Weapon evolution needs both competition and economically defensible resources

Evidence

In a sense, males compete with rival males regardless of whether sexual selection proceeds through female choice or male competition and, in many respects, the process—the intensity, consistency, and social nature of selection—is the same regardless. Why, then, do some species embark on a trajectory of overt competition leading to the evolution of weapons, while others end up dancing or singing with displays? Here is where the ingredients for arms races come into play, for these are the pieces that must fall into place if sexual selection is to trigger evolution of extreme weapons. The first ingredient is competition, the essence of all sexual selection. The second is economic defensibility. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 191

Categorization

• DEFINE: Introduces ‘economic defensibility’ as the second ingredient required for weapon evolution.
• corroborated: 2 independent passages support this claim — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 191
• XREF: connects to: Weapons disappear when fights stop being duels over defensible resources; Markets and battlefields select among rifle designs like natural selection acts on weapons; When balancing selection fails, bigger weapons win every round and escalate the race. (+19 more)

Related

• Weapons evolve only when reproductive benefits exceed costs (similarity 0.91)
• Specific conditions are required before weapons escalate into an arms race (similarity 0.91)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.90)
• Specific ecological circumstances must align before weapon arms races begin (similarity 0.89)
• Markets and battlefields select among rifle designs like natural selection acts on weapons (similarity 0.89)
• Social competition environments evolve in tandem with weapons, unlike fluctuating physical environments (similarity 0.89)
• Weapons disappear when fights stop being duels over defensible resources (similarity 0.88)
• Dueling plus competition and defensibility is the general rule for extreme weapons (similarity 0.88)
• Intense competition without duel structure does not drive weapon evolution. (similarity 0.88)
• Sexual selection can be far stronger than natural selection and drives weapon extremes (similarity 0.88)
• Economic logic explains weapon evolution across virtually all animal species (similarity 0.87)
• Force superiority within a territory requires organized mobilization of resources (similarity 0.87)
• Losing the ecological context of competition can make extreme weapons vanish. (similarity 0.87)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.86)
• Weapon evolution is judged by competition among designs, not human survival (similarity 0.86)

Broader Connections

• Economic logic explains weapon evolution across virtually all animal species #expands (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 198
• Uniformly distributed resources make territorial weapons uneconomical #exemplifies (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 201
• Weapons evolve only when reproductive benefits exceed costs #corroborates (0.65) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199
• Competition for reproduction drives evolution of nature’s biggest weapons #expands (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136
• Intense competition without duel structure does not drive weapon evolution. #qualifies (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 242