Animal weapon
[1] Many hypotheses have been produced by researchers to possibly explain the mechanisms behind the evolution of weapons, with studies detailing the intensity, duration, and conclusion of intraspecific combat, as well as analyzing the rapid diversification within species.
[5] Since Darwin's publication The Descent of Man, extensive research has been done on the presence of agonistic behavior and the usage of animal weaponry by different species.
[1] Weaponry displays in animals have been found to increase their likelihood of survival in different ways, such as when interacting with other individuals or trying to find another mate, or to defend against predators.
[5] Antlers, complex and unique weapons that are an extension of an animal's skull, are found among male deers, as well as female reindeers, ungulates who are even-toed ruminants.
[6] Horns, permanent pointed projections consisting of a covering of keratin and other proteins surrounding a core of live bone, are found commonly among bovids, as well as the pronghorns, which are ruminant artiodactyls.
Apart from mammals, the only other group of land vertebrates that shows widespread adoption of weapons are the chameleons, who possess horn-like structures for fighting over access to mates.
[13] Harlequin beetles have legs that are longer than their entire body, using which they protect a suitable spot for a female to lay eggs.
[14] Camel crickets use spines on their tibias for two reasons; (1) to fight other males for access to females, and (2) to pin mates as a form of coercion.
[5] One hypothesized mechanism for this is the gradual change in weaponry function from purely physical agonistic behavior, to a stronger emphasis on display, resulting in potentially more elaborate weapons.
Sites that have localized, defendable resources, like a single food or water source, or a breeding burrow, often are where species with weapons are found.
[5] Sexual selection has been a main focus on weaponry and antagonist interactions between animals, with males that present the largest weapons having the highest probability of winning.
[18] Sexual selection has been credited by previous researchers as the main influence of nature's extravagant weaponry for the purpose of attractive females.
[5] During agonistic interactions, there is the potential risk of weaponry lost resulting in a possible decrease in an individual's fighting ability and overall fitness.
[5] The display of weaponry has been found to be favored in animals that frequently engage in contest as a mechanism to decrease the costs of aggression.
