I don't think we can know for sure but the "outliers" may hint at hunting and gathering being more akin to genders in the sense of rolls distinct from biological sex. Like the sensationally reported "gay caveman". A similar concept exists with twospirits. Although women getting pregnant provides strategic reasons and better color and taste distinguishing would suggest a pro-gatherer bias for women worked out better or is just an accident of x-linked trait redundancy protecting against flaws there. Of course individual apitudes matter the most on a per individual basis. A colorblind woman distinguishing toxic from nontoxic plants would be at a disadvantage.

Evolution isn't goal oriented but the survival bias can shape things in a shockingly strategic way like with lactose tolerance trait/technically a mutation as seen on maps. Traditionally herdsmen regions have it higher and the swiss practically have it ubiquitously. Although with wandering there may be intelligent selection bias where the ones who would be sickened by dairy decide to risk going elsewhere.