Extreme weapons evolved independently across roughly three thousand species

Evidence

Such is the reality of extreme animal weapons. Brutal and beautiful, extreme weapons have cropped up repeatedly during the unfolding of the history of life. All told, some three thousand species now wield them. That’s a drop in the bucket considering there are 1.3 million described types of animal, but it’s a collection packed with remarkable creatures. Early champions include the horns of triceratops, titanotheres, and trilobites, the tusks of mammoths and dolphins, and the racks of Irish elk. Today, extreme weapons are wielded by walruses, antelope, whales, crabs, shrimp, beetles, earwigs, plant bugs, and flies, to name just a few. The weapons themselves can be matted hair, bone, teeth, or chitin, and they take any number of different forms. Some, for example, are overgrown versions of an existing structure, like a tooth or a leg. Others appear to have arisen de novo, as new bumps or knobs that became so large they formed their own distinct structure. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 15

Categorization

• XREF: connects to: The same three ingredients trigger weapon evolution across wildly divergent animal clades; Dung beetles offer the ideal study system for extreme weapon evolution.; Identical triggers drive extreme weapon evolution across wildly unrelated clades — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 277 (+8 more)

Related

• The same three ingredients trigger weapon evolution across wildly divergent animal clades (similarity 0.93)
• Dung beetles offer the ideal study system for extreme weapon evolution. (similarity 0.90)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.89)
• Identical triggers drive extreme weapon evolution across wildly unrelated clades (similarity 0.89)
• Animal weapons evolved to extremes far beyond practical size (similarity 0.87)
• The evolutionary drivers of animal weapons also explain human weapon elaboration. (similarity 0.87)
• Economic logic explains weapon evolution across virtually all animal species (similarity 0.86)
• Comparisons of animal and human weapons have a long scholarly tradition. (similarity 0.85)
• Biological weapons evolve through the same replication mechanism as their bearers (similarity 0.85)
• Dueling plus competition and defensibility is the general rule for extreme weapons (similarity 0.85)
• Extreme male weapons evolved independently at least eleven times in vinegar flies (similarity 0.84)
• Weapon evolution is judged by competition among designs, not human survival (similarity 0.84)
• Weapons evolve only when reproductive benefits exceed costs (similarity 0.84)
• Predator diversity is best explained by weapon adaptation to habitat and prey (similarity 0.84)
• Animal weapons can evolve rapidly within just seven generations (similarity 0.84)

Broader Connections

• Competition for reproduction drives evolution of nature’s biggest weapons #expands (0.85) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136
• Economic logic explains weapon evolution across virtually all animal species #expands (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 198
• Social competition environments evolve in tandem with weapons, unlike fluctuating physical environments #expands (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 182