Hall W P
School of Engineering, University of Melbourne, Melbourne, Victoria, Australia.
Cytogenet Genome Res. 2009;127(2-4):143-65. doi: 10.1159/000304050. Epub 2010 Mar 25.
The clade of the North American lizard genus Sceloporus and its relatives comprising the subfamily Phrynosomatinae (Iguanidae) includes perhaps 150 evolutionary lineages. The work reviewed here begins with the discovery of the concentration of Robertsonian chromosomal variability in Sceloporus more than 40 years ago and cytogenetic and genomic evidence of remarkable chromosomal variation within the S. grammicus complex associated with narrow zones of hybridization between different chromosomal races. These discoveries led to hypotheses about hybrid zones involving negative heterosis, possible modes of chromosomal speciation, and the potential roles of such speciation in phylogenesis. The radiation of Sceloporus has now been studied by many different workers extending and mapping the geographic distribution of cytogenetic and genomic variation to understand the biology of the chromosomal variation and to establish the phyletic relationships of the various lineages. The result is a robust phylogeny and a large and still growing database of genic, cytogenetic and other biological parameters. These materials provide a rich series of natural experiments to support both synthetic-comparative and analytical studies of the roles of chromosomal variation, hybrid zones and modes of speciation in phylogenesis and evolutionary success.
北美蜥蜴属斯氏变色蜥及其包含角蜥亚科（鬣蜥科）的近缘物种的进化枝可能包括150个进化谱系。本文所回顾的研究始于40多年前在斯氏变色蜥中发现的罗伯逊染色体变异集中现象，以及在墨西哥斯氏变色蜥复合体中与不同染色体种族间狭窄杂交区域相关的显著染色体变异的细胞遗传学和基因组证据。这些发现引发了关于涉及负杂种优势的杂交区域、染色体物种形成的可能模式以及这种物种形成在系统发生中的潜在作用的假说。现在，许多不同的研究人员对斯氏变色蜥的辐射进行了研究，扩展并绘制了细胞遗传学和基因组变异的地理分布，以了解染色体变异的生物学特性，并确定各个谱系的系统发育关系。结果是形成了一个可靠的系统发育树以及一个庞大且仍在不断增长的关于基因、细胞遗传学和其他生物学参数的数据库。这些材料提供了一系列丰富的自然实验，以支持对染色体变异、杂交区域和物种形成模式在系统发生和进化成功中的作用进行综合比较和分析研究。
