This article by Liza Brusman is available in English and Spanish, text or read loud.
TED Talk: "The way we think about biological sex is wrong" by Emily Quinn
Emily Quinn, an intersex activist, delivered this 14-minute talk at the TedWomen 2018 event. Emily tells her personal story and discusses the little-known truth that biological sex is a spectrum and not a binary. This is true whether we measure biological sex by chromosomes, hormones, gonads, or external genitalia. She dispels the myth of intersex people as extremely rare outliers, and humanizes diversity in biological sex.
It's rare to meet an intersex person that hasn't been operated on. Oftentimes, these surgeries are done to improve intersex kids' lives, but they usually end up doing the opposite, causing more harm and complications, both physical and emotional. I'm not saying that doctors are bad or evil. It's just that we live in a society that causes some doctors to "fix" those of us who don't fit their definition of normal. We're not problems that need to be fixed. We just live in a society that needs to be enlightened.
This video is uploaded to Youtube but its mature content tag makes it inaccessible through some school internet filters. Alternatively, TED.com page contains the video, transcript in 24 languages, and further reading list.
Gynandromorph Animals - BBC Earth article
This BBC Earth article explores the rare phenomenon of bilateral gynandromorphs, or animals which develop different physical sex characteristics on their left and right side. This occurs when a cycle of meiosis yields multiple viable eggs rather than one egg and three polar bodies to be discarded. When two eggs are fertilized by sperm, mosaicism can occur in the sex chromosomes.
When introducing students to the article, the teacher should be sure to note that overgeneralizing language is briefly used to describe humans (“In humans, men have an X and a Y chromosome, while women have two X chromosomes.”) However, the article can still have value in demonstrating the nonbinary nature of biological sex and the scientific processes by which evidence is gathered to support this.
A Reddit post shows a gynandromorph lobster found in the wild:
Gender and Sex – Transgender and Intersex (Book Chapter)
This UMass Amherst textbook chapter models the use of precise, modern, and non-pathologizing language for discussing transgender and intersex topics in the context on human biology. The textbook authors are Miliann Kang, Donovan Lessard, Laura Heston, and Sonny Nordmarken. The chapter is available through Openbooks under a Creative Commons Attribution license.
A Biology Teacher Just Destroyed Every Excuse for Transphobia With Cold, Hard Facts (Observer)
A few of the facts that biology teacher Grace Pokela shares:
sex chromosomal variety: Insects use an XO sex determination system, while birds use the ZW system.
environmental factors for sex: A reptile’s sex is at least partly determined by the temperature in which the egg develops.
hermaphroditism: Flatworms transfer sperm through a process called penis fencing (which is described in graphic detail here).
hermaphroditism & sex change: In clownfish colonies, dominance is based on size, the female being the largest and the male being the second largest. If the female dies, the male gains weight and becomes the female for that group.
Editor’s note: The term "hermaphrodite" is appropriate for referring to non-human animals with sex characteristics that do not fit typical binary notions of male or female bodies. For humans, “intersex” is the appropriate term—learn more here!
transgender behavior: Other fish species take on female attributes while mating, and they release sperm in the process.
2+ sexes: Fungi like molds and mushrooms have 36,000 sexes.
In humans, 5-alpha-reductase deficiency is a real (albeit rare) condition, in which young women grow a penis during puberty.
In humans, androgen insensitivity syndrome (AHS) is an intersex condition in which a person who is genetically male is resistant to male hormones . As a result, the person has some or all of the physical traits of a woman, but the genetic makeup of a man.
In humans, the SRY gene is involved in male sexual development—without it fetuses can be genetically male (with XY chromosomes) but have a female body. The same is true in females (with XX chromosomes), who can develop a male body without the SRY gene.
In humans, XXY males are sterile, with small testes—while women with only one X chromosome (a condition called Turner syndrome) are infertile and don’t go through puberty. Males with two X chromosomes (called Klinefelter syndrome) are taller, with a higher risk of breast cancer and osteoporosis.
Read more at https://observer.com/2017/03/transgender-facebook-troll-biology-sexuality/
“Receiving [information to counter gender stereotyping] at an early age is critical; there has been a steady decline in the average age at which puberty begins..." (NYT & PNAS 2015)
“Receiving [information designed to counter gender stereotyping] at an early age is critical. There has been a steady decline in the average age at which puberty begins. Among those assigned female at birth, some breast development by age seven and eight is no longer an anomaly. The age of the onset of puberty has also fallen for those assigned male at birth, from an average of age 11 to 10.5.”
Tabuchi, H. (2015) “Sweeping Away Gender-Specific Toys and Labels” The New York Times. Retrieved on January 23, 2019 from https://www.nytimes.com/2015/10/28/ business/sweeping-away-gender-specific-toys-and-labels.html
Joel, D et al. (2015) “Sex beyond the genitalia: The human brain mosaic.” Proceedings of the National Academy of Sciences. Dec 2015, 112 (50) 15468-15473