Phylogeography of two Sulawesi rodents: Testing the Effect of Climatic Variation on Population Structure

In order to support effective conservation and sustainable land management, it is important to understand the population structure and rates of population differentiation in lesser-known species. Biogeographers, evolutionary biologists and ecologist share an interest in learning about patterns of species diversity, and the identification of such a pattern (e.g. the effects of Pleistocene glacial cycles) can help predict levels of diversity according to the most likely evolutionary history of a species. A phylogenetic study focusing on the population genetics and phylogeography of two sympatric Indonesian murids (Maxomys hellwaldi & Bunomys andrewsi) was performed on different populations on the islands of Sulawesi and Buton. Indicators for population differentiation due to genetic structure were calculated using RAD-tagged Illumina sequencing data. Phylogenetic consensus trees were created using BEAST and MrBayes and dated on the basis of published references. Two hypotheses were tested, firstly that the putative populations are cryptic species, secondly that a defined geological event equally affected the evolutionary biology of both species of interest. A significant amount of differentiation was found between populations of each species on the different islands over a small geographic range. It was concluded that island colonisations during the early Pleistocene associated with the Pliocene to Pleistocene transition and its impact on sea level had resulted in incipient speciation in each genus in parallel

Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of spiny mice (Acomys dimidiatus) in St. Katherine’s Protectorate, Sinai, Egypt

The importance of parasites as a selective force in host evolution is a topic of current interest. However, short-term ecological studies of host-parasite systems, on which such studies are usually based, provide only snap-shots of what may be dynamic systems. We report here on four surveys, carried out over a period of 12 years, of helminths of spiny mice (Acomys dimidiatus), the numerically dominant rodents inhabiting the dry montane wadis in the Sinai Peninsula. With host age (age-dependent effects on prevalence and abundance were prominent) and sex (female bias in abundance in helminth diversity and in several taxa including Cestoda) taken into consideration, we focus on the relative importance of temporal and spatial effects on helminth infracommunities. We show that site of capture is the major determinant of prevalence and abundance of species (and higher taxa) contributing to helminth community structure, the only exceptions being Streptopharaus spp. and Dentostomella kuntzi. We provide evidence that most (notably the Spiruroidea, Protospirura muricola, Mastophorus muris and Gongylonema aegypti, but with exceptions among the Oxyuroidae e.g. Syphacia minuta), show elements of temporal-site stability, with rank order of measures among sites remaining similar over successive surveys and hence some elements of predictability in these systems

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements