Second, the 34,000 genes take up only about 3 percent of the human genome. The rest consists of DNA that does not code for protein and that used to be dismissed as “junk.” But as one biologist recently put it, “The term ‘junk DNA’ is a reflection of our ignorance.” 11 The size, placement, and content of the noncoding DNA can have dramatic effects on the way that nearby genes are activated to make proteins. Information in the billions of bases in the noncoding regions of the genome is part of the specification of a human being, above and beyond the information contained in the 34,000 genes.
