Bonduriansky Russell
School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney NSW 2052, Australia.
Evolution. 2007 Apr;61(4):838-49. doi: 10.1111/j.1558-5646.2007.00081.x.
One of the most pervasive ideas in the sexual selection literature is the belief that sexually selected traits almost universally exhibit positive static allometries (i.e., within a sample of conspecific adults, larger individuals have disproportionally larger traits). In this review, I show that this idea is contradicted by empirical evidence and theory. Although positive allometry is a typical attribute of some sexual traits in certain groups, the preponderance of positively allometric sexual traits in the empirical literature apparently results from a sampling bias reflecting a fascination with unusually exaggerated (bizarre) traits. I review empirical examples from a broad range of taxa illustrating the diversity of allometric patterns exhibited by signal, weapon, clasping and genital traits, as well as nonsexual traits. This evidence suggests that positive allometry may be the exception rather than the rule in sexual traits, that directional sexual selection does not necessarily lead to the evolution of positive allometry and, conversely, that positive allometry is not necessarily a consequence of sexual selection, and that many sexual traits exhibit sex differences in allometric intercept rather than slope. Such diversity in the allometries of secondary sexual traits is to be expected, given that optimal allometry should reflect resource allocation trade-offs, and patterns of sexual and viability selection on both trait size and body size. An unbiased empirical assessment of the relation between sexual selection and allometry is an essential step towards an understanding of this diversity.
性选择文献中最普遍的观点之一是，人们相信性选择的性状几乎普遍呈现正的静态异速生长（即，在同种成年个体样本中，体型较大的个体具有不成比例的较大性状）。在这篇综述中，我表明这一观点与实证证据和理论相矛盾。虽然正异速生长是某些类群中某些性性状的典型特征，但实证文献中正异速生长的性性状占主导地位显然是由于一种抽样偏差，这种偏差反映了对异常夸张（怪异）性状的痴迷。我回顾了来自广泛分类群的实证例子，这些例子说明了信号、武器、抱握和生殖器性状以及非性性状所呈现的异速生长模式的多样性。这些证据表明，正异速生长可能是性性状中的例外而非规律，定向性选择不一定导致正异速生长的进化，反之，正异速生长也不一定是性选择的结果，而且许多性性状在异速生长截距而非斜率上存在性别差异。鉴于最优异速生长应反映资源分配权衡以及性状大小和体型上的性选择和生存选择模式，二次性性状异速生长的这种多样性是可以预期的。对性选择与异速生长之间关系进行无偏差的实证评估是理解这种多样性的关键一步。
