I believe she means that with technology, cooperation, and progress, we as a species have not really been getting "weeded out" like natural selection involves. Basically anyone can live long enough to reproduce, and things that would be debilitating for an animal in the wild dont really exist for humans to the same degree. We can augment ourselves with prosthetics, medication, etc, to prolong our lives and functioning. Animals can't really do that. There's no point to saying something is human nature because we have essentially "outgrown" our natural selves, if that makes sense. Maybe I'm talking out my ass though idk im a dumbass with too much time to think about stuff like this.