西村先生講話 第二回

Nexus file containing phased alleles from BDNF sequences of Sunda shelf Crocidura. This alignment was used to generate the gene trees in Figures S1 and S

Comparative Population Genomics of African Montane Forest Mammals Support Population Persistence across a Climatic Gradient and Quaternary Climatic Cycles

The Eastern Afromontane biodiversity hotspot (EABH) has the highest concentration of biodiversity in tropical Africa, yet few studies have investigated recent historical diversification processes in EABH lineages. Herein, we analyze restriction-site associated DNA-sequences (RAD-Seq) to study recent historical processes in co-distributed mouse (Hylomyscus) and shrew (Sylvisorex) species complexes, with an aim to better determine how historical paleoenvironmental processes might have contributed to the EABH’s high diversity. We analyzed complete SNP matrices of \u3e 50,000 RAD loci to delineate populations, reconstruct the history of isolation and admixture, and discover geographic patterns of genetic partitioning. These analyses demonstrate that persistently unsuitable habitat may have isolated multiple populations distributed across montane habitat islands in the Itombwe Massif and Albertine Rift to the west as well as Mt Elgon and Kenyan Highlands to the east. We detected low genetic diversity in Kenyan Highland populations of both genera, consistent with smaller historical population sizes in this region. We additionally tested predictions that Albertine Rift populations are older and more persistently isolated compared to the Kenyan Highlands. Phylogenetic analyses support greater historical isolation among Albertine Rift populations of both shrews and mice compared to the Kenyan Highlands and suggest that there are genetically isolated populations from both focal genera in the Itombwe Massif, Democratic Republic of Congo. The Albertine Rift ecoregion has the highest mammalian tropical forest species richness per unit area on earth. Our results clearly support accelerating efforts to conserve this diversity

A revision of pipistrelle-like bats (Mammalia: Chiroptera: Vespertilionidae) in East Africa with the description of new genera and species

Vespertilionidae (class Mammalia) constitutes the largest family of bats, with ~500 described species. Nonetheless, the systematic relationships within this family are poorly known, especially among the pipistrelle-like bats of the tribes Vespertilionini and Pipistrellini. Perhaps as a result of their drab pelage and lack of obvious morphological characters, the genus and species limits of pipistrelle-like bats remain poorly resolved, particularly in Africa, where more than one-fifth of all vesper bat species occur. Further exacerbating the problem is the accelerating description of new species within these groups. In this study, we attempt to resolve the systematic relationships among the pipistrelle-like bats of sub-Saharan Africa and Madagascar and provide a more stable framework for future systematic efforts. Our systematic inferences are based on extensive genetic and morphological sampling of > 400 individuals covering all named genera and the majority of described African pipistrelle-like bat species, focusing on previously unstudied samples of East African bats. Our study corroborates previous work by identifying three African genera in Pipistrellini (Pipistrellus, Scotoecus and Vansonia), none of which is endemic to Africa. However, the situation is more complex in Vespertilionini. With broad taxonomic sampling, we confirm that the genus Neoromicia is paraphyletic, a situation that we resolve by assigning the species of Neoromicia to four genera. Neoromicia is here restricted to Neoromicia zuluensis and allied taxa. Some erstwhile Neoromicia species are transferred into an expanded Laephotis, which now includes both long-eared and short-eared forms. We also erect two new genera, one comprising a group of mostly forest-associated species (many of which have white wings) and the other for the genetically and morphologically unique banana bat. All four of these genera, as recognized here, are genetically distinct, have distinctive bacular morphologies and can be grouped by cranial morphometrics. We also demonstrate that the genus Nycticeinops, until now considered monospecific, includes both Afropipistrellus and the recently named Parahypsugo, thus representing the fifth African genus in Vespertilionini. A sixth genus, Hypsugo, is mostly extra-limital to sub-Saharan Africa. Finally, we describe three new species of pipistrelle-like bats from Kenya and Uganda, uncovered during the course of systematic bat surveys in the region. Such surveys are greatly needed across tropical Africa to uncover further bat diversity.https://academic.oup.com/zoolinneanhj2022Mammal Research InstituteZoology and Entomolog

Integrative taxonomy and phylogeography of Colomys and Nilopegamys (Rodentia: Murinae), semi-aquatic mice of Africa, with descriptions of two new species

The semi-aquatic African murine genera Colomys and Nilopegamys are considered monotypic and thought to be closely related to one another. Colomys occurs across forested regions of equatorial Africa, whereas Nilopegamys is known only from the Ethiopian holotype, making it among the rarest mammalian genera in the world – and possibly extinct. Using morphological and genetic data, we reassess the taxonomy of Colomys and Nilopegamys. A multilocus phylogeny with outgroups demonstrates that Nilopegamys is sister to Colomys. In addition, we recognize at least four morphologically diagnosable and genetically distinct species within Colomys: C. eisentrauti (elevated from subspecies and restricted to north-west Cameroon), C. goslingi (with a more restricted range than previously reported) and two new species (one from Liberia and Guinea and one from central and southern Democratic Republic of the Congo and Angola). We also review the status of four other taxa currently recognized within Colomys goslingi (bicolor, denti, goslingi and ruandensis) and demonstrate that these names lack phylogenetic and/or morphological support. Finally, we discuss potential biogeographic barriers that may have played a role in the evolution of Colomys and Nilopegamys, emphasizing the importance of rivers in both facilitating and, possibly, limiting dispersal within these genera.https://academic.oup.com/zoolinneanhj2022Mammal Research InstituteZoology and Entomolog

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM