Weapons in arms races get so big they impair other bodily functions

Evidence

As weapons get big they also get expensive, and males with the longest horns now had stunted eyes. By the end of the experiment, males selected for longer horns had eyes that were 30 percent smaller than males selected for shorter horns. Stunted growth arises because of a limited availability of nutrients. Tissues require energy and materials to grow, and allocating resources to the production of one structure can mean that those same resources are no longer available for the growth of another. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295 (#corroborates, via linked claim)

Resource allocation trade-offs shape the development of all animals, but most of the time the effects are trivial. When animals begin to invest unusually heavily into particular structures, however, the effects of trade-offs become more pronounced. Weapons caught up in arms races get very big very fast, and in these species resources channeled into growth of the weapons can drastically impair bodily functions. In insects, this sometimes means reduced growth of other body parts. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 296 (#corroborates, via linked claim)

The ability to uncouple development paved the way for independent evolution of carnivore teeth—canines diverged from premolars, and premolars from molars. In social insects, an analogous uncoupling permitted soldiers and workers to evolve independently, and to diverge considerably in form. Soldiers didn’t need to run efficiently, fly, conduct colony maintenance tasks, or even reproduce. They had only to perform as soldiers. Their release from these other tasks meant that the negative consequences of enlarged weapon sizes were minimal. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 128 (#qualifies, via linked claim)

Categorization

• XREF: connects to: Arms-race weapon growth makes resource trade-offs drastically impair body functions — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 296; Growing large weapons diverts resources and stunts other body parts — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295; Weapon growth is far more resource-sensitive than other body parts — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 340 (+10 more)

Related

• Growing large weapons diverts resources and stunts other body parts (similarity 0.94)
• Arms-race weapon growth makes resource trade-offs drastically impair body functions (similarity 0.94)
• Releasing soldiers from other tasks lets weapons evolve to extremes (similarity 0.90)
• Weapon growth is far more resource-sensitive than other body parts (similarity 0.88)
• Weapon size should track resource availability more than any mandatory body part (similarity 0.87)
• Infections shrink weapon growth because immunity consumes the same resource pool (similarity 0.87)
• Animal weapons evolved to extremes far beyond practical size (similarity 0.86)
• Weapons grow late because development prioritizes mandatory survival expenses first (similarity 0.86)
• Species with huge weapons often show weak current selection on them. (similarity 0.84)
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races (similarity 0.84)
• Human armies and social insects solved the same weapon trade-off by role specialization (similarity 0.84)
• Early survival advantages compound into huge adult differences in weapon resources (similarity 0.84)
• Balanced selection keeps most animal weapons modest rather than extreme. (similarity 0.84)
• Predator weapons stay small because larger ones hinder hunting (similarity 0.84)
• Animal weapons can evolve rapidly within just seven generations (similarity 0.84)

Broader Connections

• Growing large weapons diverts resources and stunts other body parts #corroborates (0.95) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 295
• Arms-race weapon growth makes resource trade-offs drastically impair body functions #corroborates (0.90) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 296
• Releasing soldiers from other tasks lets weapons evolve to extremes #qualifies (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 128
• Weapon growth is far more resource-sensitive than other body parts #complicates (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 340
• Animal weapons evolved to extremes far beyond practical size #expands (0.50) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 2