Sexual selection drives weapons to extremes because payoffs for winners are enormous.

Evidence

Sexual selection differs from most forms of natural selection in ways tailor-made for pushing traits to their extreme. For one thing, sexual selection can be a lot stronger than natural selection. Whenever a small subset of males monopolizes access to large numbers of females, the disparity in reproductive success skyrockets. A few victorious males sire dozens or even hundreds of offspring, while the overwhelming majority of males sire none. When payoffs for success are high enough, weapons can evolve to really big sizes. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 177 (#corroborates, via linked claim)

In the animal world, extreme weapons are usually confined to specific, rare circumstances such as sit-and-wait hunting tactics, or within-colony division of labor. But another surprisingly potent phenomenon can lead to the evolution of exaggerated weapon sizes: competition. Nature’s biggest weapons decide the outcomes of battles over the chance to reproduce, the most precious commodity of all. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Extreme skew in mating success drives arms-race escalation in weaponry; Successful cheaters can reverse selection so big weapons collapse; Sexual selection can be far stronger than natural selection and drives weapon extremes — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 177 (+13 more)

Related

• Sexual selection can be far stronger than natural selection and drives weapon extremes (similarity 0.96)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.95)
• Extreme skew in mating success drives arms-race escalation in weaponry (similarity 0.93)
• Extreme weapon size faces stabilizing, not open-ended, selection in real populations (similarity 0.90)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.90)
• Balanced selection keeps most animal weapons modest rather than extreme. (similarity 0.90)
• Weapon costliness keeps signals honest by excluding weaker males (similarity 0.89)
• Successful cheaters can reverse selection so big weapons collapse (similarity 0.89)
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races (similarity 0.89)
• When balancing selection fails, bigger weapons win every round and escalate the race. (similarity 0.89)
• Natural selection usually favors modest weapon size because cost offsets benefit (similarity 0.88)
• Deterrence amplifies the evolutionary payoff of extreme weapon size. (similarity 0.88)
• Cheating males erode the reproductive payoff of weapons, capping their evolution (similarity 0.88)
• Weapon size in animal species is under stabilizing selection, not open-ended directional selection (similarity 0.88)
• Sexual selection is uniquely directional because the social environment itself evolves with the weapons (similarity 0.88)

Broader Connections

• Sexual selection can be far stronger than natural selection and drives weapon extremes #corroborates (0.90) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 177
• Competition for reproduction drives evolution of nature’s biggest weapons #corroborates (0.85) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136
• Reproductive success, not survival, drives the largest animal weapons #corroborates (0.85)
• Deterrence amplifies the evolutionary payoff of extreme weapon size. #expands (0.75) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 387
• Natural selection usually favors modest weapon size because cost offsets benefit #complicates (0.75) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 21
• Extreme weapon size faces stabilizing, not open-ended, selection in real populations #contradicts (0.75)
• Cheating males erode the reproductive payoff of weapons, capping their evolution #qualifies (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 851
• Dueling plus competition and defensibility is the general rule for extreme weapons #expands (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 266
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races #contradicts (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 22
• Growing large weapons diverts resources and stunts other body parts #qualifies (0.65) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295
• Weapon size is favored when males defend resources females need #expands (0.65) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 960
• Sexual selection is uniquely directional because the social environment itself evolves with the weapons #expands (0.60)
• Males evolve big weapons to defend resources that females visit #expands (0.60)
• Weapons in arms races get so big they impair other bodily functions #qualifies (0.60)