Phylogenomics, reticulate evolution and spatiotemporal diversification in Anthocoris (Hemiptera: Anthociridae): impacts of repeated uplifts of the Qinghai–Tibetan Plateau across Eurasia

The Qinghai-Tibetan Plateau, the core of the Eurasian mountain belt, has repeatedly reshaped the formation and pattern of biodiversity through episodic uplift and associated geoclimatic changes. Despite its central role in shaping biotic evolution across Eurasia, genus-level studies that jointly evaluate the effects of orogeny, hybridization and ecological adaptation remain scarce. Here, we integrate multilocus phylogenomics (nuclear and mitochondrial), network-based reticulation inference, divergence dating, macroevolutionary modelling and codon-based molecular adaptation tests (branch-site dN/dS on protein-coding genes) to reconstruct the spatiotemporal diversification of the predatory insect genus Anthocoris across Eurasia. We identified two episodes of rapid lineage diversification: a basal radiation (BR; late Oligocene-Miocene, ~25-15 Ma) and a terminal radiation (TR; mid-Miocene to Pleistocene), supported by independent evidence from diversification rate shifts (e.g., ClaDS, CoMET) and dense clusters of short branches, with the strongest signals in high-elevation lineages. Genome-scale phylogenomic discordance points to incomplete lineage sorting and ancient introgression as joint drivers of these patterns, gauged by the extent of deep gene-tree conflict and independent genome-wide tests (quartet analyses and D-statistics), with network inference corroborating reticulation. The timing and geography of BR and TR align with major geoclimatic episodes: the formation of the modern Qinghai-Tibetan Plateau (~25-15 Ma), the subsequent formation of the Himalayas-Hengduan Mountains (~15 Ma onward), the closure of the Tethys Sea, Central Asian aridification and the Miocene cooling. Ancestral-range reconstructions place the origin of Anthocoris in northern Eurasia, and coupled with retention and sorting of ancestral polymorphism under niche conservatism, likely facilitated repeated high-elevation adaptation. This study provides new evidence and a theoretical framework showing that the repeated uplift of the Qinghai-Tibetan Plateau-acting with continent-wide geographic and climatic shifts and ancestral gene flow-jointly drove diversification and generated complex spatiotemporal patterns within genera across Eurasia.