Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495, Japan.
Faculty of Tropical AgriScience, Czech University of Life Sciences, Kamýcká 129, 165 00 Prague 6 Suchdol, Czech Republic.
Proc Biol Sci. 2022 May 25;289(1975):20220246. doi: 10.1098/rspb.2022.0246.
Termites feed on vegetal matter at various stages of decomposition. Lineages of wood- and soil-feeding termites are distributed across terrestrial ecosystems located between 45°N and 45°S of latitude, a distribution they acquired through many transoceanic dispersal events. While wood-feeding termites often live in the wood on which they feed and are efficient at dispersing across oceans by rafting, soil-feeders are believed to be poor dispersers. Therefore, their distribution across multiple continents requires an explanation. Here, we reconstructed the historical biogeography and the ancestral diet of termites using mitochondrial genomes and δC and δN stable isotope measurements obtained from 324 termite samples collected in five biogeographic realms. Our biogeographic models showed that wood-feeders are better at dispersing across oceans than soil-feeders, further corroborated by the presence of wood-feeders on remote islands devoid of soil-feeders. However, our ancestral range reconstructions identified 33 dispersal events among biogeographic realms, 18 of which were performed by soil-feeders. Therefore, despite their lower dispersal ability, soil-feeders performed several transoceanic dispersals that shaped the distribution of modern termites.
白蚁以不同分解阶段的植物物质为食。分布在北纬 45°至南纬 45°之间的陆地生态系统中，存在着以木材和土壤为食的白蚁谱系，它们通过多次跨洋扩散事件获得了这种分布。虽然以木材为食的白蚁通常生活在它们赖以生存的木材中，并且能够通过木筏有效地在海洋中扩散，但土壤食者被认为是扩散能力较差的生物。因此，它们在多个大陆上的分布需要一个解释。在这里，我们使用线粒体基因组和从五个生物地理区域收集的 324 个白蚁样本中获得的 δC 和 δN 稳定同位素测量值，重建了白蚁的历史生物地理学和祖先饮食。我们的生物地理模型表明，以木材为食的白蚁比以土壤为食的白蚁更擅长在海洋中扩散，这进一步证实了在没有土壤食者的偏远岛屿上存在以木材为食的白蚁。然而，我们的祖先范围重建确定了 33 次生物地理区域之间的扩散事件，其中 18 次是由土壤食者完成的。因此，尽管土壤食者的扩散能力较低，但它们还是进行了几次跨洋扩散，从而塑造了现代白蚁的分布。
