Plavcan J Michael, Ruff Christopher B
Department of Anthropology, University of Arkansas, Fayetteville, AR 72701, USA.
Am J Phys Anthropol. 2008 May;136(1):65-84. doi: 10.1002/ajpa.20779.
Anthropoid primates are well known for their highly sexually dimorphic canine teeth, with males possessing canines that are up to 400% taller than those of females. Primate canine dimorphism has been extensively documented, with a consensus that large male primate canines serve as weapons for intrasexual competition, and some evidence that large female canines in some species may likewise function as weapons. However, apart from speculation that very tall male canines may be relatively weak and that seed predators have strong canines, the functional significance of primate canine shape has not been explored. Because carnivore canine shape and size are associated with killing style, this group provides a useful comparative baseline for primates. We evaluate primate maxillary canine tooth size, shape and relative bending strength against body size, skull size, and behavioral and demographic measures of male competition and sexual selection, and compare them to those of carnivores. We demonstrate that, relative to skull length and body mass, primate male canines are on average as large as or larger than those of similar sized carnivores. The range of primate female canine sizes embraces that of carnivores. Male and female primate canines are generally as strong as or stronger than those of carnivores. Although we find that seed-eating primates have relatively strong canines, we find no clear relationship between male primate canine strength and demographic or behavioral estimates of male competition or sexual selection, in spite of a strong relationship between these measures and canine crown height. This suggests either that most primate canines are selected to be very strong regardless of variation in behavior, or that primate canine shape is inherently strong enough to accommodate changes in crown height without compromising canine function.
类人灵长类动物以其高度两性异形的犬齿而闻名，雄性的犬齿比雌性的高出多达400%。灵长类动物的犬齿两性异形已有大量记录，人们普遍认为，大型雄性灵长类动物的犬齿是种内竞争的武器，并且有证据表明，某些物种中大型雌性犬齿可能同样具有武器功能。然而，除了猜测非常高大的雄性犬齿可能相对较弱以及种子捕食者有强壮的犬齿外，灵长类动物犬齿形状的功能意义尚未得到探索。由于食肉动物的犬齿形状和大小与捕杀方式相关，这一群体为灵长类动物提供了一个有用的比较基线。我们根据体型、头骨大小以及雄性竞争和性选择的行为和人口统计学指标，评估灵长类动物上颌犬齿的大小、形状和相对抗弯强度，并将它们与食肉动物的进行比较。我们证明，相对于头骨长度和体重，灵长类雄性犬齿平均与体型相似的食肉动物的犬齿一样大或更大。灵长类雌性犬齿的大小范围涵盖了食肉动物的。灵长类雄性和雌性犬齿通常与食肉动物的一样强壮或更强壮。尽管我们发现食种子的灵长类动物有相对强壮的犬齿，但我们发现灵长类雄性犬齿强度与雄性竞争或性选择的人口统计学或行为估计之间没有明确的关系，尽管这些指标与犬齿冠高之间存在很强的关系。这表明，要么大多数灵长类动物的犬齿无论行为差异如何都被选择为非常强壮，要么灵长类动物的犬齿形状本身就足够强壮，能够适应冠高的变化而不影响犬齿功能。
