Ayala and Falk Miss the Signs in the Genome

In his recent response to Stephen Meyer’s Signature in the Cell, Francisco Ayala claimed that repetitive portions of our DNA called “Alu” sequences are “nonsensical.” Ayala wrote: “Would a function ever be found for these one million nearly identical Alu sequences? It seems most unlikely.” In his response to Ayala, Meyer showed that Ayala is factually wrong about this. According to recent technical papers in genomics, Alu sequences perform multiple functions. In a rejoinder to Meyer, Darrel Falk defended Ayala and claimed although “a number of functional regions have been discovered within Alu sequences,” there “is no question that many Alu sequences really have no function.” In my last blog, I showed that the vast majority of the genome is Read More ›

Asking Darrel Falk to Pick a Number, Any Number

I have long questioned the assumption that most genomic DNA sequences are “nonsensical” or “junk.” And given the data that have emerged over the past seven or so years, a functionalist view of genome has robust empirical support. It is for this reason that I think many of the arguments presented by the Biologos Foundation are “wrong on many counts,” to borrow a phrase from Darrel Falk. Here is an example. While reading the “critique” of Steve Meyer’s book, Signature in the Cell, by Francisco Ayala, a number struck me that I know to be incorrect. The integer that I am referring to is “25,000” and it is claimed to be the known tally of genes in our chromosomes: The Read More ›

How The Junk DNA Hypothesis Has Changed Since 1980

As someone who has studied the concept of “junk DNA” for over twenty years, I am dismayed by two statements that appear repeatedly on various blog sites discussing evolution. No, I am not referring to arguments of the form “the onion has six times more DNA than do mammals; therefore, there is no deity,” that are invariably followed by terms of disparagement hurled at anyone who even marginally departs from the Darwinian perspective. Rather, my consternation stems from a half-truth and a false fact that are recycled ad nauseum by those who apparently believe that, despite all the genomic and transcriptomic data that have been obtained only in this decade — data that have overturned a number of trenchant assumptions–a Read More ›