Antler
Antlers are a single structure composed of bone, cartilage, fibrous tissue, skin, nerves, and blood vessels.
[2] Antler comes from the Old French antoillier (see present French : "Andouiller", from ant-, meaning before, oeil, meaning eye and -ier, a suffix indicating an action or state of being)[3][4] possibly from some form of an unattested Latin word *anteocularis, "before the eye"[5] (and applied to the word for "branch" or "horn"[4]).
A horn's interior of bone is covered by an exterior sheath made of keratin[7] (the same material as human fingernails and toenails).
Nevertheless, fertile does from other species of deer have the capacity to produce antlers on occasion, usually due to increased testosterone levels.
[6] Antlers are considered one of the most exaggerated cases of male secondary sexual traits in the animal kingdom,[10] and grow faster than any other mammal bone.
[citation needed] A 2019 study published in Science identified eight genes active in antler formation that are normally associated with bone cancer, particularly osteosarcoma.
This was taken to indicate that antler formation is more similar to a highly controlled form of cancer growth than to normal bone development.
[13] Bones typically serve a structural purpose, with load bearing abilities that are greater than any other part of an animal's body.
[18] In antlers, the mineral content is considerably lower than other examples of bone tissue, while having a high volume of collagen.
[19] This leads antlers to having lower yield strength and stiffness, but higher fracture toughness when compared to human cortical bone.
Bovine femurs must withstand greater stresses, holding up the body of the animal, whereas an antler is used for sexual selection and competition.
The principal means of evolution of antlers is sexual selection, which operates via two mechanisms: male-to-male competition (behaviorally, physiologically) and female mate choice.
[10] Males with the largest antlers are more likely to obtain mates and achieve the highest fertilization success due to their competitiveness, dominance and high phenotypic quality.
[22] There is evidence to support that antler size influences mate selection in the red deer, and has a heritable component.
If antlers functioned only in male–male competition for mates, the best evolutionary strategy would be to shed them immediately after the rutting season, both to free the male from a heavy encumbrance and to give him more time to regrow a larger new pair.
Reindeer (Rangifer tarandus) are the only cervid species that inhabit the Arctic and subarctic regions of the globe, yet their most striking distinction is the presence of pedicles after birth and antlers in both males and females.
[26][27] One possible reason that females of this species evolved antlers is to clear away snow so they can eat the vegetation underneath.
[30] In other species of deer, the presence of antlers in females indicates some degree of intersex condition, the frequency of which has been seen to vary from 1.5%[31] to 0.02%.
[34] The diversification of antlers, body size and tusks has been strongly influenced by changes in habitat and behavior (fighting and mating).
[35] The earliest fossil remains of antlers that have been found are dated to the early Miocene, about 17 million years ago.
The study revealed that three-pointed structures of Capreolinae and Cervini are homoplasious, and their subclades gained synapomorphous tines.
Discarded antlers represent a source of calcium, phosphorus and other minerals and are often gnawed upon by small animals, including squirrels, porcupines, rabbits and mice.
The first organization to keep records of sizes was Rowland Ward Ltd., a London taxidermy firm, in the early 20th century.
[43] Hunters have developed terms for antler parts: beam, palm, brow, bez or bay, trez or tray, royal, and surroyal.
In Yorkshire in the United Kingdom roe deer hunting is especially popular due to the large antlers produced there.
[40] In the United States in 2017 sheds fetch around US$10 per pound, with larger specimens in good condition attracting higher prices.
[49] It was an especially important material in the European Late Paleolithic, used by the Magdalenian culture to make carvings and engraved designs on objects such as the so-called Bâton de commandements and the Bison Licking Insect Bite.
In later periods, antler—used as a cheap substitute for ivory—was a material especially associated with equipment for hunting, such as saddles and horse harness, guns and daggers, powder flasks, as well as buttons and the like.
[55][56] Elk, deer, and moose antlers have also become popular forms of dog chews that owners purchase for their pet canines.
