We're generally taught that chromosomes determine an animal's sex, but it is way more nuanced than that. 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 ---------- 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 ---------- 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/PMC1660543/ 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://www.istockphoto.com/photo/bees-on-honeycomb-with-bee-uterus-gm957010644-261312110 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