Diet alters male horn allometry in the beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)
Diet alters male horn allometry in the beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)
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DOI：
10.1098/rspb.1997.0081
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发表时间：
1997-04-22
影响因子：
4.7
通讯作者：
Emlen, DJ
中科院分区：
文献类型：
--
作者：
Emlen, DJ
达尔文认为雄性甲虫的角是性选择最引人注目的例子之一。与鹿或麋鹿的鹿角一样，甲虫的角与雄性的体型成正比，因此体型较大的雄性甲虫的角比体型较小的雄性甲虫的角长得不成比例。人们通常认为这种标度关系（“静态异速生长”）对环境的短期变化不敏感，因此它们经常被用作种群或物种的诊断属性。在这里，我报告了角甲虫的繁殖实验，这些实验表明，当幼虫营养发生变化时，雄性角长度和体型之间的比例关系会发生变化。在任何给定的体型下，以低质量饮食饲养的雄性的角长度都比以高质量饮食饲养的雄性兄弟姐妹更长。这种“异速生长可塑性”可以解释在自然群体中观察到的相同尺度关系中观察到的季节变化。这些实验表明，性选择特征的缩放关系可以对环境的变化做出兼性反应，从而揭示了男性调节夸大的第二性特征产生的新机制。
Darwin considered the horns of male beetles to be among the most striking examples of sexual selection. As with antlers in deer or elk, beetle horns scale positively with male body size, with the result that large males have disproportionately longer horns than small males. It is generally assumed that such scaling relationships ('static allometries') are insensitive to short-term changes in the environment, and for this reason they are regularly used as diagnostic attributes of populations or species. Here I report breeding experiments on horned beetles that demonstrate that the scaling relationship between male horn length and body size changes when larval nutrition changes. Males reared on a low-quality diet had longer horn lengths at any given body size than sibling males reared on a high-quality diet. Such 'allometry plasticity' may explain seasonal changes observed in this same scaling relationship in a natural population. These experiments demonstrate that scaling relationships of sexually selected traits can respond facultatively to variation in the environment, thereby revealing a new mechanism by which males regulate the production of exaggerated secondary sexual traits.