Molecular data and ecological niche modelling reveal the Pleistocene history of a semi‐aquatic bug (Microvelia douglasi douglasi) in East Asia

Abstract

This study investigated the Pleistocene history of a semi-aquatic bug, Microvelia douglasi douglasi Scott, 1874 (Hemiptera: Veliidae) in East Asia. We used M. douglasi douglasi as a model species to explore the effects of historical climatic fluctuations on montane semi-aquatic invertebrate species. Two hypotheses were developed using ecological niche models (ENMs). First, we hypothesized that M. douglasi douglasi persisted in suitable habitats in southern Guizhou, southern Yunnan, Hainan, Taiwan and southeast China during the LIG. After that, the populations expanded (Hypothesis 1). As the spatial prediction in the LGM was significantly larger than in the LIG, we then hypothesized that the population expanded during the LIG to LGM transition (Hypothesis 2). We tested these hypotheses using mitochondrial data (COI+COII) and nuclear data (ITS1+5.8S+ITS2). Young lineages, relatively deep splits, lineage differentiation among mountain ranges in central, south and southwest China and high genetic diversities were observed in these suitable habitats. Evidence of mismatch distributions and neutrality tests indicate that a population expansion occurred in the late Pleistocene. The Bayesian skyline plot (BSP) revealed an unusual population expansion that likely happened during the cooling transition between LIG and LGM. The results of genetic data were mostly consistent with the spatial predictions from ENM, a finding that can profoundly improve phylogeographic research. The ecological requirements of M. douglasi douglasi, together with the geographical heterogeneity and climatic fluctuations of Pleistocene in East Asia, could have shaped this unusual demographic history. Our study contributes to our knowledge of semi-aquatic bug/invertebrate responses to Pleistocene climatic fluctuations in East Asia.

Pleistocene sea level fluctuation and host plant habitat requirement influenced the historical phylogeography of the invasive species Amphiareus obscuriceps (Hemiptera: Anthocoridae) in its native range

“…In these examples, a nearly homogenized genetic pattern was observed in the chloroplast/mitochondria/nuclear DNA sequences on both sides of the ECS land bridge (i.e., Mainland China and Japan). These observations are consistent with the large expanses of suitable spaces across the ECS land bridge reconstructed by paleoclimate niche modeling [5, 7]. …”

“…The ECS land bridge, along with the sea level decline during the LGM, might have connected species or population distribution, either serving as a dispersal corridor, allowing continuous migration of many temperate species from the mainland China into Japan (or vice versa), or generating secondary contact or gene flow among the formerly isolated populations. This “dispersal corridor” hypothesis is supported by the extant distribution of several species, including the deciduous orient oak Quercus variabilis Blume, 1850 [5], the marine gastropod Thais clavigera (Küster, 1860) [6], and the semiaquatic insect Microvelia douglasi douglasi Scott, 1874 [7]. In these examples, a nearly homogenized genetic pattern was observed in the chloroplast/mitochondria/nuclear DNA sequences on both sides of the ECS land bridge (i.e., Mainland China and Japan).…”

Long‐distance dispersal or postglacial contraction? Insights into disjunction between Himalaya–Hengduan Mountains and Taiwan in a cold‐adapted herbaceous genus, Triplostegia

“…TW populations are all from the central mountain range of Taiwan (average elevation: 2,321 m) and possess five cpDNA and six ITS haplotypes. Strong geography‐haplotype‐correlated genetic structures were also detected in birds (Qu et al., 2015; Wang et al., 2013), insects (Ye et al., 2014), and plants (Gao et al., 2007; Meng et al., 2017), which highlight the importance of topographic complexity in promoting species differentiation both by increasing habitat diversity and limiting gene flow between elevation‐restricted populations (Hoorn, Mosbrugger, Mulch, & Antonelli, 2013; Verboom, Bergh, Haiden, Hoffmann, & Britton, 2015). …”

“…There are over 100 species pairs that show disjunct distributions between HHM and TW (Ye et al., 2012). Based on previous studies (Lu et al., 2001; Wang et al., 2013; Ye, Zhu, Chen, Zhang, & Bu, 2014), two hypotheses have been proposed to elucidate the formation of the HHM‐TW disjunction: long‐distance dispersal and postglacial contraction.…”

“…Phylogeographic study of Cunninghamia revealed that populations in Taiwan were derived from continental Asia via long‐distance seed dispersal (Lu et al., 2001). The postglacial contraction hypothesis states that many species had a continuous distribution from Mainland China to TW during the Quaternary glacial period, and disjunction between HHM and TW occurred when taxa migrated to higher altitudes as the Earth became warmer (Chen et al, 2012; Wang, 1989; Wang et al., 2013; Ye et al., 2014). Most disjunct genera and species between HHM and TW are herbaceous (Chen, Ying, & Lu, 2012; Ye et al., 2012).…”