雪山石龙子蜥蜴（Niveoscincus microlepidotus）的兼性性别分配

Facultative sex allocation in snow skink lizards (Niveoscincus microlepidotus).

作者信息

Olsson M, Shine R

机构信息

School of Biological Sciences, The University of Sydney, Zoology Building AO8, NSW 2006, AustraliaDepartment of Zoology, The University of Gothenburg, Medicinaregatan, Gothenburg, Sweden.

出版信息

J Evol Biol. 2001 Jan 8;14(1):120-128. doi: 10.1046/j.1420-9101.2001.00255.x.

DOI:10.1046/j.1420-9101.2001.00255.x

PMID:29280586

Abstract

Mathematical models suggest that reproducing females may benefit by facultatively adjusting their relative investment into sons vs. daughters, in response to population-wide shifts in operational sex ratio (OSR). Our field studies on viviparous alpine skinks (Niveoscincus microlepidotus) document such a case, whereby among- and within-year shifts in OSR were followed by shifts in sex allocation. When adult males were relatively scarce, females produced male-biased litters and larger sons than daughters. The reverse was true when adult males were relatively more common. That is, females that were courted and mated by few males produced mainly sons (and these were larger than daughters), whereas females that were courted and mated by many males produced mainly daughters (and these were larger than sons). Maternal body size and condition also covaried with sex allocation, and the shifting pattern of sexual size dimorphism at birth may reflect these correlated effects rather than a discrete component of an evolved sex-allocation strategy.

摘要

数学模型表明，繁殖期雌性可能会通过根据种群范围内的实际性比（OSR）变化来灵活调整对儿子和女儿的相对投资而获益。我们对胎生高山石龙子（Niveoscincus microlepidotus）的野外研究记录了这样一个案例，即年间和年内OSR的变化之后伴随着性别分配的变化。当成年雄性相对稀少时，雌性产出雄性偏多的窝仔，且儿子比女儿体型大。当成年雄性相对更常见时，情况则相反。也就是说，被少数雄性求偶并交配的雌性主要生儿子（且这些儿子比女儿体型大），而被许多雄性求偶并交配的雌性主要生女儿（且这些女儿比儿子体型大）。母体的体型和状况也与性别分配相关，出生时性大小二态性的变化模式可能反映了这些相关效应，而非进化的性别分配策略中的一个离散组成部分。