Reproductive success, not survival, drives the largest animal weapons

Evidence

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)

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)

Categorization

• XREF: connects to: Balanced selection keeps most animal weapons modest rather than extreme.; Sexual selection drives weapons to extremes because payoffs for winners are enormous.; Competition for reproduction drives evolution of nature’s biggest weapons — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136 (+9 more)

Related

• Sexual selection drives weapons to extremes because payoffs for winners are enormous. (similarity 0.95)
• Sexual selection can be far stronger than natural selection and drives weapon extremes (similarity 0.94)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.93)
• Weapon size in animal species is under stabilizing selection, not open-ended directional selection (similarity 0.90)
• Extreme skew in mating success drives arms-race escalation in weaponry (similarity 0.90)
• Extreme weapon size faces stabilizing, not open-ended, selection in real populations (similarity 0.90)
• Deterrence amplifies the evolutionary payoff of extreme weapon size. (similarity 0.90)
• Bigger weapons usually fail because their costs outweigh their benefits (similarity 0.90)
• Balanced selection keeps most animal weapons modest rather than extreme. (similarity 0.90)
• Weapons evolve only when reproductive benefits exceed costs (similarity 0.89)
• Natural selection usually favors modest weapon size because cost offsets benefit (similarity 0.89)
• Dueling plus competition and defensibility is the general rule for extreme weapons (similarity 0.89)
• Species with huge weapons often show weak current selection on them. (similarity 0.88)
• Each weapon-size increase resets the competitive baseline, ratcheting populations upward (similarity 0.88)
• Big weapons only benefit males with the reserves to wield them effectively (similarity 0.88)

Broader Connections

• Competition for reproduction drives evolution of nature’s biggest weapons #corroborates (0.90) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136
• Sexual selection can be far stronger than natural selection and drives weapon extremes #corroborates (0.80) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 177
• Extreme skew in mating success drives arms-race escalation in weaponry #corroborates (0.70)
• Weapons evolve only when reproductive benefits exceed costs #expands (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199
• Males evolve big weapons to defend resources that females visit #expands (0.60)
• Animal weapons evolved to extremes far beyond practical size #expands (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 2
• Deterrence amplifies the evolutionary payoff of extreme weapon size. #expands (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 387
• Growing large weapons diverts resources and stunts other body parts #complicates (0.40) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295