Variation in animal weapon size is explainable by species ecology and behavior.

Evidence

Eyes in male stalk-eyed flies sprout like lollipops from the sides of their heads, giving these flies an uncanny resemblance to miniature sets of barbells. Males in some species have absurdly long eyestalks, while males in very closely related species do not. As with dung beetles, we can explain this variation by looking closely at the natural history of each stalk-eyed species. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 253

Categorization

• XREF: connects to: Dung beetles offer the ideal study system for extreme weapon evolution.; Weapon size in animal species is under stabilizing selection, not open-ended directional selection — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 850; Economic logic explains weapon evolution across virtually all animal species — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 198 (+5 more)

Related

• Weapon size in animal species is under stabilizing selection, not open-ended directional selection (similarity 0.89)
• Dung beetles offer the ideal study system for extreme weapon evolution. (similarity 0.88)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.87)
• Extreme weapon size faces stabilizing, not open-ended, selection in real populations (similarity 0.86)
• Natural selection usually favors modest weapon size because cost offsets benefit (similarity 0.86)
• Species with huge weapons often show weak current selection on them. (similarity 0.86)
• Each weapon-size increase resets the competitive baseline, ratcheting populations upward (similarity 0.85)
• Predator weapons stay small because larger ones hinder hunting (similarity 0.85)
• The same three ingredients trigger weapon evolution across wildly divergent animal clades (similarity 0.84)
• Animal weapons evolved to extremes far beyond practical size (similarity 0.84)
• Sexual selection stays directionally constant while physical natural selection oscillates (similarity 0.84)
• Animal weapons can evolve rapidly within just seven generations (similarity 0.84)
• Extreme weapon size is relative to body size, not absolute (similarity 0.84)
• Weapons are better signals than body size because they vary from zero to enormous (similarity 0.84)
• Extreme weapons evolved independently across roughly three thousand species (similarity 0.83)

Broader Connections

• Weapon size in animal species is under stabilizing selection, not open-ended directional selection #expands (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 850
• Animal weapons evolved to extremes far beyond practical size #contradicts (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 2
• Extreme weapon size faces stabilizing, not open-ended, selection in real populations #expands (0.60)
• Natural selection usually favors modest weapon size because cost offsets benefit #expands (0.55) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 21
• Economic logic explains weapon evolution across virtually all animal species #corroborates (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 198
• Social competition environments evolve in tandem with weapons, unlike fluctuating physical environments #qualifies (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 182