Thanks to Unbounce for sponsoring today's video. Go to https://thld.co/unbounce_scishow and use the promo code SCISHOW at checkout to get 20% off your first 3 months. Experiments conducted by Hilde Mangold and Hans Spemann taught us how an animal develops from a small ball of cells into an organism with distinct, functioning parts. The work was a foundational contribution to the field of developmental biology. Hosted by: Hank Green SciShow is on TikTok! Check us out at https://www.tiktok.com/@scishow ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Huge thanks go to the following Patreon supporters for helping us keep SciShow free for everyone forever: Bryan Cloer, Chris Peters, Matt Curls, Kevin Bealer, Jeffrey Mckishen, Jacob, Christopher R Boucher, Nazara, charles george, Christoph Schwanke, Ash, Silas Emrys, Eric Jensen, Adam Brainard, Piya Shedden, Alex Hackman, James Knight, GrowingViolet, Sam Lutfi, Alisa Sherbow, Jason A Saslow, Dr. Melvin Sanicas, Melida Williams, Tom Mosner ---------- Looking for SciShow elsewhere on the internet? SciShow Tangents Podcast: http://www.scishowtangents.org/ Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Instagram: http://instagram.com/thescishow ---------- Sources: http://www.ijdb.ehu.es/web/paper.php?doi=11291841 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2464568/ https://www.jstor.org/stable/4330877?seq=1#page_scan_tab_contents https://www.ncbi.nlm.nih.gov/books/NBK10101/ https://opentextbc.ca/biology/chapter/24-6-fertilization-and-early-embryonic-development/ https://www.nobelprize.org/prizes/medicine/1935/spemann/lecture/ https://www.dictionary.com/browse/developmental-biology Images: https://commons.wikimedia.org/wiki/File:Hilde_Mangold.jpg https://commons.wikimedia.org/wiki/File:Zygote1.jpg https://www.istockphoto.com/vector/development-of-the-human-embryo-gm509962405-46482592 https://www.istockphoto.com/vector/pink-human-skin-cell-vector-seamless-pattern-gm1076612692-288319198 https://www.istockphoto.com/vector/cell-division-background-gm500374547-42835662 https://www.istockphoto.com/photo/frog-spawn-gm1002876014-270985943 https://commons.wikimedia.org/wiki/File:TriturusCristatusYoungLarva.JPG https://www.istockphoto.com/photo/young-businessman-getting-tired-and-depressed-working-hard-in-the-office-gm683118450-125353095 https://www.istockphoto.com/vector/phone-tablet-icon-with-tile-user-interface-on-screen-flat-style-vector-illustration-gm942687596-257620352 https://commons.wikimedia.org/wiki/File:Hans_Spemann_nobel.jpg