Is it possible that Y Chromosomes might actually disappear from genetic code? What would happen to species as we know them? We're generally taught that chromosomes determine an animal's sex, but turns out, it is way more nuanced than that. Learn what's going on in this new episode of SciShow, hosted by Rose Bear Don't Walk! 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: 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 ------- 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 ---------- 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: 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 ---------- 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: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4077654/ https://www.nature.com/scitable/definition/recombination-226/ https://www.ncbi.nlm.nih.gov/books/NBK10008/ https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_Introductory_Biology_(CK-12)/02%3A_Cell_Biology/2.39%3A_Genetic_Variation https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_General_Biology_(Boundless)/19%3A_The_Evolution_of_Populations/19.2%3A_Population_Genetics/19.2A%3A_Genetic_Variation https://jmg.bmj.com/content/jmedgenet/22/3/164.full.pdf https://www.nature.com/scitable/topicpage/genetic-mechanisms-of-sex-determination-314/ https://www.nature.com/scitable/topicpage/nettie-stevens-a-discoverer-of-sex-chromosomes-6580266/ https://www.journals.uchicago.edu/doi/10.1086/352001 https://embryo.asu.edu/pages/studies-spermatogenesis-1905-nettie-maria-stevens https://www.gutenberg.org/files/31545/31545-h/31545-h.htm https://academic.oup.com/mbe/article/29/6/1645/999408 https://academic.oup.com/gbe/article/12/6/750/5823304 https://www.journals.uchicago.edu/doi/full/10.1086/698198 https://royalsocietypublishing.org/doi/10.1098/rstb.2016.0456 https://www.genetics.org/content/207/2/711 https://www.ncbi.nlm.nih.gov/books/NBK10943/ https://www.ncbi.nlm.nih.gov/books/NBK279001/ https://academic.oup.com/jhered/article/108/1/78/2631559 https://www.nature.com/articles/nature03021 https://pubmed.ncbi.nlm.nih.gov/21967422/ https://www.ncbi.nlm.nih.gov/books/NBK9989/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4077654/ https://academic.oup.com/icb/article/49/6/730/629874 https://medlineplus.gov/genetics/gene/sry/ https://www.genetics.org/content/207/2/711 https://www.nature.com/articles/s41598-020-58997-2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5704219/ https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/wnt4 https://medlineplus.gov/genetics/gene/wnt4/ https://commons.wikimedia.org/wiki/File:Aristotle_Altemps_Inv8575.jpg https://en.wikipedia.org/wiki/File:Nettie_Stevens.jpg https://en.wikipedia.org/wiki/Gregor_Mendel#/media/File:Gregor_Mendel_2.jpg https://commons.wikimedia.org/wiki/File:Ideogram_human_chromosome.svg https://commons.wikimedia.org/wiki/File:Nettie_Stevens_microscope_(2).jpg https://commons.wikimedia.org/wiki/File:XY_chromosomes.png https://www.istockphoto.com/photo/quail-eggs-in-the-nest-gm517752906-89663599 https://www.istockphoto.com/photo/platypus-young-gm1220729124-357558396 https://www.istockphoto.com/photo/cardinal-in-spruce-tree-gm1312384073-401211378 https://commons.wikimedia.org/wiki/File:Rana_rugosa_by_OpenCage.jpg https://www.istockphoto.com/photo/fertilization-of-human-egg-cell-by-spermatozoan-gm622767176-109048913 https://en.wikipedia.org/wiki/Northern_mole_vole#/media/File:Ellobius_talpinus.jpg https://www.storyblocks.com/video/stock/dna-sequencing-the-bases-of-a-fragment-of-dna-abstract-background-skx-uxydpkgvmnshp