> Gender in humans isn’t fundamentally different.
It is fundamentally different.
The range of behaviors that Humans have is fundamentally far, far more broad than animals, because we are much more intelligent creatures. Example from a few thousand years ago: Farming, Cooking food. More recent examples: Fixing cars, doing taxes. Most of what Humans spend their time doing these days are things that animals don't do in nature.
Human cultures like to ascribe gender roles to most of these things, but in reality most of what people do doesn't have any implicit gender role associated with it, since it's pretty far removed from biological functions at this point.
Even in nature, the things people and animals do doesn't always neatly align with gender roles. For example, child rearing or even bearing live young is sometimes done by the male, even though it's usually a female gender role.
What's different between us and animals (as is usually the case) is our big thinky brains, and the things which follow on from that.