What is Junk DNA, and Why Do We Have So Much?

Have you ever wondered about junk DNA? Each person’s human genome is 3.2 billion base pairs long and contains around 20,000 genes, but how much of that is garbage? Find out all you need to know about Junk DNA in this new episode of SciShow, hosted by Hank Green! Head to for hand selected artifacts of the universe! ---------- Support SciShow by becoming a patron on Patreon: ---------- Dooblydoo thanks go to the following Patreon supporters: Lazarus G, Sam Lutfi, D.A. Noe, سلطان الخليفي, Piya Shedden, KatieMarie Magnone, Scott Satovsky Jr, Charles Southerland, Patrick D. Ashmore, Tim Curwick, charles george, Kevin Bealer, Chris Peters ---------- Looking for SciShow elsewhere on the internet? Facebook: Twitter: Tumblr: Instagram: ---------- Sources: (14)00523-1?_returnURL=