Wiens John J, Reeder Tod W, Oca Adrián Nieto Montes De
Section of Amphibians and Reptiles, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, 15213-4080.
Department of Biology, San Diego State University, San Diego, California, 92182-4614.
Evolution. 1999 Dec;53(6):1884-1897. doi: 10.1111/j.1558-5646.1999.tb04570.x.
Understanding evolution of geographic variation in sexually dimorphic traits is critical for understanding the role that sexual selection may play in speciation. We performed a phylogenetic analysis of geographic variation in sexual dichromatism in the Yarrow's spiny lizard (Sceloporus jarrovii), a taxon that exhibits remarkable diversity in male coloration among populations (e.g., black, red, green, yellow, blue, brown). An mtDNA phylogeny based on approximately 880 bp from the 12S ribosomal RNA gene and 890 bp from the ND4 gene was reconstructed for 30 populations of S. jarrovii and eight other species of the torquatus species group using maximum-likelihood and parsimony methods. The phylogeny suggests that S. jarrovii consists of at least five evolutionary species, none of which are sister taxa. Although intraspecific diversity in male coloration is less than indicated by previous taxonomy, two species formerly referred to as S. jarrovii exhibit impressive geographic variation in sexual dichromatism. In one of these species, the phylogeny shows the independent evolution of a distinctive blue color morph in different parts of the species range. This pattern suggests that sexual selection may lead to striking phenotypic divergence among conspecific populations and striking convergence. Results also demonstrate the importance of a phylogenetic perspective in studies of evolutionary processes within nominal species and the problematic nature of "polytypic" species recognized under the biological species concept.
了解两性异形性状的地理变异进化对于理解性选择在物种形成中可能发挥的作用至关重要。我们对雅罗刺蜥（Sceloporus jarrovii）的性二态性地理变异进行了系统发育分析，该分类群在种群间雄性体色表现出显著的多样性（例如黑色、红色、绿色、黄色、蓝色、棕色）。基于来自12S核糖体RNA基因的约880bp和来自ND4基因的890bp构建了一个线粒体DNA系统发育树，使用最大似然法和简约法对30个雅罗刺蜥种群以及torquatus物种组的其他8个物种进行了分析。该系统发育树表明雅罗刺蜥至少由五个进化物种组成，其中没有一个是姐妹分类单元。尽管雄性体色的种内多样性低于先前分类学所表明的，但两个以前被称为雅罗刺蜥的物种在性二态性方面表现出令人印象深刻的地理变异。在其中一个物种中，系统发育树显示在该物种分布范围的不同区域，一种独特的蓝色形态独立进化。这种模式表明性选择可能导致同种种群之间出现显著的表型分化和显著的趋同。结果还证明了系统发育观点在名义物种内进化过程研究中的重要性，以及在生物物种概念下被认可的“多型”物种的问题本质。
