Shared clade traits like lengthy female investment predispose entire lineages to weapon arms races

Evidence

Sometimes the characteristics inherited by a group of species (species that trace their ancestry back to a shared common ancestor are called a “clade”) cause many members of the clade to all experience similarly strong selection for large weapons. For example, female African elephants invest impressive amounts of time, energy, and nutrition into their offspring during multiyear bouts of pregnancy and nursing. … This means that the crucial backdrop for intense male-male competition in African elephants, a highly skewed ratio of available males to available females, almost certainly existed in all of the other species in this clade, too. It’s probably no coincidence that so many relatives of elephants embarked on paths of rapid and extreme weapon evolution. — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 268

Categorization

• XREF: connects to: Shared inherited traits push entire clades into parallel weapon arms races; Extreme skew in mating success drives arms-race escalation in weaponry; Balancing selection normally curbs weapon size until some lineages escape into runaway arms races — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 22 (+6 more)

Related

• Shared inherited traits push entire clades into parallel weapon arms races (similarity 0.96)
• Identical triggers drive extreme weapon evolution across wildly unrelated clades (similarity 0.87)
• Extreme skew in mating success drives arms-race escalation in weaponry (similarity 0.86)
• Specific conditions are required before weapons escalate into an arms race (similarity 0.85)
• The same three ingredients trigger weapon evolution across wildly divergent animal clades (similarity 0.85)
• Competition for reproduction drives evolution of nature’s biggest weapons (similarity 0.84)
• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races (similarity 0.84)
• Sexual selection drives weapons to extremes because payoffs for winners are enormous. (similarity 0.84)
• Sexual selection can be far stronger than natural selection and drives weapon extremes (similarity 0.83)
• Reproductive success, not survival, drives the largest animal weapons (similarity 0.83)
• Three conditions must align to trigger an animal weapons arms race. (similarity 0.82)
• Specific ecological circumstances must align before weapon arms races begin (similarity 0.82)
• Arms races inevitably stall as weapon costs neutralize reproductive benefits (similarity 0.82)
• Human and animal arms races follow parallel evolutionary dynamics (similarity 0.81)
• Weapon size in animal species is under stabilizing selection, not open-ended directional selection (similarity 0.81)

Broader Connections

• Balancing selection normally curbs weapon size until some lineages escape into runaway arms races #responds-to (0.80) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 22
• The same three ingredients trigger weapon evolution across wildly divergent animal clades #expands (0.70)
• Weapon size is favored when males defend resources females need #corroborates (0.70) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 960
• Males evolve big weapons to defend resources that females visit #expands (0.60)
• Competition for reproduction drives evolution of nature’s biggest weapons #corroborates (0.60) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 136
• Sexual selection can be far stronger than natural selection and drives weapon extremes #qualifies (0.55) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 177
• Symmetrical one-on-one fights are a neglected prerequisite for weapon arms races #corroborates (0.55) — Emlen, Douglas J, Animal Weapons_ The Evolution of Battle, 226