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This SciShow video 'There Are More Than Two Human Sexes,' can only get away with this claim because they never actually define what sex is.
Instead, they present variations of sex-related traits, and imply that variations are new sexes. It's ideological manipulation.
THREAD... https://twitter.com/miksea3/status/1269716777799282688
Instead, they present variations of sex-related traits, and imply that variations are new sexes. It's ideological manipulation.
THREAD... https://twitter.com/miksea3/status/1269716777799282688
The fundamental definition of sex is rooted in the difference in gametes: "The origin of the two sexes is then equal to the question of why do gametes come in two different sizes."
Thus, a male is the sex which develops to support small gametes, and a female is the sex which develops to support large gametes: "Divergence into just two sexes is an almost inevitable consequence of sexual reproduction ... likely to be driven largely by gamete competition."
Any definition of sex which does not include the reason why we have a sex in the first place (namely, to support small or large gametes) is missing the mark completely.
This is where SciShow's argument relies on you not knowing what the definition of sex is.
This is where SciShow's argument relies on you not knowing what the definition of sex is.
SciShow presents variations in sex-related traits, such as chromosomes (XXY, X, XXYY), hormone production, genital morphology, and gonadal tissue.
These are not new sexes, but variations within males and within females. How do we know these variations are males and females?
These are not new sexes, but variations within males and within females. How do we know these variations are males and females?
The answer:
Individuals with these variations still develop a reproductive anatomy organized towards small gamete production or large gamete production, like everyone else.
Individuals with these variations still develop a reproductive anatomy organized towards small gamete production or large gamete production, like everyone else.
For example, XXY are males (they develop reproductive system to support small gametes).
Unique DSDs are variations of anatomy, not variations of sex. SciShow uses existing research about DSDs as evidence that there are more than two sexes. This is pseudoscientific garbage.
Unique DSDs are variations of anatomy, not variations of sex. SciShow uses existing research about DSDs as evidence that there are more than two sexes. This is pseudoscientific garbage.
Imagine having a difference in sex development, such as Congenital Adrenal Hyperplasia, and you find that your condition is being used to argue that you aren't really male or female.
Come on. This SciShow video is fraudulent bullcrap masquerading as enlightened science.
Come on. This SciShow video is fraudulent bullcrap masquerading as enlightened science.
Again, we know it's bullcrap because they never define sex. They only show variations of sex-related traits.
Of course, if they did define sex (two evolved reproductive anatomies for two gametes) then they couldn't make the argument that there are more than two sexes.
Of course, if they did define sex (two evolved reproductive anatomies for two gametes) then they couldn't make the argument that there are more than two sexes.
Thus, SciShow takes advantage of people's own scientific ignorance about how evolutionary and developmental biology defines sex.
Further, why is our sex development system so dichotomous, meaning why does our reproductive system develop towards either one of two types of gametes, and not both at the same time?
The reason why we don't have true hermaphrodites (individuals who produce both gametes) is because sex development in humans and other mammals is a mutually antagonistic system, meaning as one reproductive system develops, it automatically inhibits the other.
The mechanisms (gene expression and hormones) which develop the male (Wolffian) reproductive structure inhibit the development of the female reproductive structure, and vice-versa. Thus, as one system develops, the other system regresses.
Because of this mutually antagonistic system, there has been no human ever documented to have both functioning gonads and genitalia, and thus, there has been no human hermaphrodite.
So, just know that, if you see the SciShow video being presented, understand that:
1) They do not define sex.
2) They present decades-old research, not new scientific discoveries.
3) They 'other' people with medical conditions as not male or female.
1) They do not define sex.
2) They present decades-old research, not new scientific discoveries.
3) They 'other' people with medical conditions as not male or female.
Sources:
[1] Lehtonen, J., Parker, G. (2014). Gamete competition, gamete limitation, and the evolution of two sexes. Molecular Human Reproduction, 20(12).
[2] Cox, P., Togashi, T. (2011). The Evolution of Anisogamy, A Fundamental Phenomenon Underlying Sexual Selection.
[1] Lehtonen, J., Parker, G. (2014). Gamete competition, gamete limitation, and the evolution of two sexes. Molecular Human Reproduction, 20(12).
[2] Cox, P., Togashi, T. (2011). The Evolution of Anisogamy, A Fundamental Phenomenon Underlying Sexual Selection.
[3] Witchel, S. (2017). Disorders of sex development. Best Practice and Research in Clinical Obstetrics and Gynecology, 48, 90-102.
[4] Jones, R., Lopez, K. (2014). Chapter 5: Sexual differentiation. Human Reproductive Biology, 4th edition. Elsevier. 95.
[4] Jones, R., Lopez, K. (2014). Chapter 5: Sexual differentiation. Human Reproductive Biology, 4th edition. Elsevier. 95.
[5] Wilson, G. (2013). Third sex redux. Intersex Human Rights Australia.
