Dueling plus competition and defensibility is the general rule for extreme weapons

Evidence

Together with competition and economic defensibility, duels tip the evolutionary balance in favor of extreme weapons. This simple insight has terrific explanatory power because it provides a general rule for why particular animal species have extreme weapons, and why their close relatives may not. Like uncovering the key to an ancient encrypted cipher, we can now make sense of so much animal diversity. Specifically, we can look to the histories of groups of species to see when behaviors changed in ways that caused the arms race ingredients to fall into place. This can help explain why isolated species stand out from the rest, and it can also explain why whole groups of related species appear to enter into arms races together. Sometimes, one or more of the arms race ingredients are part of the inherited physiology of a group of species, and this can predispose them all to arms races. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 266

Categorization

• XREF: connects to: Concentrating simultaneous fire disfavors large weapons while duels favor them; When balancing selection fails, bigger weapons win every round and escalate the race.; Three conditions must align to trigger an animal weapons arms race. (+10 more)

Related

• Specific conditions are required before weapons escalate into an arms race (similarity 0.92)
• When balancing selection fails, bigger weapons win every round and escalate the race. (similarity 0.91)
• Three conditions must align to trigger an animal weapons arms race. (similarity 0.91)
• Deterrence amplifies the evolutionary payoff of extreme weapon size. (similarity 0.90)
• Big weapons only pay off when fights are one-on-one duels (similarity 0.90)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.89)
• Concentrating simultaneous fire disfavors large weapons while duels favor them (similarity 0.88)
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races (similarity 0.88)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.88)
• Intense competition without duel structure does not drive weapon evolution. (similarity 0.88)
• Specific ecological circumstances must align before weapon arms races begin (similarity 0.88)
• Weapon evolution needs both competition and economically defensible resources (similarity 0.88)
• Species with huge weapons often show weak current selection on them. (similarity 0.88)
• Weapon size in animal species is under stabilizing selection, not open-ended directional selection (similarity 0.87)
• Sexual selection can be far stronger than natural selection and drives weapon extremes (similarity 0.87)

Broader Connections

• Weapon evolution needs both competition and economically defensible resources #corroborates (0.90) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 191
• Deterrence amplifies the evolutionary payoff of extreme weapon size. #corroborates (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 387
• Losing the ecological context of competition can make extreme weapons vanish. #expands (0.55) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 438
• Extreme weapon size faces stabilizing, not open-ended, selection in real populations #contradicts (0.50)
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races #complicates (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 22