The aridification of Africa resulted in the fragmentation of forests and the expansion of an arid corridor stretching from the northeast to southwest portion of sub-Saharan Africa, but the role this corridor has had in species-level diversification of southern African vertebrates is poorly understood. The skink species Mochlus afer and M. sundevallii inhabit wide areas of the arid corridor and are therefore an ideal species pair for studying patterns of genetic and phenotypic diversity associated with this landscape. However, species boundaries between these taxa have been controversial. Using multi-locus molecular and morphological datasets, we investigate diversification patterns of the M. afer-sundevallii Species Complex across the arid corridor. Although analyses of genetic data reveals some genetic structure among geographic populations, results of phylogenetic and morphological analyses provide little support for two distinct evolutionary lineages, suggesting that populations previously referred to as M. afer and M. sundevallii represent a single species, Mochlus sundevallii. Genetic diversity is unequally distributed across the arid corridor, with observed patterns consistent with aridification-facilitated diversification southward across southern Africa. Additional geographic and population-level sampling is necessary before more conclusive inferences can be drawn about the role historical climate transitions have played in skink diversification patterns across southern Africa.

非洲的干旱化导致森林碎片化，干旱的走廊从撒哈拉以南非洲的东北向西南延伸，但人们对该走廊在南部非洲脊椎动物物种层面的多样化中所起的作用知之甚少。枯草物种Mochlus afer和M. sundevallii居住在干旱走廊的广阔区域，因此是研究与该景观相关的遗传和表型多样性模式的理想物种对。但是，这些分类单元之间的物种边界一直存在争议。使用多位点分子和形态数据集，我们调查了M. afer - sundevallii的多样化模式穿过干旱走廊的物种复杂。尽管对遗传数据的分析揭示了地理种群之间的某些遗传结构，但系统发育和形态学分析的结果几乎没有为两个不同的进化谱系提供支持，这表明以前称为M. afer和M. sundevallii的种群仅代表一个物种，即Mochlus sundevallii。。遗传多样性在整个干旱走廊中分布不均，其观察到的模式与南部非洲南部由干旱促进的多样化相一致。在得出关于历史气候变化在整个南部非洲的石龙子化多样化模式中所起的作用的结论性推论之前，有必要进行额外的地理和人口抽样。