“ There's also one molecular biologist who claimed similar on twitter (it gets copy-pasted around a lot) making a pretty embarrassing statistics error confusing dependent and independent variables.
Michelle Gael, this source does the same thing. Mostly it talks about gender and not sex, but it is indeed explicitly claiming: "For all too long, the government, the medical system, and even our parents have assumed that sex is binary. Based on science, this is not biologically or medically accurate.
What is true is that sex characteristics tend to be bimodal, meaning there are clusters of characteristics that tend to be associated with people that we call “female” or “male.”"
This is the same error of confusing dependent and independent variables. Specifically it's confusing sex with variables which are correlated with sex. Take, for example, hormonal levels. Hormone levels are correlated with sex, pretty much in that standard continuous bimodal fashion, but that doesn't mean hormone levels _define_ sex, hormone levels are just one of many variables that are _correlated_ with sex. Sex is _defined_ by gamete type, a hormone level isn't a gamete type.
It's easy to see this by considering the binary set {0, 1} (that which computers work with). This is as binary as it gets. Yet, there are continuous overlapping bimodal variables which are correlated with this set. Many people have different handwriting, so for example "roundness" would be a variable correlated with {0, 1} that is on a continuous bimodal distribution. Yet that doesn't stop the set {0, 1} from being binary, it's just the "roundness" variable that is continuous.
Similarly, a hormone level might be a bimodal distribution correlated with sex, but a hormone level isn't a gamete type. Chromosomes is a bimodal distribution correlated with sex, but a chromosome isn't a gamete type, etc.”
actually Anne Fausto-Sterling does regularly make such claims, she's pretty known for this. One has to understand that she's really a gender studies professor with a second degree in biology and has a habit of making claims in biology solely for ideological purposes in her gender studies work. It got so far out of hand that last year she retracted her claims of there being more than 2 sexes claiming it has just been a joke. https://twitter.com/SwipeWright/status/1229876565548376065
Charles Brown
> wrote:
Gregory Lucero that’s not what defines sex. Eggs or sperm do. All of those combinations are either eggs or sperm phenotypes ( or infertile ) ; there’s no third type . Sex is of course only two complementary opposite types in sexually reproducing species. One of each required for fertile sex. No third type required or able to be part of reproduction. Anthropology includes human evolution, biology. I _teach_ biology .
Sex is the trait that determines whether a sexually reproducing animal or plant produces male gametes or female ones.[1][2] Male plants and animals produce smaller gametes (spermatozoa, sperm) while females produce larger ones (ova, often called egg cells).[3] Organisms that produce both types of gametes are called hermaphrodites.[2][4] During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent.
Males and females of a species may have physical similarities (sexual monomorphism) or differences (sexual dimorphism) that reflect various reproductive pressures on the respective sexes. Mate choice and sexual selection can accelerate the evolution of physical differences between the sexes.
The terms male and female typically do not apply in sexually undifferentiated species in which the individuals are isomorphic (look the same) and the gametes are isogamous (indistinguishable in size and shape), such as the green alga Ulva lactuca. Some kinds of functional differences between gametes, such as in fungi,[5] may be referred to as mating types.[6]
A living thing's sex is determined by its genes. Most mammals have the XY sex-determination system, where male mammals carry an X and a Y chromosome (XY), whereas female mammals carry two X chromosomes (XX). Other chromosomal sex-determination systems in animals include the ZW system in birds, and the X0 system in insects. Various environmental systems include temperature-dependent sex determination in reptiles and crustaceans.[7]
https://m.youtube.com/watch?v=CuxaXghfyeE
https://en.wikipedia.org/wiki/Sex
https://en.wikipedia.org/wiki/Biological_anthropology .
Biological anthropology, also known as physical anthropology, is a scientific discipline concerned with the biological and behavioral aspects of human beings, their extinct hominin ancestors, and related non-human primates, particularly from an evolutionary perspective.[1] This subfield of anthropology systematically studies human beings from a biological perspective.
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