Male competition can beat paternal care even when care saves many offspring.

Why do males put more energy into fighting for mates than raising children? Caring for offspring helps more of them survive to maturity. Competing gives a male the chance to father more total offspring. To understand this trade-off, researchers built a dynamic model testing the reproductive benefits of each path. They found that even when paternal carepaternal careEffort by a father to help his own offspring survive, like feeding or protecting them. strongly helps children survive, tiny competitive payoffs can outweigh the benefits of providing care. This leaves males with higher evolutionary fitness when they focus on mating competition rather than parenting across many conditions. The authors also applied their model to men competing for hunting reputations by chasing big game that feeds the whole group. In that scenario, either strategy can win depending on the group's starting mix. Crucially, the larger the shared benefit from the hunt, the more individuals evolve to supply it.

Why it matters

This matters because it helps explain why males in many species—including humans—spend energy fighting or displaying instead of raising young. The model shows that small competitive gains easily outweigh even large care benefits, so selection can favor competition. For humans, it suggests hunting for shared food might be a form of competition that looks cooperative.

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