Source: File:Praying Mantis Sexual Cannibalism European-37.jpg, GNU Free Documentation License 1.2, via Wikimedia Commons
Evolution and "survival of the fittest" does not care about fairness.
Concepts such as fairness, justice, and liberty have no application to individuals in the jungle. In the jungle, the only thing that matters is surviving and producing offspring who also survive and produce offspring. In the jungle, the only thing that matters is what works. Whenever you catch yourself thinking about how life is unfair, recall this image of a female preying mantis eating the male who approached to copulate with her:
Such concepts also have no application to villages in the jungle. When a village is destroyed by another village contesting for control of the same land, game, and potable water, it is not useful to say, "Unfair!" For villages in the jungle, as for individuals, the only thing that matters is what works.
Concepts such as fairness, justice, and liberty incorporated into the way of life of a village can give that village a competitive advantage. A way of life with these features can enable a village to inspire loyalty, reduce conflict, and unite the village. But these concepts are only the means to the end of prospering the village. They cannot be ends in themselves, because a village, as a coalition, has only wo objective: win at the game of life presented by the jungle.
Whether a village's way of life is fair does not directly matter; the only thing that matters is whether it works! The way of life must work for the village as a whole. It must also work well enough for each villager to retain the villager in the coalition. A woman, for example, must be as well off in the village as she would be if she emigrated to another village.