Historical domestication-driven population expansion of the dung beetle Gymnopleurus mopsus (Coleoptera: Scarabaeidae) from its last refuge in Mongolia

Ji Hyoun Kang,Sang Woo Seok,Tae Joong Yoon,Sung Hwan Park,Chang Seob Lim,Yeon Jae Bae,Badamdorj Bayartogtokh

doi:10.1038/s41598-018-22182-3

Ji Hyoun Kang, Sang Woo Seok + Show 5 more

Open Access

https://doi.org/10.1038/s41598-018-22182-3

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Abstract

Populations of Gymnopleurus mopsus (family Scarabaeidae), a dung beetle that displays dung-rolling behavior (i.e., a telecoprid), have recently experienced sharp declines, and many populations are now at high risk of local extinction. However, Mongolia, which constitutes a major portion of the species’ distribution, still sustains a relatively large population. Here, we used mitochondrial COI sequences to investigate the within-population genetic diversity and both the genetic and phylogeographic structures of 24 G. mopsus populations across the species’ main distribution in Mongolia. Several lines of evidence indicated that the phylogeographic structure of G. mopsus had been influenced by a recent and sudden demographic expansion. Interestingly, the expansion of Mongolia’s G. mopsus population corresponded to the advent of livestock domestication in the region, and the species’ genetic structure coincided with road networks, which presumably serve as migration routes for livestock that might mediate the beetle’s dispersal. In addition, we also found that G. mopsus possesses high levels of haplotype diversity, which is generally indicative of large effective population sizes (Ne). Overall, the present study contributes to the current understanding of G. mopsus’ demographic history and dispersal patterns and also provides valuable information for the species’ conservation and management.

Highlights

Copronecrophagous dung beetles possess specialized ecological ability and behavior, in that they utilize feces as food, habitat, and breeding ground, and this extraordinary case of ecological specialization has likely contributed to their evolutionary success[1]
Among 418 cytochrome oxidase I gene (COI) sequences (658 bp) that were generated from G. mopsus specimens collected in Mongolia (N = 406), as well 12 specimens from Korea, China, and France, we identified 94 polymorphic sites and a total of 230 haplotypes (Table 1, Fig. 1)
The 14 populations that were represented by more than ten samples (N > 10) were included in downstream population genetic analyses, whereas the samples from all 27 sampling localities were used for haplotype network analysis, and those from the 24 sampling localities in Mongolia were used for analysis of molecular variance (AMOVA) (Table 1)

Summary

Introduction

Copronecrophagous dung beetles (subfamily Scarabaeinae) possess specialized ecological ability and behavior, in that they utilize feces as food, habitat, and breeding ground, and this extraordinary case of ecological specialization has likely contributed to their evolutionary success[1] These dung beetles are thought to play important ecological roles, such as nutrient recycling, bioturbation, plant growth promotion, seed dispersal, and parasite control, in terrestrial ecosystems[2,3] and, as a result, have become a focus of both biodiversity and conservation research, especially owing to their broad range of responses to environmental changes and strong ecological interactions with a diverse array of organisms, including plants, vertebrates, and invertebrates[4]. Analysis of both population genetic and phylogeographic structures could elucidate the historic migration, dispersal, and demography, and the G. mopsus populations in Mongolia present a promising model system for understanding the effects of mammal (e.g., cattle, sheep, and camels) abundance and distribution on the animal-mediated dispersal patterns of dung beetles

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