Post Author: Bill Pratt
I just finished reading James Shapiro’s book, Evolution: A View from the 21st Century. Shapiro is Professor of Microbiology at the University of Chicago and a deeply influential figure in evolutionary biology.
He is not a fellow at the Discovery Institute, but, shockingly, he finds the currently popular evolutionary mechanisms of natural selection and random mutation to be woefully inadequate to explain how biological evolution occurs. Shapiro’s book is difficult reading, as he has written it, it seems to me, primarily for professional biologists. There are, however, several places in the book where he brings things back down to earth for the layperson. I’d like to share a couple of his thoughts.
Contrary to the popular view that changes in the genome occur randomly in single nucleotides, Shapiro claims that “genomic innovations occur at many different levels of complexity.” We know this because “we can observe genome reorganization in real time and relate what cells do now to what the DNA record tells us has happened over the course of evolution.”
So what is it microbiologists have found?
Genomic innovations occur at many different levels of complexity. These levels cover the entire range of DNA modifications: from single nucleotide substitutions, to short strings of nucleotides comprising regulatory signals, to longer polynucleotide strings encoding functional regions (“domains”) of protein molecules, through larger DNA segments encoding entire RNA or protein molecules, and finally extending to complexes of multiple coding segments and their attendant control regions.
In a surprisingly large number of cases, genome analysis tells us that reorganization events have comprised whole genomes. Because genome evolution is multilevel, amplifying, and combinatorial in nature, the end results are complex hierarchical structures with characteristic system architectures.
Genomes are sophisticated data storage organelles integrated into the cellular and multicellular life cycles of each distinct organism. Thinking about genomes from an informatic perspective, it is apparent that systems engineering is a better metaphor for the evolutionary process than the conventional view of evolution as a selection-biased random walk through the limitless space of possible DNA configurations. (emphasis added)
If you didn’t follow all of that, here is the bottom line. Genetic changes in organisms are far more complex, multilevel, and systems oriented than previously thought. So what does this say about the standard Darwinian view of evolution as the gradual accumulation of random point changes in the genome over long periods of time? Shapiro explains that
the advent of molecular genetics and genome sequencing was a major step forward in evolutionary science. Examining the DNA record made it possible to subject traditional evolution theories to rigorous empirical testing. Do the sequences of contemporary genomes fit the predictions of change by “numerous, successive, slight variations,” as Darwin stated, or do they contain evidence of other, more abrupt processes, as numerous other thinkers had asserted?
The data are overwhelmingly in favor of the saltationist school that postulated major genomic changes at key moments in evolution. Only by restricting their analyses to certain classes of genomic DNA, such as homologous protein coding sequences, can conventional evolutionists apply their gradualist models. Moreover, we will see from genome sequencing that protein evolution itself often proceeds in relatively large steps. Contrary to the views of Linnaeus and Darwin, nature does indeed make leaps, and we now have molecular evidence of how some leaps occurred. (emphasis added)
One of the central dogmas of evolution, that change occurs by “numerous, successive, slight variations,” is wrong, according to Shapiro. Intelligent design proponents have been making this same argument for decades, but it seems that they now have company. I have no idea where this will all end up, but the ne0-Darwinian edifice continues to crack.