All animals, are you sure? Some female spiders eat their male counterparts after mating, and not just spiders. Female lioness hunt a pack and the male ones are known to be more lazy. Many animal species have homosexuality built in, where men can team up to take care of a baby from a stolen couple and many have sex and/or mate. The genetic make up has 25 different gender markers that compose a vast array of cognitive and behavioral differences beyond what is physically man/woman, and physical characteristics are not simply divided either. Anywhere from .8 to 1.2 percent of people are born with physically ambiguous genitalia and traits, call Intersex.
Governments do not recognize them and traditionally doctors have chopped baby parts at birth to force societal conformity contradicting physical genetic traits. Physical reality was denied over conforming beliefs at the expense of babies actual self. That forced conformity has created unrelenting conservative beliefs that the world is physically man/woman and gender roles spring from that. It is also not physically true. 1 percent might not sound like a lot to you, but that is 14 million people in China and 3.4 million in the US. You can’t tell those people they are worthless and will just have to conform and their physical genetic structure of their body is meaningless and unimportant. To them it is everything; it is their daily existence. The idea that “both roles” come from a forced belief programmed into your mind shouldn’t ruin their lives.
The physical reality of these is not an experiment. Like the government, you will simply dismiss this comment that is scientifically back and physically recognizable at birth by attending physicians. Forcing people into what you think of a “natural genetic makeup” only shows a wider belief not informed by the physical reality of other people’s bodies and scientifically proved actual genetics. I don’t blame you for this flattened dualistic belief that oversimplifies physical reality and genetic truth. It is a global pattern of war based masculinity over the millennia shaped by conforming laws built by humans to be easily recognizable. Humanity has previously enforced those oversimplified roles on animals, but modern studies in nature don’t hold them to be true and distinguish many differences in species. Birds don’t “mate for life” physically, meaning many females sleep around during mating season, “cheating” on their “spouse.”
The list goes on behavioral differences and genetic differences that include the “eternal” Japanese jellyfish that gives birth to itself. The evolutionary changes demanded by thousands of harsh environmental conditions force species to adapt their mating, reproduction and physical make up to conform to it, not conform to the vastly oversimplified human political reality of man/woman found on the battlefield. Humanity is the only specifies it seems to force the environment to impose its’ beliefs on it and not the other way around.