Armor evolution tracks a benefit-cost trade-off identical to that shaping animal weaponry

Evidence

From the beginning, the evolution of protective manufactured armor was shaped by a balance between benefits and costs. As weapons became more dangerous, the thickness and toughness of armor increased, but so did its bulk and weight. On the one hand, armor could protect a soldier, but on the other it restricted his movements and slowed him down. A suit of chain mail weighed up to fifty pounds, not counting the heavy leather beneath it. A helmet alone could weigh twenty pounds, and helmets were so hot and suffocating that knights generally carried them on the pommel of their saddles until the last minutes before battle. Plate armor was a huge burden; getting knocked over or unhorsed could mean death for a knight, since he couldn’t get back up without assistance. By the end of the sixteenth century, crossbows and longbows had already called the efficacy of armor into question (arrows striking straight-on could penetrate), and the spread of gunpowder sealed its fate. As with the bony plates of lake-bound sticklebacks, once the benefits disappeared, armor was no longer worth the price. Although plate armor thick enough to stop a bullet was possible, nobody could wear it because the plates were too ungainly and heavy. So body armor all but disappeared from the battlefield for four hundred years, until a new invention: Kevlar. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 62

Categorization

• XREF: Directly parallels the stickleback armor discussion in this same book’s earlier chapters — animal and human armor evolve under the same cost-benefit logic. — connects to: The evolutionary drivers of animal weapons also explain human weapon elaboration. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 7; Balanced selection keeps most animal weapons modest rather than extreme.; Weapons innovations trigger arms races in ships just as in animals — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 962 (+13 more)
• SEED: An essay on how military technology obsolescence (plate armor, and today’s body armor) follows the same evolutionary trade-offs as animal defensive weaponry.

Related

• Weapons shrink when predator pressure falls and armor gets costly. (similarity 0.86)
• Each advance in weapon metallurgy forced a corresponding advance in protective armor (similarity 0.85)
• Weapons evolve only when reproductive benefits exceed costs (similarity 0.84)
• The evolutionary drivers of animal weapons also explain human weapon elaboration. (similarity 0.84)
• Human and animal arms races follow parallel evolutionary dynamics (similarity 0.83)
• Weapon evolution is judged by competition among designs, not human survival (similarity 0.83)
• Human fortifications and artillery evolve via the same arms-race logic as animal weapons (similarity 0.83)
• Natural selection usually favors modest weapon size because cost offsets benefit (similarity 0.82)
• An inexpensive weapon made elaborate armor a deadly liability rather than protection. (similarity 0.82)
• Comparisons of animal and human weapons have a long scholarly tradition. (similarity 0.82)
• Balanced selection keeps most animal weapons modest rather than extreme. (similarity 0.81)
• Weapon size in animal species is under stabilizing selection, not open-ended directional selection (similarity 0.81)
• Weapon evolution needs both competition and economically defensible resources (similarity 0.81)
• Weapons grow late because development prioritizes mandatory survival expenses first (similarity 0.81)
• Arms-race weapon growth makes resource trade-offs drastically impair body functions (similarity 0.81)

Broader Connections

• Weapons evolve only when reproductive benefits exceed costs #corroborates (0.82) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 199
• Economic logic explains weapon evolution across virtually all animal species #corroborates (0.78) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 198
• Competition for reproduction drives evolution of nature’s biggest weapons #corroborates (0.75) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136
• Human armies and social insects solved the same weapon trade-off by role specialization #expands (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 133