Abstract:
AbstractThe sub-Antarctic terrestrial ecosystems survive on isolated oceanic islands in the path of circumpolar currents and winds that have raged for more than 30 million years and are shaped by climatic cycles that surpass the tolerance limits of many species. Surprisingly little is known about how these ecosystems assembled their native terrestrial fauna and how such processes have changed over time. Here, we demonstrate the patterns and timing of colonization and speciation in the largest and dominant arthropod predators in the eastern sub-Antarctic: spiders of the genus Myro. Our results indicate that this lineage originated from Australia before the Plio-Pleistocenic glacial cycles and underwent an adaptive radiation on the Crozet archipelago, from where one native species colonized multiple remote archipelagos via the Antarctic circumpolar current across thousands of kilometers. The results indicate limited natural connectivity between terrestrial macroinvertebrate faunas in the eastern sub-Antarctic and partial survival of repeated glaciations in the Plio-Pleistocene. Furthermore, our findings highlight that by integrating arthropod taxa from multiple continents, the climatically more stable volcanic Crozet archipelago played a critical role in the evolution and distribution of arthropod life in the sub-Antarctic.
摘要:
亚南极陆地生态系统在孤立的海洋岛屿上生存,环极流和狂风的路径已经超过3000万年,并受到气候周期的影响,超过了许多物种的容忍极限。令人惊讶的是,人们对这些生态系统如何组装其原生陆地动物以及这些过程如何随着时间的推移而变化知之甚少。这里,我们展示了南极洲东部最大和主要的节肢动物捕食者:Myro属蜘蛛的定殖和物种形成的模式和时间。我们的结果表明,这种血统起源于澳大利亚,在Plio-pleistoconic冰川周期之前,并在Crozet群岛上进行了适应性辐射,从那里,一个本地物种通过数千公里的南极环极流在多个偏远的群岛上定居。结果表明,南极东部的陆地大型无脊椎动物动物区系与上更新世反复冰川的部分生存之间的自然连通性有限。此外,我们的发现强调,通过整合来自多个大陆的节肢动物类群,气候更稳定的火山Crozet群岛在亚南极节肢动物生命的演变和分布中起着至关重要的作用。