Last year, the massive ENCODE consortium disclosed that over 80% of the human genome appears to be functional through several detailed biochemical experiments. Their findings fuelled an already heated debate regarding the biological pertinence of similar findings. Many old-school biochemists and proponents of the “selfish” DNA hypothesis (who I collectively refer to as junk DNAy-sayers) dismiss the use of such data to support the notion that the majority of the genome is functional.
Amidst the nit-picking, bickering, and refutations, one logical argument stands out that somewhat confounds the ENCODE findings: the lack of detectable evolutionary conservation. Indeed, the statement that > 80% of the human genome sequence is biologically functional lies in stark contrast to the fact that < 9% of it is observed to be conserved throughout mammalian evolution. But is this estimate really accurate? Continue reading