"Junk" RNA may have played role in vertebrate evolution

A new study says tiny snippets of RNA co-evolved with vertebrates, likely accounting for the new organisms' complexity.

Genetic material once dismissed as mere "junk" may in fact be responsible to the evolution of simple invertebrates into more complex organisms sporting backbones, according to a new study.

Tiny snippets of the genome known as microRNA were long thought to be genomic refuse because they were transcribed from so-called "junk DNA," sections of the genome that do not carry information for making proteins responsible for various cellular functions. Evidence has been building since 1993, however, that microRNA is anything but genetic bric-a-brac. Quite the contrary, scientists say that it actually plays a crucial role in switching protein-coding genes on or off and regulating the amount of protein those genes produce.

Read full story in Scientific American.