Data from: Speciation over the edge: gene flow among non-human primate species across a formidable biogeographic barrier

Many genera of terrestrial vertebrates diversified exclusively on one or the other side of Wallace's Line, which lies between Borneo and Sulawesi islands in Southeast Asia, and demarcates one of the sharpest biogeographic transition zones in the world. Macaque monkeys are unusual among vertebrate genera in that they are distributed on both sides of Wallace's Line, raising the question of whether dispersal across this barrier was an evolutionary one-off or a more protracted exchange—and if the latter, what were the genomic consequences. To explore the nature of speciation over the edge of this biogeographic divide, we used genomic data to test for evidence of gene flow between macaque species across Wallace's Line after macaques colonized Sulawesi. We recovered evidence of post-colonization gene flow, most prominently on the X chromosome. These results are consistent with the proposal that gene flow is a pervasive component of speciation—even when barriers to gene flow seem almost insurmountable.

诸多陆生脊椎动物类群仅分布于东南亚婆罗洲与苏拉威西岛之间的华莱士线（Wallace's Line）单侧，并在此独立完成演化分化；而该线正是全球最显著的生物地理过渡带之一。猕猴属在脊椎动物类群中实属罕见，其分布范围横跨华莱士线两侧，这引发了核心科学问题：跨越该生物地理屏障的扩散事件，究竟是单次演化偶然事件，还是更为持久的跨区交流？若为后者，其会带来怎样的基因组层面演化后果？为探究该生物地理分界边缘的物种形成本质，本研究借助全基因组数据，检验了猕猴属殖民苏拉威西岛后，跨华莱士线的猕猴物种间是否存在基因交流的证据。本研究成功检测到殖民后基因交流的信号，其中尤以X染色体上的信号最为显著。上述结果与"基因交流是物种形成过程中普遍存在的组成部分"这一假说相符，即便此时的基因流屏障看似几乎无法逾越。