The Evolution of Animal Weapons

@article{Emlen2008TheEO,
  title={The Evolution of Animal Weapons},
  author={Douglas J. Emlen},
  journal={Annual Review of Ecology, Evolution, and Systematics},
  year={2008},
  volume={39},
  pages={387-413}
}
  • D. Emlen
  • Published 31 October 2008
  • Biology
  • Annual Review of Ecology, Evolution, and Systematics
Males in many species invest substantially in structures that are used in combat with rivals over access to females. These weapons can attain extreme proportions and have diversified in form repeatedly. I review empirical literature on the function and evolution of sexually selected weapons to clarify important unanswered questions for future research. Despite their many shapes and sizes, and the multitude of habitats within which they function, animal weapons share many properties: They evolve… 
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525 Citations
Highly Influential Citations
38
Background Citations
246
Methods Citations
8
Results Citations
6

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525 Citations

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Investigation of the impact of natural dietary variation on weapon structural integrity in a fighting insect, Narnia femorata, finds a striking effect of cactus fruit phenology on weapons and hints that the size of the weapons may be a poor signal of weapon performance when nutrition is variable.
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    Biological reviews of the Cambridge Philosophical Society
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It is conceptualized that there are five ways in which a sexually dimorphic trait, apart from the primary sex traits, can be fixed: sexual selection, fecundity selection, parental role division, differential niche occupation between the sexes, and interference competition.
The hidden links between animal weapons, fighting style and their expression on contest resolution
In many species that fight over resources, individuals use specialized structures to overpower their rivals (i.e. weapons). Despite their similar roles for contest settlement (i.e. affecting the…
Why Sexually Selected Weapons Are Not Ornaments.
Males missing their sexually selected weapon have decreased fighting ability and mating success in a competitive environment
TLDR
It is found that weapon loss decreased both fighting ability and mating success in the leaf-footed cactus bug Narnia femorata Stål, and the observed difference in mating success was not due to female rejection, but instead was likely due to competitive male interactions.
Opinion Why Sexually Selected Weapons Are Not Ornaments
TLDR
How male–male competition and female choice are distinct mechanisms of sexual selection, and why weapons and ornaments are fundamentally different types of traits are outlined.
Digest: Sexually selected weapons: Winning the fight, but losing the war for reproduction on a changing battlefield *
  • V. Narayan
  • Biology
    Evolution; international journal of organic evolution
  • 2020
TLDR
In the Japanese rhinoceros beetle, Trypoxylus dichotomus, del Sol et al. found that selection favors large horns in populations where males compete over guardianship of scarce female feeding territories, however, in other populations, an abundance ofFemale feeding territories reduces the chance of mating success for these guarding males, leading to the evolution of relatively shorter horn sizes.
It takes two to tango : functional roles , sexual selection and allometry of multiple male weapons in the flower beetle
TLDR
The findings suggest that sexual selection acts on both male weapon traits in D. w.
The importance of animal weapons and fighting style in animal contests
TLDR
A meta-analysis spanning 1,138 studies is developed to identify what aspects of animal weapons are measured in the literature, and how these measures bias knowledge, and to find that the importance of weapon size differs depending on the fighting style.
A weapons–testes trade-off in males is amplified in female traits
TLDR
It is reported that a documented trade-off in investment between hind-limb weapons and testes in leaf-footed cactus bugs, Narnia femorata, is even more pronounced in female hind limbs and ovaries, suggesting future studies of reproductive trade-offs should consider factors such as tissue expense and developmental timing.
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