"Junk" RNA May Have Played Role in Vertebrate Evolution: Scientific American

"Junk" RNA May Have Played Role in Vertebrate Evolution: Scientific American: "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."

Another article highlighting the potential importance of microRNA in evolution and organism definition.