Markusson Eystein, Folstad Ivar
Department of Ecology/Zoology, IBG, University of Tromsø, 9037 Tromsø, Norway fax: +47 776 45600; e-mail:
Oecologia. 1997 May;110(4):501-507. doi: 10.1007/s004420050186.
Fluctuating asymmetry (FA) in ornamental characters may reflect developmental stability in the translation from genotype to phenotype. Antlers of reindeer show FA, are visually conspicuous ornaments and are important in intraspecific assessment. We show that there is a negative relationship between size and asymmetry in visual antler characteristics (i.e., antler length and number of tines) among free-ranging male reindeer in rut. This indicates that individuals that develop large ornaments are better able to buffer developmental stress than individuals that develop small ornaments. There is no relationship between asymmetry in antler length and asymmetry in jaw length, suggesting that symmetry in antlers does not reflect overall body symmetry. This difference may be caused by trait-specific sensitivity to developmental stress. Such stress may partly be caused by parasites, which show a positive association with asymmetry in antlers, but no relationship to asymmetry in jaws. Our results indicate that antlers may be exposed to directional selection in a visual signaler-receiver system and that information about parasite burden may be obtained from evaluation of asymmetry in antlers developed under exposure to a multitude of environmental stresses.
观赏性特征的波动不对称性（FA）可能反映了从基因型到表型转化过程中的发育稳定性。驯鹿的鹿角表现出FA，是视觉上显著的装饰品，并且在种内评估中很重要。我们发现，在发情期自由放养的雄性驯鹿中，视觉鹿角特征（即鹿角长度和叉枝数量）的大小与不对称性之间存在负相关关系。这表明，发育出大型装饰品的个体比发育出小型装饰品的个体更能缓冲发育压力。鹿角长度的不对称性与颌骨长度的不对称性之间没有关系，这表明鹿角的对称性并不反映整体身体对称性。这种差异可能是由对发育压力的特定性状敏感性引起的。这种压力可能部分是由寄生虫引起的，寄生虫与鹿角的不对称性呈正相关，但与颌骨的不对称性无关。我们的结果表明，在视觉信号发送者-接收者系统中，鹿角可能受到定向选择，并且关于寄生虫负荷的信息可以通过评估在多种环境压力下发育的鹿角的不对称性来获得。
