López-Antoñanzas Raquel, Knoll Fabien, Wan Shiming, Flynn Lawrence J
1] School of Earth Sciences, University of Bristol, Bristol, United Kingdom [2] Departamento de Paleobiología, Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain.
1] School of Earth Sciences, University of Bristol, Bristol, United Kingdom [2] School of Earth, Atmospheric &Environmental Sciences, University of Manchester, Manchester, United Kingdom [3] Departamento de Paleobiología, Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain.
Sci Rep. 2015 Mar 11;5:9008. doi: 10.1038/srep09008.
The modern Asian monsoonal systems are currently believed to have originated around the end of the Oligocene following a crucial step of uplift of the Tibetan-Himalayan highlands. Although monsoon possibly drove the evolution of many mammal lineages during the Neogene, no evidence thereof has been provided so far. We examined the evolutionary history of a clade of rodents, the Rhizomyinae, in conjunction with our current knowledge of monsoon fluctuations over time. The macroevolutionary dynamics of rhizomyines were analyzed within a well-constrained phylogenetic framework coupled with biogeographic and evolutionary rate studies. The evolutionary novelties developed by these rodents were surveyed in parallel with the fluctuations of the Indian monsoon so as to evaluate synchroneity and postulate causal relationships. We showed the existence of three drops in biodiversity during the evolution of rhizomyines, all of which reflected elevated extinction rates. Our results demonstrated linkage of monsoon variations with the evolution and biogeography of rhizomyines. Paradoxically, the evolution of rhizomyines was accelerated during the phases of weakening of the monsoons, not of strengthening, most probably because at those intervals forest habitats declined, which triggered extinction and progressive specialization toward a burrowing existence.
现代亚洲季风系统目前被认为起源于渐新世末期，紧随青藏高原隆升这一关键步骤之后。尽管在新近纪期间季风可能推动了许多哺乳动物谱系的演化，但迄今为止尚未找到相关证据。我们结合当前关于季风随时间波动的知识，研究了啮齿动物一个分支——竹鼠亚科的演化历史。在一个受到严格限制的系统发育框架内，结合生物地理学和演化速率研究，分析了竹鼠的宏观演化动态。同时考察了这些啮齿动物所产生的演化新特征与印度季风波动的关系，以评估同步性并推测因果关系。我们发现竹鼠演化过程中存在三次生物多样性下降，所有这些都反映出灭绝率的升高。我们的结果表明季风变化与竹鼠的演化及生物地理学之间存在联系。矛盾的是，竹鼠的演化在季风减弱而非增强阶段加速，很可能是因为在这些时期森林栖息地减少，这引发了灭绝并促使其逐渐特化至穴居生活。
