A prominent theoretical physicist faced severe backlash after sharing a widely-debunked representation of biological sex as a “spectrum.”
Sean M. Carroll, who specializes in quantum mechanics and teaches philosophy at John Hopkins University, tweeted on Sunday his dissension with an evolutionary biologist’s statement of biological sex being “real, immutable, and binary.” Caroll, invoking “actual science,” as he called it, shared an infographic from the 2017 Scientific American article, “Visualizing Sex as a Spectrum.” The deluge of critical responses to his ill-fated tweet caused Carroll to turn off comments.
“‘Actual science’ done by biologists shows 2 sexes, one with small mobile gametes and the other with large, immobile ones,” said renowned evolutionary biologist Jerry Coyne in response. “There is no third sex. Disorders of sex development are not new sexes, and biological sex is binary. Let’s not conflate sex, gender & developmental anomalies.”
"Actual science" done by biologists shows 2 sexes, one with small mobile gametes and the other with large, immobile ones. There is no third sex. Disorders of sex development are not new sexes, and biological sex is binary. Let's not conflate sex, gender & developmental anomalies. https://t.co/tANXZM5S0r
— Jerry Coyne (@Evolutionistrue) November 14, 2022
The infographic, commonly touted by trans activists as a refutation to the longstanding binary model of sex, relies on the existence of intersex conditions to argue that biological sex is best visualized as a “spectrum.” This infographic depicts a small number of discrete disorders of sexual development (DSD), or “intersex conditions,” arbitrarily placed between female and male.
“This chart is a futile attempt to pretend sex is a spectrum by taking a handful of DSDs and lining them up in a nonsensical order that in no way reveals a spectrum,” said developmental biologist Emma Hilton.
Intersex conditions are genetic abnormalities resulting in sexually ambiguous genitalia that affect about 0.018% of the population. The existence of these developmental sex differences does not negate that sex is a binary system comprised of males and females.
Some of the intersex conditions were “irrationally” placed further apart with arrows extending across the graphic and crossing each other to “generate the illusion of complexity,” said Hilton.
Intersex conditions have absolutely no bearing on gender self-identification, and people with DSD have even asked that their condition not be “appropriated” for the purpose of transgender activism. Despite this, intersex conditions are often touted by activists to claim that sex is a spectrum, and their numbers are frequently incorrectly inflated to 1.7%, or “as common as red hair.”
“Humans are a species with precisely two sexes, no more and no less,” said Zach Elliott, a science educator who specialized in sex differences. “This means that there are exactly two distinct reproductive roles—referred to as male and female—centered around the production of two gametes of differing size (a form of sexual reproduction known as anisogamy).”
Evolutionary biologist Heather Heying chimed in on Tuesday to reiterate that sex, indeed, is a binary system.
Scientific American, the publication that produced the sex spectrum graphic, was a once respected popular science magazine that veered off into a leftist tabloid in recent years. Michael Shermer, who had a “Skeptic” column at Scientific American for 18 years, details the magazine’s long-running departure from science and reason, beginning in about 2019.
“The interchange between Michael and his editors gives us some insight into the termites chewing into the edifice of Scientific American,” Coyne wrote on his website, Why Evolution is True. “My prediction is that unless the editors go back to its original format and lay off the propagandizing, the magazine will fold. After all, you can read about social justice and wokeness nearly everywhere, including Teen Vogue, but Scientific American was once unique.”
Steven Novella, a popular science blogger, proposed an equally unscientific model of “bimodal” sex in July, despite the fact that no peer-reviewed biology papers have ever claimed that sex is best described as bimodal, nor has any biologist ever been able to articulate the traits and measurements used to create the bimodal sex spectrum. In Novella’s article, he surreptitiously cites studies of crustaceans and mice to explain sexual differences, without properly informing the reader that he isn’t speaking about human biology or development.