So if i have a shirt with male birds on it, is it a ZZ Top?

BA-DUM-TSS!! 🥁

You will be sharp dressed. It will highlight your legs.

Fasincating; you know how human females are (XX) and males (XY)? You also know how all humans are first female and then if you have the Y your body starts changing into male?

I have always seen the above two facts as meaning that in a real sense we are a female species that has male variants. I wonder if birds start out in their eggs as male and then differentiate into females if they have the W chromosome.

Whereas sex with birds is determined by whether they're sleeping or not when I sneak up on them.

Is there a Z-inactivation gene in male birds the same way there is X-inactivation in female mammals?

Wow didn't know that. How did you see it in real time?

Sequencial hermaphroditism is also pretty interesting.

> In contrast to the XY sex-determination system and the X0 sex-determination system, where the sperm determines the sex, in the ZW system, the ovum (egg) determines the sex of the offspring.

Intriguing. Thanks for sharing that!

That's not how it works. There's a default human form with shared characteristics but the embryo is created either XX or XY. Right from the beginning these genes start to direct development, that's why even at an early age male and female children have differences even though their bodies are very similar.

The fact that men have nipples is often used as proof of a female template, but that's just a shared characteristic. Humans start with the same set up and then the basic form is developed as necessary. The same argument about nipples could be made for hips and knees. The human template is obviously male because males have similar hips and knees their whole lives, but women's hips and knees change profoundly during puberty. That doesn't mean we're a male species, just that having "male" hips and kness doesn't hinder a woman and having "female" nipples doesn't hinder a man.

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u/treeofliife

Wait, how are a woman's knees different than a man's knees?

According to https://mountainview-hospital.com/newsletter/women-weaker-in-the-knees-than-men.dot the angle is sharper due the wider hips

Sexual reproduction, specifically males and females, vastly predates human beings. Both sexes are a natural requirement for the species to exist.

You may find it interesting how nest temperature determines reptile sex.

https://embryo.asu.edu/pages/temperature-dependent-sex-determination-reptiles

There are lots of structural differences like that. These differences contribute to female athletes being much more prone to certain injuries.

“Gender Differences Mean More Knee Injuries for Women“

https://www.cedars-sinai.org/blog/gender-differences-knee-injuries.html

Conservatives absolutely fuming right now

Thanks for tagging me 🙏