Wallace's Line demarcates a biogeographical boundary between the Indomalaya and Australasian ecoregions. Most placental mammalian genera, for example, occur to the west of this line, whereas most marsupial genera occur to the east. However, macaque monkeys are unusual because they naturally occur on both western and eastern sides. To further explore this anomalous distribution, we analyzed 222 mitochondrial genomes from ∼20 macaque species, including new genomes from 60 specimens. These comprise a population sampling of most Sulawesi macaques, Macaca fascicularis (long-tailed macaques) specimens that were collected by Alfred R. Wallace and specimens that were recovered during archaeological excavations at Liang Bua, a cave on the Indonesian island of Flores. In M. fascicularis, three mitochondrial lineages span the southernmost portion of Wallace's Line between Bali and Lombok, and divergences within these lineages are contemporaneous with, and possibly mediated by, past dispersals of modern human populations. Near the central portion of Wallace's Line between Borneo and Sulawesi, a more ancient dispersal of macaques from mainland Asia to Sulawesi preceded modern human colonization, which was followed by rapid dispersal of matrilines and was subsequently influenced by recent interspecies hybridization. In contrast to previous studies, we find no strong signal of recombination in most macaque mitochondrial genomes. These findings further characterize macaque evolution before and after modern human dispersal throughout Southeast Asia and point to possible effects on biodiversity of ancient human cultural diasporas.

华莱士之线划定了Indomalaya与澳大利亚生态区之间的生物地理边界。例如，大多数胎盘哺乳动物属发生在这条线的西部，而大多数有袋动物属发生在该线的东部。但是，猕猴很不寻常，因为它们自然地出现在西侧和东侧。为了进一步探索这种异常分布，我们分析了来自约20个猕猴物种的222个线粒体基因组，包括来自60个标本的新基因组。这些样本包括大多数苏拉威西猕猴，长尾猕猴（Macaca fascicularis）标本（由Alfred R. Wallace）采集的标本，以及在印度尼西亚佛洛雷斯岛的一个山洞梁布阿（Liang Bua）进行考古发掘时回收的标本。在fas M. fascicularis，三个线粒体谱系跨越了华莱士线在巴厘岛和龙目岛之间的最南端，这些谱系中的分歧与现代人口的过去散布是同时发生的，并且可能是由过去的传播所介导的。在华莱士在婆罗洲和苏拉威西河之间的线的中心部分附近，猕猴从亚洲大陆到苏拉威西河的更古老的扩散是在现代人类殖民之前，随后母体的迅速扩散，随后受到最近种间杂交的影响。与以前的研究相反，我们发现在大多数猕猴线粒体基因组中没有强烈的重组信号。