system
Given the following post, respond as if you're commenting on Reddit:
human
CMV: Biological traits unique to men are entirely caused by men's reproductive expendability. Patriarchal society is a side effect.

Here's my theory: As a primitive society, your reproductive engine is entirely bottlenecked by the number of women you have. 

50 men + 50 young women == 50 babies

1 man + 50 young women == 50 babies (and one very happy guy)

More is better, of course (genetic diversity, men can be helpful, etc), but I would say the driving force causing sexual dimorphism is *the ways men can be helpful by taking the lion's share of collective risk*.

Men are biologically warriors because their deaths are less impactful on the tribe, so it's their primitive role to carry out risk and violence.

* Beards for padding punches
* Extra tall, longer limbs (no need to be lower to the ground for the anatomical changes of pregnancy, better to be faster and have longer reach)
* Testosterone motivated behavioral changes such as
   * Risk taking behavior
   * Aggression
* More lean muscle development
* Faster metabolisms (moving, carrying, fighting, whereas women serve the tribe better by staying still/safe and consuming less calories)

I can't really think of any male-specific traits that can't be connected to expendability 

Women are the natural intellectual leaders the way human's have evolved and that's why many early tribal societies were matriarchal. It doesn't make sense, strategically, to have critical leadership roles filled by men when they're more likely to die.

Patriarchy seems, then,  like a byproduct of the agricultural revolution, when territory control allowed for crop yield, power projection, dominion, and wars/consolidation of violence became relevant, and men's roles became more significant in the welfare of a people.

&#x200B;

I'm not an anthropologist, or any -ologist, just some dude who read "Selfish Gene," "Guns, Germs, Steel," and some Yuval Harari and now thinks he knows stuff.
gpt
>Beards for padding punches

A defensive measure is the opposite of expendability.

>Extra tall, longer limbs (no need to be lower to the ground for the anatomical changes of pregnancy, better to be faster and have longer reach)

Again, a phsycial advantage has nothing to do with expendability.

>More lean muscle development  
>  
>Faster metabolisms (moving, carrying, fighting, whereas women serve the tribe better by staying still/safe and consuming less calories)

Neither of these has anything to do with expendability. That's just a physical advantage, that is helpful almost always.

>Women are the natural intellectual leaders the way human's have evolved and that's why many early tribal societies were matriarchal.

There is basically zero indication that early tribal societies where matriarchal.  The opposite actually, tribal societies we have records of vary from egalitarian, to patriarchal. There are no generally agreed upon instances of a matriarchy.