Shine Richard
Zoology Department, University of New England, 2351, Armidale, N.S.W., Australia.
Oecologia. 1978 Jan;33(3):269-277. doi: 10.1007/BF00348113.
This paper reviews published literature on snakes to test the hypothesis that large male size, relative to female size, evolves because of the advantage it confers in male combat. Analysis of the data reveals a high correlation between the occurrence of male combat, and sexual dimorphism in which the male is the larger sex. This correlation holds (i) within the total sample of snake species (n=224), (ii) within the family Colubridae (n=134), and (iii) in a comparison between the eight families of snakes for which data are available. These results strongly support the hypothesis that large male size is an adaptation to intrasexual competition. The analysis also shows that females are larger than males in about 66% of snake species, that male combat is known in only about 15% of species, and that both sexual size dimorphism and the incidence of male combat tend to be distributed along taxonomic lines.
本文回顾了已发表的关于蛇类的文献，以检验这样一个假设：相对于雌性体型而言，雄性体型较大是因为其在雄性争斗中具有优势而进化而来的。对数据的分析揭示了雄性争斗的发生与两性异形（其中雄性为较大性别的情况）之间存在高度相关性。这种相关性在以下情况中均成立：（i）在蛇类物种的总样本中（n = 224）；（ii）在游蛇科中（n = 134）；以及（iii）在有数据可用的八个蛇类科之间的比较中。这些结果有力地支持了这样一个假设，即雄性体型较大是对种内竞争的一种适应。分析还表明，在约66%的蛇类物种中雌性比雄性大，已知只有约15%的物种存在雄性争斗，并且两性体型差异和雄性争斗的发生率都倾向于沿着分类学界限分布。
