Orogeny shapes the diversification of an ancient and relict spider family (Hypochilidae), with the stepwise uplift of the Qinghai-Tibetan plateau driving the radiation of Asian lineages

Mountain uplift has been recognized as a critical driver of adaptive evolution and species diversification. Hypochilidae, an ancient and relict spider family, is predominantly found in montane regions. However, the factors promoting speciation within this family remain poorly understood. We utilized multi-locus data from 97% of Hypochilidae species, including 27 mitochondrial genomes, to construct a robust phylogenetic tree. Time-calibrated analyses reveal that Hypochilidae originated in the Late Jurassic period. In North America, the genus Hypochilus diversified in association with relatively ancient orogenic events, particularly the uplift of the Rocky Mountains, California Mountains, and southern Appalachians, which mainly occurred prior to the Oligocene. In contrast, the Asian genus Ectatosticta exhibited a rapid diversification pattern, spreading from the southern to the northeastern regions of the Qinghai-Tibet Plateau (QTP) after the Miocene. The species accumulation and net diversification rates of Asian Ectatosticta were significantly higher than those of North American Hypochilus, with a notable acceleration in diversification rates observed in BAMM software. Mountain orogeny has profoundly influenced the speciation of the ancient and relict spider family Hypochilidae, with the stepwise uplift of the QTP driving the diversification and radiation of Asian lineages.