| 1. |
- Jiang, Zhiyong, et al.
(författare)
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Gene flow and an anomaly zone complicate phylogenomic inference in a rapidly radiated avian family (Prunellidae)
- 2024
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Ingår i: BMC Biology. - : BioMed Central (BMC). - 1741-7007. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundResolving the phylogeny of rapidly radiating lineages presents a challenge when building the Tree of Life. An Old World avian family Prunellidae (Accentors) comprises twelve species that rapidly diversified at the Pliocene-Pleistocene boundary.ResultsHere we investigate the phylogenetic relationships of all species of Prunellidae using a chromosome-level de novo assembly of Prunella strophiata and 36 high-coverage resequenced genomes. We use homologous alignments of thousands of exonic and intronic loci to build the coalescent and concatenated phylogenies and recover four different species trees. Topology tests show a large degree of gene tree-species tree discordance but only 40-54% of intronic gene trees and 36-75% of exonic genic trees can be explained by incomplete lineage sorting and gene tree estimation errors. Estimated branch lengths for three successive internal branches in the inferred species trees suggest the existence of an empirical anomaly zone. The most common topology recovered for species in this anomaly zone was not similar to any coalescent or concatenated inference phylogenies, suggesting presence of anomalous gene trees. However, this interpretation is complicated by the presence of gene flow because extensive introgression was detected among these species. When exploring tree topology distributions, introgression, and regional variation in recombination rate, we find that many autosomal regions contain signatures of introgression and thus may mislead phylogenetic inference. Conversely, the phylogenetic signal is concentrated to regions with low-recombination rate, such as the Z chromosome, which are also more resistant to interspecific introgression.ConclusionsCollectively, our results suggest that phylogenomic inference should consider the underlying genomic architecture to maximize the consistency of phylogenomic signal.
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| 2. |
- Cao, Qi, et al.
(författare)
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Jointly estimating the most likely driving paths and destination locations with incomplete vehicular trajectory data
- 2023
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Ingår i: Transportation Research, Part C: Emerging Technologies. - 0968-090X. ; 155
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Tidskriftsartikel (refereegranskat)abstract
- With an ever-increasing deployment density of probe and fixed sensors, massive vehicular trajectory data is available and show a promising foundation to improve the observability of dynamic traffic demand pattern. However, due to technical and privacy issues, the raw trajectories are not always complete and the paths and destinations between discontinuous trajectory nodes are usually missing. This paper proposes a probabilistic method to jointly reconstruct the missing driving path and destination location of vehicles with incomplete trajectory data. One problem-specific HMM-structured model incorporating spatial and temporal analysis (ST-HMM) is constructed to define the matching probability between observed data and possible movement. Two algorithms, namely candidate set generation and best-match search algorithms, are developed to seek the most possible one as matching result. It can implement end-to-end processing from incomplete trajectory data to complete and connective paths and destinations for the target vehicle. The proposed method is tested based on field-test data and city-wide road network. Compared with two benchmark methods, the proposed method improved the matching accuracy in terms of both path identification and destination inference. Additionally, sensitivity analyses on the size of training dataset and candidate set were performed. We believe that experiment results of these sensitivity analyses can help to provide guidance on data sensing and candidate generation.
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| 3. |
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| 4. |
- Chen, Yilin, et al.
(författare)
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The combination of genomic offset and niche modelling provides insights into climate change-driven vulnerability
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Global warming is increasingly exacerbating biodiversity loss. Populations locally adapted to spatially heterogeneous environments may respond differentially to climate change, but this intraspecific variation has only recently been considered when modelling vulnerability under climate change. Here, we incorporate intraspecific variation in genomic offset and ecological niche modelling to estimate climate change-driven vulnerability in two bird species in the Sino-Himalayan Mountains. We found that the cold-tolerant populations show higher genomic offset but risk less challenge for niche suitability decline under future climate than the warm-tolerant populations. Based on a genome-niche index estimated by combining genomic offset and niche suitability change, we identified the populations with the least genome-niche interruption as potential donors for evolutionary rescue, i.e., the populations tolerant to climate change. We evaluated potential rescue routes via a landscape genetic analysis. Overall, we demonstrate that the integration of genomic offset, niche suitability modelling, and landscape connectivity can improve climate change-driven vulnerability assessments and facilitate effective conservation management.
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| 5. |
- Ji, Yanzhu, et al.
(författare)
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Orthologous microsatellites, transposable elements, and DNA deletions correlate with generation time and body mass in neoavian birds
- 2022
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 8:35
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Tidskriftsartikel (refereegranskat)abstract
- The rate of mutation accumulation in germline cells can be affected by cell replication and/or DNA damage, which are further related to life history traits such as generation time and body mass. Leveraging the existing datasets of 233 neoavian bird species, here, we investigated whether generation time and body mass contribute to the interspecific variation of orthologous microsatellite length, transposable element (TE) length, and deletion length and how these genomic attributes affect genome sizes. In nonpasserines, we found that generation time is correlated to both orthologous microsatellite length and TE length, and body mass is negatively correlated to DNA deletions. These patterns are less pronounced in passerines. In all species, we found that DNA deletions relate to genome size similarly as TE length, suggesting a role of body mass dynamics in genome evolution. Our results indicate that generation time and body mass shape the evolution of genomic attributes in neoavian birds.
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| 6. |
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| 7. |
- Qu, Gang, et al.
(författare)
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Enhancing the Performance of the p-n Heterostructure Electrolyte for Solid Oxide Fuel Cells via A-Site-Deficiency Engineering
- 2023
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 15:42, s. 49154-49169
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor ionic electrolytes are attracting growing interest for developing low-temperature solid oxide fuel cells (LT-SOFCs). Our recent study has proposed a p-n heterostructure electrolyte based on perovskite oxide BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) and ZnO, achieving promising fuel cell performance. Herein, to further improve the performance of the heterostructure electrolyte, an A-site-deficiency strategy is used to solely modify BCFZY for regulating the ionic conduction and catalytic activity of the heterostructure. Two new electrolytes, B0.9CFZY-ZnO and B0.8CFZY-ZnO, were developed and systematically studied. The results show that the two samples gain improved ionic conductivity and auxiliary catalytic activity after A-site deficiency as a result of the increment of the surface and interface oxygen vacancies. The single cells with B0.9CFZY-ZnO and B0.8CFZY-ZnO exhibit enhanced peak power outputs at 450-550 °C compared to the cell based on B1.0CFZY-ZnO (typically, 745 and 795 vs 542 mW cm-2 at 550 °C). Particular attention is paid to the impact of A-site deficiency on the interface energy band alignment between BxCFZY and ZnO, which suggests that the p-n heterojunction effect of BxCFZY-ZnO for charge carrier regulation can be tuned by A-site deficiency to enable high proton transport while avoiding fuel cell current leakage. This study thus confirms the feasibility of A-site-deficiency engineering to optimize the performance of the heterostructure electrolyte for developing LT-SOFCs.
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| 8. |
- Qu, Yanhua, 1974-, et al.
(författare)
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The evolution of ancestral and species-specific adaptations in snowfinches at the Qinghai-Tibet Plateau
- 2021
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 10.1073/pnas.2012398118:13, s. e2012398118-e2012398118
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Tidskriftsartikel (refereegranskat)abstract
- Species in a shared environment tend to evolve similar adaptations under the influence of their phylogenetic context. Using snowfinches, a monophyletic group of passerine birds (Passeridae), we study the relative roles of ancestral and species-specific adaptations to an extreme high-elevation environment, the Qinghai–Tibet Plateau. Our ancestral trait reconstruction shows that the ancestral snowfinch occupied high elevations and had a larger body mass than most nonsnowfinches in Passeridae. Subsequently, this phenotypic adaptation diversified in the descendant species. By comparing high-quality genomes from representatives of the three phylogenetic lineages, we find that about 95% of genes under positive selection in the descendant species are different from those in the ancestor. Consistently, the biological functions enriched for these species differ from those of their ancestor to various degrees (semantic similarity values ranging from 0.27 to 0.5), suggesting that the three descendant species have evolved divergently from the initial adaptation in their common ancestor. Using a functional assay to a highly selective gene, DTL, we demonstrate that the nonsynonymous substitutions in the ancestor and descendant species have improved the repair capacity of ultraviolet-induced DNA damage. The repair kinetics of the DTL gene shows a twofold to fourfold variation across the ancestor and the descendants. Collectively, this study reveals an exceptional case of adaptive evolution to high-elevation environments, an evolutionary process with an initial adaptation in the common ancestor followed by adaptive diversification of the descendant species.
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| 9. |
- Savas, Suleyman, et al.
(författare)
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Generating hardware and software for RISC-V cores generated with Rocket Chip generator
- 2021
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Ingår i: Proceedings - 34th IEEE International System-on-Chip Conference, SOCC 2021. - 2164-1676 .- 2164-1706. - 9781665429313 ; 2021-September, s. 89-94
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Konferensbidrag (refereegranskat)abstract
- This paper presents the hardware/software generation backend of a code generation framework. The backend aims at synthesizing complete systems based on RISC-V cores with accelerators from a single-language description. The framework takes the dataflow description of an algorithm as input and generates a combination of hardware (in Chisel) and software (in C) that interacts with the hardware. The hardware can be integrated with RISC-V cores created by the Rocket Chip generator and the software can be executed on these cores.The generated hardware requires similar amount of resources as the hand-written hardware while achieving equal or higher clock rates. As expected, the accelerators perform the calculations faster than the general purpose processor, 5 to 33x in our experiments. When these accelerators are integrated with the Rocket cores, they increase the performance by 25% and 260% in the two use-cases we investigate.
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| 10. |
- She, Huishang, et al.
(författare)
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Quantifying adaptive divergence of the snowfinches in a common landscape
- 2022
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Ingår i: Diversity & distributions. - : Wiley. - 1366-9516 .- 1472-4642. ; 28, s. 2579-2592
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Tidskriftsartikel (refereegranskat)abstract
- AimSpecies living in a shared environment face similar selective pressures and often evolve adaptive divergence to avoid competition. Quantifying phenotypic divergence and its genetic parallelism among sympatric species is important for understanding of ecologically moderated biodiversity. Here, we integrate ecologic, phenotypic and genomic datasets to study to what extent three sympatrically snowfinches (Montifringilla adamsi, Pyrgilauda ruficollis and Onychostruthus taczanowskii) differ in their adaptations in order to co-exist in a shared environment.LocationQinghai–Tibetan Plateau.MethodsWe used principal component analysis to summarize and compare environmental and phenotypic divergence. We compared phenotypes relevant to body and beak sizes (n = 68) because they are indicators of niche and food segregation, thus critical for establishing co-existence of sympatric birds. We used comparative genomics (n = 33) to identify genetic loci that are highly divergent between species as well as loci unique for each of species. Using vector analyses, we integrated correlation and permutation to quantify parallelism between phenotypic and genetic divergences.ResultsWe found that body and beak sizes are significantly different among three snowfinches. The phenotypic differentiations are greater in species that share similar ecological conditions than in those that do not. We showed that genes related to developmental process are over-represented within highly divergent genomic regions and unique genetic loci of each species. We found that the extent of phenotypic divergence between snowfinch pairs is more strongly correlated with the magnitude of divergence in developmental genes than in the whole genome.Main conclusionsAdaptive divergence of sympatric snowfinches is highly constrained on developmental genes. As this genetic divergence is strongly correlated with divergence of the traits related to segregation in niche and food resources, this correlation reflects either causal effects or indirect consequences of ecological mediated changes. Our study provides novel insights into the mechanisms underlying evolutionary versatility and ecological success among sympatric species.
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| 11. |
- Song, Gang, et al.
(författare)
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Great journey of Great Tits (Parus major group) : Origin, diversification and historical demographics of a broadly distributed bird lineage
- 2020
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Ingår i: Journal of Biogeography. - : WILEY. - 0305-0270 .- 1365-2699. ; 47:7, s. 1585-1598
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Tidskriftsartikel (refereegranskat)abstract
- Aim The Pleistocene glacial cycles play a prominent role in shaping phylogeographical patterns of organisms, while few studies have focused on the regional difference of glacial effects. By acquiring comprehensive knowledge of the origin, diversification and historical demography of an intensively studied passerine species complex, Great Tit, we aim to test the regional variation of the Late Pleistocene glaciation impacts on this widely distributed bird lineage. Location Eurasia and associated peninsulas and archipelagos. Taxa Parus major species complex. Methods Phylogeny, divergence times and demographic dynamics were estimated with Bayesian methods. Population structure, genetic diversity and correlation between genetic and physical distances were estimated based on mtDNA variation. Glacial-to-present distributional changes were assessed via ecological niche modelling (ENM). Results Five major clades (Central Asia, Eastern Asia, Eastern Himalaya, Northern and Western Eurasia and Southern Asia) were detected, with divergence times ranging 1.57-0.50 million years ago. Genetic diversity values and Bayesian skyline plots suggest that the three eastern clades had a deeper population history. A more complex geographic structure was observed in East Asia. Demographic expansion during the last glacial cycle was indicated for all five clades. ENM results showed broad conservatism of traits related to climate tolerances, and generally broader and more continuous distributional patterns under glacial conditions. Main Conclusions The Great Tit complex probably originated in Southeast Asia. Geographic barriers, such as the deserts of Central Asia and the Qinghai-Tibet Plateau appear to be related to the lineage divergence. Late Pleistocene climate cycles influenced both demographic dynamics and divergence, especially in terms of east-west differences in relation to geographic complexity.
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| 12. |
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| 13. |
- Zhang, Dezhi, et al.
(författare)
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Most Genomic Loci Misrepresent the Phylogeny of an Avian Radiation Because of Ancient Gene Flow
- 2021
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Ingår i: Systematic Biology. - : Oxford University Press. - 1063-5157 .- 1076-836X. ; 70:5, s. 961-975
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic trees based on genome-wide sequence data may not always represent the true evolutionary history for a variety of reasons. One process that can lead to incorrect reconstruction of species phylogenies is gene flow, especially if interspecific gene flow has affected large parts of the genome. We investigated phylogenetic relationships within a clade comprising eight species of passerine birds (Phylloscopidae, Phylloscopus, leafwarblers) using one de novo genome assembly and 78 resequenced genomes. Onthe basis of hypothesis-exclusion trials based on D-statistics, phylogenetic network analysis, and demographic inference analysis, we identified ancient gene flow affecting large parts of the genome between one species and the ancestral lineage of a sister species pair. This ancient gene flow consistently caused erroneous reconstruction of the phylogeny when using large amounts of genome-wide sequence data. In contrast, the true relationships were captured when smaller parts of the genome were analyzed, showing that the "winner-takes-all democratic majority tree" is not necessarily the true species tree. Under this condition, smaller amounts of data may sometimes avoid the effects of gene flow due to stochastic sampling, as hidden reticulation histories are more likely to emerge from the use of larger data sets, especially whole-genome data sets. In addition, we also found that genomic regions affected by ancient gene flow generally exhibited higher genomic differentiation but a lower recombination rate and nucleotide diversity. Our study highlights the importance of considering reticulation in phylogenetic reconstructions in the genomic era.
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| 14. |
- Zhang, Dezhi, et al.
(författare)
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Phylogenetic Conflict Between Species Tree and Maternally Inherited Gene Trees in a Clade of Emberiza Buntings (Aves: Emberizidae)
- 2023
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Ingår i: SYSTEMATIC BIOLOGY. - 1063-5157 .- 1076-836X.
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Tidskriftsartikel (refereegranskat)abstract
- Different genomic regions may reflect conflicting phylogenetic topologies primarily due to incomplete lineage sorting and/or gene flow. Genomic data are necessary to reconstruct the true species tree and explore potential causes of phylogenetic conflict. Here, we investigate the phylogenetic relationships of 4 Emberiza species (Aves: Emberizidae) and discuss the potential causes of the observed mitochondrial non-monophyly of Emberiza godlewskii (Godlewski's bunting) using phylogenomic analyses based on whole genome resequencing data from 41 birds. Analyses based on both the whole mitochondrial genome and similar to 39 kilobases from the non-recombining W chromosome reveal sister relationships between each the northern and southern populations of E. godlewskii with E. cioides and E. cia, respectively. In contrast, the monophyly of E. godlewskii is reflected by the phylogenetic signal of autosomal and Z chromosomal sequence data as well as demographic inference analyses, which-in combination-support the following tree topology: ([{E. godlewskii, E. cia}, E. cioides], E. jankowskii). Using D-statistics, we detected multiple gene flow events among different lineages, indicating pervasive introgressive hybridization within this clade. Introgression from an unsampled lineage that is sister to E. cioides or introgression from an unsampled mitochondrial + W chromosomal lineage of E. cioides into northern E. godlewskii may explain the phylogenetic conflict between the species tree estimated from genome-wide data versus mtDNA/W tree topologies. These results underscore the importance of using genomic data for phylogenetic reconstruction and species delimitation.
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