Godfrey L R, Samonds K E, Jungers W L, Sutherland M R, Irwin M T
Department of Anthropology, University of Massachusetts at Amherst, Amherst, Massachusetts 01003-9278, USA.
Am J Phys Anthropol. 2004 Mar;123(3):250-76. doi: 10.1002/ajpa.10315.
There is a well-documented relationship between development and other life-history parameters among anthropoid primates. Smaller-bodied anthropoids tend to mature more rapidly than do larger-bodied species. Among anthropoids of similar body sizes, folivorous species tend to grow and mature more quickly than do frugivorous species, thus attaining adult body size at an earlier age. This pattern conforms to the expectations of Janson and van Schaik's "ecological risk aversion hypothesis," which predicts that rates of growth and maturation should vary in inverse relation to the intensity of intraspecific feeding competition. According to the ecological risk aversion hypothesis (RAH), species experiencing high intraspecific feeding competition will grow and mature slowly to reduce the risk of mortality due to food shortages. Species experiencing low levels of intraspecific feeding competition will shorten the juvenile period to reduce the overall duration of this high-risk portion of the life cycle. This paper focuses on development and maturation in lemurs. We show that folivorous lemurs (such as indriids) grow and mature more slowly than like-sized frugivorous lemurs (e.g., most lemurids), but tend to exhibit faster dental development. Their dental developmental schedules are accelerated on an absolute scale, relative to craniofacial growth, and relative to particular life-history landmarks, such as weaning. Dental development has a strong phylogenetic component: even those lemurids that consume substantial amounts of foliage have slower dental development than those indriids that consume substantial amounts of fruit. Implications of these results for the RAH are discussed, and an explanation for this hypothesis' failure to predict lemur growth schedules is offered. We propose that the differing developmental schedules of folivorous and frugivorous lemurs may reflect different solutions to the ecological problem of environmental instability: some rely on a strategy of low maternal input and slow returns, while others rely on a strategy of high maternal input and fast returns.
在类人猿灵长类动物中，发育与其他生活史参数之间存在充分记录的关系。体型较小的类人猿往往比体型较大的物种成熟得更快。在体型相似的类人猿中，食叶物种往往比食果物种生长和成熟得更快，因此在更早的年龄达到成年体型。这种模式符合詹森和范·谢克的“生态风险规避假说”的预期，该假说预测生长和成熟速率应与种内觅食竞争强度呈反比关系。根据生态风险规避假说（RAH），经历高强度种内觅食竞争的物种将生长和成熟缓慢，以降低因食物短缺导致死亡的风险。经历低水平种内觅食竞争的物种将缩短幼年期，以减少生命周期中这一高风险部分的总体持续时间。本文重点关注狐猴的发育和成熟。我们表明，食叶狐猴（如大狐猴科）比体型相似的食果狐猴（如大多数狐猴科）生长和成熟得更慢，但往往表现出更快的牙齿发育。相对于颅面生长以及相对于特定的生活史标志（如断奶），它们的牙齿发育时间表在绝对尺度上加快。牙齿发育有很强的系统发育成分：即使是那些消耗大量树叶的狐猴科，其牙齿发育也比那些消耗大量果实的大狐猴科慢。讨论了这些结果对RAH的影响，并为该假说未能预测狐猴生长时间表提供了解释。我们提出，食叶狐猴和食果狐猴不同的发育时间表可能反映了对环境不稳定这一生态问题的不同解决方案：一些依赖低母体投入和缓慢回报的策略，而另一些则依赖高母体投入和快速回报的策略。
