Lifetime selection on a hypoallometric size trait in the spotted hyena
Lifetime selection on a hypoallometric size trait in the spotted hyena
复制标题
斑鬣狗低异速尺寸性状的终生选择
DOI：
10.1098/rspb.2010.2512
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
K. Holekamp
中科院分区：
文献类型：
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作者：
Eli M. Swanson;I. Dworkin;K. Holekamp
体型相关的特征是自然选择的常见目标，然而，关于哺乳动物选择的数据相对缺乏，特别是来自测量终身繁殖成功率（LRS）的研究。本文首次利用LRS对大型陆生食肉动物斑点鬣狗的体型相关性状进行了表型选择分析，发现斑点鬣狗表现出罕见的雌性偏性体型二态性（SSD）。利用通径分析，我们研究了选择的操作，以解决解释斑点鬣狗SSD的假设。理想的尺寸测量是难以捉摸的，异速变化经常混淆尺寸代理的解释。我们采用了一种新颖的方法，整合了两种常见的评估体型的方法，并证明了体型相关性状的终生选择与整体体型的低异速比例。我们的数据支持对鬣狗低异速性状的选择，但不支持对表现出等速或高异速缩放关系的性状的选择，也不支持对常用的全身尺寸的选择。我们的研究结果代表了大型食肉动物一生选择的首次估计，并提出了斑点鬣狗维持雌性偏向SSD的可能途径。最后，我们的研究结果强调了在估计动物体型时选择合适的测量方法的重要性，并建议在将体型相关性状的选择解释为体型本身的选择时要谨慎。
Size-related traits are common targets of natural selection, yet there is a relative paucity of data on selection among mammals, particularly from studies measuring lifetime reproductive success (LRS). We present the first phenotypic selection analysis using LRS on size-related traits in a large terrestrial carnivore, the spotted hyena, which displays a rare pattern of female-biased sexual size dimorphism (SSD). Using path analysis, we investigate the operation of selection to address hypotheses proposed to explain SSD in spotted hyenas. Ideal size measures are elusive, and allometric variation often obfuscates interpretation of size proxies. We adopt a novel approach integrating two common methods of assessing size, and demonstrate lifetime selection on size-related traits that scale hypoallometrically with overall body size. Our data support selection on hypoallometric traits in hyenas, but not on traits exhibiting isometric or hyperallometric scaling relationships, or on commonly used measures of overall body size. Our results represent the first estimate of lifetime selection on a large carnivore, and suggest a possible route for maintenance of female-biased SSD in spotted hyenas. Finally, our results highlight the importance of choosing appropriate measures when estimating animal body size, and suggest caution in interpreting selection on size-related traits as selection on size itself.