation of introns, origin of modular gene regulation, variation in the architecture of organelle genomes, mRNA editing in plant organelles and the evolution of sex chromosomes."
"The problem with natural selection is that if it explains everything, it explains nothing, and instead it becomes an exercise in story telling. [. . .] The challenge for those who would invoke natural selection as causing any biological feature is therefore to propose a specific adaptive mechanism, to deduce attributes that would differ according to which hypothesis were correct and then to make the necessary observations or comparisons."
What a welcome airing of these issues! And wouldn't it be good if biology students could be alerted to such thinking before they get brainwashed by neo-Darwinism?

The spandrels of the genome
Daniel Hartl
Nature Genetics, 39, 811 (July 2007) | doi:10.1038/ng0707-811

BOOK REVIEWED - The Origins of Genome Architecture by Michael Lynch, Sinauer Associates: 2007

See also:
Gould, S.J. & Lewontin, R.C. The spandrels of San Marco and the Panglossian paradigm, Proceedings of the Royal Society of London, B. 1979, 205, 581-598.