Towards an Integrative Understanding of Animal Weapons

Supervisor: Professor Christine Miller 

Across the earth, animals engage in conflict that comes in a dizzying variety of forms. Agonistic encounters may involve electrical fields, shock waves, venoms, high heat, and lethal blows. Mechanical weapons include the antlers of deer, the horns of beetles, and the claws of fiddler crabs. Animal weapons can be varied in their manner of expression, and they display extraordinary diversity even within closely related groups. This MPhil project will be focused on one of the two following areas of high importance in this field:

1. The Multifunctionality of Weapons. Weapons have often been discussed as having one function, though many weapons are used in numerous ways. Functions of a single weapon may include, for example, defence, foraging, signalling, same-sex physical contests, mate choice, and more. We will not fully understand the evolution of weapon diversity unless we investigate the myriads of selective factors acting on weapons and how these vary across time and space.

2. The Role of Skill in Contest Success. Some individuals will direct and wield weapons more effectively than others. Not all animals within a single population fight, defend, and hunt in the same way. An emerging question is the degree to which skill plays a role in contest success. This research will capitalize upon the extraordinary opportunities provided by the family of leaf-footed bugs (Hemiptera:Coreidae). Many insects in this family have enlarged and spiny hind-leg weapons that they use to fight over territories on host plants. 

Type of work 

The student will work together with the supervisor to identify a suitable project that can be accomplished within the time period. Then, the student will work together with the entire Biotic Interactions Group to plan the project design. The student will then independently conduct the experiments. Other students in the Group will be working on insects and behaviour, providing a rich intellectual environment for the development and completion of the work.

Importance of the area of work concerned

The striking diversity of animal weapons yields outstanding opportunities for scientific investigation. Indeed, such work, while focused on weapons, will likely yield insights that can help us understand the spectacular diversity in animal forms more generally.

References

Briffa, M., & Lane, S. M. (2017). The role of skill in animal contests: a neglected component of fighting ability.

Proceedings of the Royal Society B: Biological Sciences, 284(1863), 20171596. Li Y & Miller CW (2025).

Living with males leads to female physical injury in the leaf-footed cactus bug. Behavioral Ecology. https://doi.org/10.1093/beheco/araf068 Miller CW, Kimball RT & Forthman M (2024).

The evolution of multi-component weapons in the superfamily of leaf-footed bugs. Evolution 78: 635–651 Metz, M.C. et al. (2018)

Predation shapes the evolutionary traits of cervid weapons. Nature ecology & evolution 2, 1619-1625