The rebuttal to the ENCODE project’s claim to have vanquished junk DNA by Graur et al. got a lot of attention for its scathing rhetoric. If you already have enough troubles in your life, W Ford Doolittle penned a cogent, but polite rebuttal of the claim in PNAS.
…what would we expect for the number of functional elements (as ENCODE defines them) in genomes much larger than our own genome? If the number were to stay more or less constant, it would seem sensible to consider the rest of the DNA of larger genomes to be junk or, at least, assign it a different sort of role (structural rather than informational)…A larger theoretical framework, embracing informational and structural roles for DNA, neutral as well as adaptive causes of complexity, and selection as a multilevel phenomenon, is needed.
Unfortunately, you need a subscription to read the full length article, which I do not. Therefore, I’m not endorsing all of Doolittle’s arguments, but I do like that he seems to agree with my assertion from “Decoding ENCODE” that evolutionary theory expects junk DNA in species with the population and genomic characteristics of humans.
*Hat tip to Leonid Kruglyak.