It is an unfortunate circumstance that ENCODE publicity decided to declare “junk DNA” dead, again. It’s not a totally unique position. Creationists and John Mattick have argued that there is no useless DNA for ages.
The demise of “junk DNA” is a fait accompli of the way “functional” is defined. It is not a definition of “functional” most of us would recognize. Ewan Birney, who should know, explains that when ENCODE says “functional” they mean “not biochemically inert in at least one of our many assays*”. As Mike has noted from his own research experience, many totally random DNA sequences synthesized in a tube are “not biochemically inert” nor are they biologically “functional”.
The fact is, if you only think of “junk DNA” as a problem, you aren’t seeing the forest for the trees – and you certainly are lacking a touch of poetry in your bleak soul. Continue reading “An ode to junk”