““Genes, oddly, compromise only a minuscule fraction of it. An enormous proportion-a bewildering 98 percent-is not dedicated to genes per se, but to enormous stretches of DNA that are interspersed between genes (intergenic DNA) or within genes (introns). These long stretches encode no RNA, and no protein: they exist in the genome either because they regulate gene expression, or for reasons that we do not yet understand, or because of no reason whatsoever (i.e., they are "junk" DNA). If the genome were a line stretching across the Atlantic Ocean between North America and Europe, genes would be occasional specks of land strewn across long, dark tracts of water. Laid end to end, these specks would be no longer than the largest Galapagos island or a train line across the city of Tokyo,””