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1. Extrinsically reinforced hybrid speciation within Holarctic ermine ( Mustela spp.) produces an insular endemic

   https://doi.org/10.1111/ddi.13234  

   Colella, Jocelyn P. ; Frederick, Lindsey M. ; Talbot, Sandra L. ; Cook, Joseph A. ; Brito, ed., José ( February 2021 , Diversity and Distributions)

   Refugial isolation during glaciation is an established driver of speciation; however, the opposing role of interglacial population expansion, secondary contact, and gene flow on the diversification process remains less understood. The consequences of glacial cycling on diversity are complex and especially so for archipelago species, which experience dramatic fluctuations in connectivity in response to both lower sea levels during glacial events and increased fragmentation during glacial recession. We test whether extended refugial isolation has led to the divergence of genetically and morphologically distinct species within Holarctic ermine (Mustela erminea), a small cosmopolitan carnivore species that harbours 34 extant subspecies, 14 of which are insular endemics.

   Holarctic.

   We use genetic sequences (complete mitochondrial genomes, four nuclear genes) from >100 ermine (stoats) and geometric morphometric data for >200 individuals (27 of the 34 extant subspecies) from across their Holarctic range to provide an integrative perspective on diversification and endemism across this complex landscape. Multiple species delimitation methods (iBPP,bPTP) assessed congruence between morphometric and genetic data.

   Our results support the recognition of at least three species within theM. ermineacomplex, coincident with three of four genetic clades, tied to diversification in separate glacial refugia. We found substantial geographic variation within each species, with geometric morphometric results largely consistent with historical infraspecific taxonomy.

   Phylogeographic structure mirrors patterns of diversification in other Holarctic species, with a major Nearctic‐Palearctic split, but with greater intraspecific morphological diversity. Recognition of insular endemic speciesM. haidarumis consistent with a deep history of refugial persistence and highlights the urgency of mindful management of island populations along North America's North Pacific Coast. Significant environmental modification (e.g. industrial‐scale logging, mining) has been proposed for a number of these islands, which may elevate the risk of extinction of insular palaeoendemics.

    

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2. Predicted structural differences of four fertility‐related Y‐chromosome proteins in Macaca mulatta , M.fascicularis , and their Indochinese hybrids

   https://doi.org/10.1002/prot.26021  

   Ruiz, Cody A. ; Chaney, Morgan E. ; Imamura, Masanori ; Imai, Hiroo ; Tosi, Anthony J. ( November 2020 , Proteins: Structure, Function, and Bioinformatics)

   Species in the genusMacacatypically live in multimale‐multifemale social groups with male macaques exhibiting some of the largest testis: body weight ratios among primates. Males are believed to experience intense levels of sperm competition. Several spermatogenesis genes are located on the Y‐chromosome and, interestingly, occasional hybridization between two species has led to the introgression of the rhesus macaque (Macaca mulatta) Y‐chromosome deep into the range of the long‐tailed macaque (M.fascicularis). These observations have led to the prediction that the successful introgression of the rhesus Y‐haplotype is due to functional differences in spermatogenesis genes compared to those of the native long‐tailed Y‐haplotype. We examine here four Y‐chromosomal loci—RBMY,XKRY, and two nearly identical copies ofCDY—and their corresponding protein sequences. The genes were surveyed in representative animals from north of, south of, and within the rhesus x long‐tailed introgression zone. Our results show a series of non‐synonymous amino acid substitutions present between the two Y‐haplotypes. Protein structure modeling via I‐TASSER revealed different folding patterns between the two species' Y‐proteins, and functional predictions via TreeSAAP further reveal physicochemical differences as a result of non‐synonymous substitutions. These differences inform our understanding of the evolution of primate Y‐proteins involved in spermatogenesis and, in turn, have biomedical implications for human male fertility.

    

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3. Population genetics of wild Macaca fascicularis with low‐coverage shotgun sequencing of museum specimens

   https://doi.org/10.1002/ajpa.24099  

   Yao, Lu ; Witt, Kelsey ; Li, Hongjie ; Rice, Jonathan ; Salinas, Nelson R. ; Martin, Robert D. ; Huerta‐Sánchez, Emilia ; Malhi, Ripan S. ( July 2020 , American Journal of Physical Anthropology)

   Long‐tailed macaques (Macaca fascicularis) are widely distributed throughout the mainland and islands of Southeast Asia, making them a useful model for understanding the complex biogeographical history resulting from drastic changes in sea levels throughout the Pleistocene. Past studies based on mitochondrial genomes (mitogenomes) of long‐tailed macaque museum specimens have traced their colonization patterns throughout the archipelago, but mitogenomes trace only the maternal history. Here, our objectives were to trace phylogeographic patterns of long‐tailed macaques using low‐coverage nuclear DNA (nDNA) data from museum specimens.

   We performed population genetic analyses and phylogenetic reconstruction on nuclear single nucleotide polymorphisms (SNPs) from shotgun sequencing of 75 long‐tailed macaque museum specimens from localities throughout Southeast Asia.

   We show that shotgun sequencing of museum specimens yields sufficient genome coverage (average ~1.7%) for reconstructing population relationships using SNP data. Contrary to expectations of divergent results between nuclear and mitochondrial genomes for a female philopatric species, phylogeographical patterns based on nuclear SNPs proved to be closely similar to those found using mitogenomes. In particular, population genetic analyses and phylogenetic reconstruction from the nDNA identify two major clades withinM. fascicularis: Clade A includes all individuals from the mainland along with individuals from northern Sumatra, while Clade B consists of the remaining island‐living individuals, including those from southern Sumatra.

   Overall, we demonstrate that low‐coverage sequencing of nDNA from museum specimens provides enough data for examining broad phylogeographic patterns, although greater genome coverage and sequencing depth would be needed to distinguish between very closely related populations, such as those throughout the Philippines.

    

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4. Leap‐frog dispersal and mitochondrial introgression: Phylogenomics and biogeography of Limnonectes fanged frogs in the Lesser Sundas Archipelago of Wallacea

   https://doi.org/10.1111/jbi.13526  

   Reilly, Sean B. ; Stubbs, Alexander L. ; Karin, Benjamin R. ; Bi, Ke ; Arida, Evy ; Iskandar, Djoko T. ; McGuire, Jimmy A. ( February 2019 , Journal of Biogeography)

   The Lesser Sunda Islands are situated between the Sunda and Sahul Shelves, with a linear arrangement that has functioned as a two‐way filter for taxa dispersing between the Asian and Australo‐Papuan biogeographical realms. Distributional patterns of many terrestrial vertebrates suggest a stepping‐stone model of island colonization. Here we investigate the timing and sequence of island colonization in Asian‐origin fanged frogs from the volcanic Sunda Arc islands with the goal of testing the stepping‐stone model of island colonization.

   The Indonesian islands of Java, Lombok, Sumbawa, Flores and Lembata.

   Limnonectes dammermaniandL. kadarsani(Family: Dicroglossidae)

   MitochondrialDNAwas sequenced from 153 frogs to identify major lineages and to select samples for an exon‐capture experiment. We designed probes to capture sequence data from 974 exonic loci (1,235,981 bp) from 48 frogs including the outgroup species,L. microdiscus. The resulting data were analysed using phylogenetic, population genetic and biogeographical model testing methods.

   The mtDNAphylogeny findsL. kadarsaniparaphyletic with respect toL. dammermani, with a pectinate topology consistent with the stepping‐stone model. Phylogenomic analyses of 974 exons recovered the two species as monophyletic sister taxa that diverged ~7.6 Ma with no detectable contemporary gene flow, suggesting introgression of theL. dammermanimitochondrion intoL. kadarsanion Lombok resulting from an isolated ancient hybridization event ~4 Ma. WithinL. kadarsani,the Lombok lineage diverged first while the Sumbawa and Lembata lineages are nested within a Flores assemblage composed of two parapatrically distributed lineages meeting in central Flores. Biogeographical model comparison found strict stepping‐stone dispersal to be less likely than models involving leap‐frog dispersal events.

   These results suggest that the currently accepted stepping‐stone model of island colonization might not best explain the current patterns of diversity in the archipelago. The high degree of genetic structure, large divergence times, and absent or low levels of migration between lineages suggests thatL. kadarsanirepresents five distinct species.

    

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5. Global patterns of genomic and phenotypic variation in the invasive harlequin ladybird

   https://doi.org/10.1186/s12915-023-01638-7  

   Li, Hongran ; Peng, Yan ; Wang, Yansong ; Summerhays, Bryce ; Shu, Xiaohan ; Vasquez, Yumary ; Vansant, Hannah ; Grenier, Christy ; Gonzalez, Nicolette ; Kansagra, Khyati ; et al ( December 2023 , BMC Biology)

   The harlequin ladybirdHarmonia axyridis(Coleoptera: Coccinellidae), native to Asia, has been introduced to other major continents where it has caused serious negative impacts on local biodiversity. Though notable advances to understand its invasion success have been made during the past decade, especially with then newer molecular tools, the conclusions reached remain to be confirmed with more advanced genomic analyses and especially using more samples from larger geographical regions across the native range. Furthermore, althoughH. axyridisis one of the best studied invasive insect species with respect to life history traits (often comparing invasive and native populations), the traits responsible for its colonization success in non-native areas warrant more research.

   Our analyses of genome-wide nuclear population structure indicated that an eastern Chinese population could be the source of all non-native populations and revealed several putatively adaptive candidate genomic loci involved in body color variation, visual perception, and hemolymph synthesis. Our estimates of evolutionary history indicate (1) asymmetric migration with varying population sizes across its native and non-native range, (2) a recent admixture between eastern Chinese and American populations in Europe, (3) signatures of a large progressive, historical bottleneck in the common ancestors of both populations and smaller effective sizes of the non-native population, and (4) the southwest origin and subsequent dispersal routes within its native range in China. In addition, we found that while two mitochondrial haplotypes-Hap1 and Hap2 were dominant in the native range, Hap1 was the only dominant haplotype in the non-native range. Our laboratory observations in both China and USA found statistical yet slight differences between Hap1 and Hap2 in some of life history traits.

   Our study onH.axyridisprovides new insights into its invasion processes into other major continents from its native Asian range, reconstructs a geographic range evolution across its native region China, and tentatively suggests that its invasiveness may differ between mitochondrial haplotypes.

    

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