Niphadomimus
Creators: name: Grebennikov, Vasily V.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Curculionidae
Niphadomimus

description: Niphadomimus temporal phylogeography
The most significant phylogeographic result is the detection of the relatively robust Niphadomimus tree with the sister group relations between the Qinling species N. merope sp. n. and the rest of the genus. Similarly to the genus Niphadomimus, numerous other Animalia clades are restricted in their distribution to the highlands of the southeastern edges of the Tibetan Plateau (Fig. 14, Favre et al. 2014), i.e. the eastern Himalayas (Nepal, Sikkim, Bhutan and Arunachal Pradesh), the Hengduan mountains (northern Myanmar and the adjacent parts of SW China) and the Qinling mountain range (Shaanxi). The Red Panda (Ailurus fulgens Cuvier) presently ranges longitudinally through Sichuan, Yunnan, northern Myanmar, Bhutan, Sikkim and Nepal and unlike Niphadomimus it seems to be a recent inhabitant resulting from a post-glacial range expansion by this presumably highly mobile mammalian species (Le et al. 2005). The presumably less mobile Asian shrew-like moles (Uropsilus Milne-Edwards) have a distribution more closely matching that of Niphadomimus and exhibit a robust phylogeographic structure with their single sampled Qinling population nested deeply inside the Hengduan clade (Wan et al. 2013). The latter is not similar to the Niphadomimus pattern, where the Qinling species N. merope sp. n. forms the sister group to the rest from Hengduan (Fig. 14). The comparison of the Niphadomimus temporal phylogeography with the aforementioned examples should be done with caution, since they also rely on an a priori DNA substitution rate taken as the main dating source, which introduces a significant element of circular logic.
Only a few works on the low dispersing wingless weevils distributed in temperate mountains are detailed enough to permit adequate comparison with the reported Niphadomimus phylogeographic results. Among them, Meregalli et al. (2013) offers the best reference point being the most comparable in size and nature to the DNA data, as well as dealing with a genus of high altitude wingless weevils distributed along the southern edge of the last glacial maximum in South Europe. The authors utilized 775 nt of 18 CO1 haplotypes representing seven Dichotrachelus Stierlin species sampled on the southern slopes of the Alps. They reported the mean interspecies p - distance in the range of 11.0–16.7%, which by using the 2.1% MY -1 sequence divergence rate dated the speciation events between 6.5 MY and 3.3 MY, i.e. from later Miocene to late Pliocene. They concluded that instead of being the main force behind the Dichotrachelus phylogeographic structure, the Quaternary glaciation cycles are primary responsible for the highly fragmented present day high-altitude species distribution. For the most part the conclusions on Dichotrachelus phylogeography match those for Niphadomimus, and conceivably suggest a common pattern, even though both studies used a markedly different sequence divergence rate for the same CO1 gene (2.1% MY - 1 in Meregalli et al. 2013, as compare to 3.6% MY -1 adopted here).
Regardless of the uncertainties about the exact order of the bifurcation points in the (Niphadomimus except N. merope sp. n.) clade (compare Figs. 12 and 13), temporal analysis places all events leading to the origin of all presently recognised Niphadomimus species well before Pleistocene (the last dichotomy between N. celaeno sp. n. and N. strerope sp. n. taking place in mid Pliocene at about 3.64 MY; Fig. 13). These results add to the growing body of evidence denying the Pleistocene repeated glaciation and aridification effects of being the most important stimulus to the present day speciation. The mtDNA distance-based interpretation of Niphadomimus species diversification agrees well with the similar conclusions reached based on fossil records for the North American amphibians and reptiles (Holman 1995: 28) and mammals (Barnosky 2005). These similarities further corroborate the hypothesis that the Quaternary climatic changes do not represent the main driving force of the presently observed species diversity (Rull 2008). These Niphadomimus temporal results, however, should be taken only tentatively, since the generic tree (Fig. 13) is likely lacking many more extant branches for numerous hypothetically undetected species. If true, they will be likely inserted among those already known and some of them originating more recently, than what is presently hypothesised.
description: Published as part of Grebennikov, Vasily V., 2014, DNA barcode and phylogeography of six new high altitude wingless Niphadomimus (Coleoptera: Curculionidae: Molytinae) from Southwest China, pp. 151-173 in Zootaxa 3838 (2) on pages 168-169, DOI: 10.11646/zootaxa.3838.2.1, http://zenodo.org/record/4921799