You Are A Topsy-Turvy Lobster

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateOKAY ↓ More info and sources below ↓ Subscribe to It's Okay To Be Smart: http://bit.ly/iotbs_sub Here's why you aren't built like a lobster. Our bodies are mirror images of lobsters and other arthropods from back to belly. We've know since the early 19th century that our guts and nervous systems are inverted from theirs, but only recently has molecular biology shown us why. Here's the evolutionary tale about a worm doing the backstroke and why your guts are on your front. This is part 2 of 3 in my series about how our bodies evolved to look like they do. Check out the others: Part 1 - https://www.youtube.com/watch?v=qdNE4WygyAk Part 3 - Coming Friday! More info: Dorsoventral inversion: http://en.wikipedia.org/wiki/Inversion_(evolutionary_biology) Geoffrey Saint-Hilaire: http://en.wikipedia.org/wiki/%C3%89tienne_Geoffroy_Saint-Hilaire Common animal body plan between protostomes and deuterostomes: http://www.hhmi.ucla.edu/derobertis/EDR_MS/Evo-Devo_page/EVO-DEVO.html How we know that our body plan came later: http://scienceblogs.com/pharyngula/2006/01/12/hemichordate-evodevo/ Step by step along the evolutionary tree: http://tolweb.org/Bilateria/2459 http://en.wikipedia.org/wiki/Bilateria http://en.wikipedia.org/wiki/Deuterostome http://en.wikipedia.org/wiki/Protostome http://en.wikipedia.org/wiki/Urochordata http://en.wikipedia.org/wiki/Chordate http://en.wikipedia.org/wiki/Cephalochordata http://en.wikipedia.org/wiki/Craniate http://en.wikipedia.org/wiki/Gnathostomata Evolutionary timeline of vertebrates: http://www.utexas.edu/news/2008/03/03/tree/ Joe Hanson - Host and writer Joe Nicolosi - Director Amanda Fox - Producer, Spotzen IncKate Eads - Associate Producer Katie Graham - Director of Photography Andrew Matthews - Editor and motion graphics John Knudsen - Gaffer Music: "Ouroboros" by Kevin MacLeod Stock images via Shutterstock Produced by PBS Digital Studios: http://www.youtube.com/user/pbsdigitalstudios ----------- Join us on Patreon! https://patreon.com/itsokaytobesmart Twitter http://www.twitter.com/DrJoeHanson http://www.twitter.com/okaytobesmart Instagram http://www.instagram.com/DrJoeHanson http://www.instagram.com/okaytobesmart Merch https://store.dftba.com/collections/its-okay-to-be-smart Facebook https://www.facebook.com/itsokaytobesmartpbs/​ Learn more about your ad choices. Visit megaphone.fm/adchoices