Convergent evolution of the environmental adaptability of high-elevation populations of waist-shaped bugs

Aim: Similar environmental selection pressures drive the occurrence of convergent evolution among species. However, studies on this phenomenon are scarce at the population level. Here, we used two waist-shaped bugs to test the hypothesis that similar high-elevation habitat environments could lead to similar genetic adaptations among populations of different species.Location: East Asia.TaxaMalcus sinicus Stys, 1967 & Malcus insularis Stys, 1967.Methods: Population genetic structure was determined by phylogenetic and phylogeographical analyses. Demographic history was inferred by comparing simulated history models. Suitable habitat from the last interglacial period (LIG) to the present was predicted by ecological niche modelling (ENM). Convergent evolutionary processes were jointly assessed by the comparison of population ecological differences and the principal component analysis of environmentally related single-nucleotide polymorphisms (SNPs).Results: Our results showed that the land bridge in the Pleistocene helped ancestral populations of M. sinicus and M. insularis diffuse from mainland China to Taiwan Island. Subsequently, the geographical barrier imposed by the Taiwan Strait promoted the species differentiation. Geographic isolation and adaptive evolution jointly promoted the population differentiation in M. sinicus. Genetic similarity was found between the populations of M. sinicus in southwestern China (sin-YN) and M. insularis on Taiwan Island (ins-TW). Temperature-related environmental factors and elevation were found to similarly and significantly clustered with ins-TW and sin-YN and were clearly distinguished from the other low-/mid-elevation populations of M. sinicus (sin-EA). Furthermore, the SNPs related to these environmental factors presented the same clustering results.Main Conclusions: Our study revealed a novel disjunct distribution pattern between southwestern China and Taiwan Island at the population level and provided evidence of convergent evolution of local populations in high-elevation environments. Here, we revealed that similar environmental selection pressures can drive the occurrence of convergent evolution at the population level among different species.

Automated summary

This study reveals a novel disjunct distribution pattern at the population level between southwestern China and Taiwan Island, providing evidence of convergent evolution of local populations in high-elevation environments.