The evolution of sexual size dimorphism in cottontail rabbits (Sylvilagus, Leporidae)
The evolution of sexual size dimorphism in cottontail rabbits (Sylvilagus, Leporidae)
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DOI：
10.1111/j.1095-8312.2008.01035.x
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发表时间：
2008-09-01
影响因子：
1.9
通讯作者：
Roth, V. Louise
中科院分区：
文献类型：
--
作者：
Davis, Candace M.;Roth, V. Louise
在哺乳动物中，“女性偏见”的性别大小二态性（SSD），其中女性比男性大，是罕见的。在本研究中，我们研究了Sylvilagus，一个所谓的情况下，女性偏向SSD，SSD，身体大小和生活史变量之间的物种之间的进化相关性。我们发现：（1）尽管大多数物种是雌性偏好的，但SSD的程度和方向的变化比以前认识到的要大;（2）SSD的程度随着体型的增大而减小。因此，Sylvilagus提供了一个新的例子，不寻常的女性偏见的分类群，其中SSD的异速生长是一致的“Rensch规则”。作为一个推论Rensch的规则，我们观察到，SSD在Sylvilagus的变化通常与更大，更显着的变化，男性比女性。女性偏向SSD可以通过选择较大的女性，较小的男性，或两者兼而有之。虽然较大的女性尺寸可能与高繁殖力和非常快速的胎儿和新生儿的生长在Sylvilagus，我们发现很少的证据SSD和各种繁殖力相关的性状之间的相关性在物种比较。较小的男性尺寸可能会通过更大的流动性和减少能量需求而获得更大的生殖成功。我们建议，一套特征（女性分散，大的男性家庭范围，减少侵略，和滥交的交配系统）有利于较小的男性，从而影响了SSD在棉尾的演变。(C)2008年，伦敦林奈学会。
In mammals, 'female-biased' sexual size dimorphism (SSD), in which females are larger than males, is uncommon. In the present study, we examined Sylvilagus, a purported case of female-biased SSD, for evolutionary correlations among species between SSD, body-size, and life-history variables. We find that: (1) although most species are female-biased, the degree and direction of SSD vary more than was previously recognized and (2) the degree of SSD decreases with increasing body size. Hence, Sylvilagus provides a new example, unusual for a female-biased taxon, in which allometry for SSD is consistent with 'Rensch's Rule'. As a corollary to Rensch's Rule, we observe that changes in SSD in Sylvilagus are typically associated with larger, more significant changes in males than females. Female-biased SSD could be produced by selection for larger females, smaller males, or both. Although larger female size may be related to high fecundity and the extremely rapid fetal and neonatal growth in Sylvilagus, we find little evidence for a correlation between SSD and various fecundity-related traits in among-species comparisons. Smaller male size may confer greater reproductive success through greater mobility and reduced energetic requirements. We propose that a suite of traits (female dispersion, large male home ranges, reduced aggression, and a promiscuous mating system) has favoured smaller males and thus influenced the evolution of SSD in cottontails. (C) 2008 The Linnean Society of London.