Mobile DNA: Finding Treasure in Junk

1. Introduction to Mobile DNA

Charles Darwin would be surprised. Indeed, even present day scientists are surprised by the existence of mobile DNA. Consider the skepticism within the scientific community that greeted Barbara McClintock, already a highly-respected scientist, when she announced that she had found what appeared to be mobile DNA in maize plants (McClintock, 1950). DNA was the genetic material, so it must be static, stable, and immobile. The mutation rate had been determined to be ~10^-8 per nucleotide, or building block, of DNA per generation—very low indeed. How and why would some DNA move from place to place in a genome? Scientists are still grappling with these questions. Two hundred years removed from Darwin’s birth, and we’re ...