Debunking DNA "Junk" Ideas
Adenine, thymine, guanine, cytosine. Biology teachers repeated those molecules to us in high school. We had to memorize themalthough they were already embedded in our brains, literally speaking. Working in tandem, those four bases compose a four-letter code giving instructions to every living cell, ultimately sketching a blueprint for life.
The code, DNA, is microscopically wound in the elegant double helix that James Watson and Francis Crick discovered in 1953. It seemed charmingly simple: Two ribbons of chemical code, weakly attracted to one another, could be unzipped and copied (allowing a cell to divide), or transcribed to RNA, which used the instructions to make proteins. These proteins, like miniature laborers, then flew off to whatever cellular task the DNA had in mind.