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1. TreeHouseExplorer (THEx): A novel genome browser for phylogenomics.

   https://doi.org/10.1101/2022.01.03.474706  

   Harris, Andrew J.; Foley, Nicole M.; Williams, Tiffani; Murphy, William J. (January 2022, bioRxiv)

   Tree House Explorer (THEx) is a genome browser that integrates phylogenomic data and genomic annotations into a single interactive platform for combined analysis. THEx allows users to visualize genome-wide variation in evolutionary histories and genetic divergence on a chromosome-by-chromosome basis, with continuous sliding window comparisons to gene annotations, recombination rates, and other user-specified, highly customizable feature annotations. THEx provides a new platform for interactive phylogenomic data visualization to analyze and interpret the diverse evolutionary histories woven throughout genomes. Hosted on Conda, THEx integrates seamlessly into new or pre-existing workflows. 

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2. Out of Sight, Out of Mind: Widespread Nuclear and Plastid-Nuclear Discordance in the Flowering Plant Genus Polemonium (Polemoniaceae) Suggests Widespread Historical Gene Flow Despite Limited Nuclear Signal

   https://doi.org/10.1093/sysbio/syaa049  

   Rose, Jeffrey P; Toledo, Cassio A; Lemmon, Emily Moriarty; Lemmon, Alan R; Sytsma, Kenneth J; Carstens, Bryan (July 2020, Systematic Biology)

   Abstract Phylogenomic data from a rapidly increasing number of studies provide new evidence for resolving relationships in recently radiated clades, but they also pose new challenges for inferring evolutionary histories. Most existing methods for reconstructing phylogenetic hypotheses rely solely on algorithms that only consider incomplete lineage sorting (ILS) as a cause of intra- or intergenomic discordance. Here, we utilize a variety of methods, including those to infer phylogenetic networks, to account for both ILS and introgression as a cause for nuclear and cytoplasmic-nuclear discordance using phylogenomic data from the recently radiated flowering plant genus Polemonium (Polemoniaceae), an ecologically diverse genus in Western North America with known and suspected gene flow between species. We find evidence for widespread discordance among nuclear loci that can be explained by both ILS and reticulate evolution in the evolutionary history of Polemonium. Furthermore, the histories of organellar genomes show strong discordance with the inferred species tree from the nuclear genome. Discordance between the nuclear and plastid genome is not completely explained by ILS, and only one case of discordance is explained by detected introgression events. Our results suggest that multiple processes have been involved in the evolutionary history of Polemonium and that the plastid genome does not accurately reflect species relationships. We discuss several potential causes for this cytoplasmic-nuclear discordance, which emerging evidence suggests is more widespread across the Tree of Life than previously thought. [Cyto-nuclear discordance, genomic discordance, phylogenetic networks, plastid capture, Polemoniaceae, Polemonium, reticulations.] 

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3. Geogenomic Predictors of Genetree Heterogeneity Explain Phylogeographic and Introgression History: A Case Study in an Amazonian Bird ( Thamnophilus aethiops )

   https://doi.org/10.1093/sysbio/syad061  

   Musher, Lukas_J; Del-Rio, Glaucia; Marcondes, Rafael_S; Brumfield, Robb_T; Bravo, Gustavo_A; Thom, Gregory; Burbrink, ed., Frank (October 2023, Systematic Biology)

   Abstract Can knowledge about genome architecture inform biogeographic and phylogenetic inference? Selection, drift, recombination, and gene flow interact to produce a genomic landscape of divergence wherein patterns of differentiation and genealogy vary nonrandomly across the genomes of diverging populations. For instance, genealogical patterns that arise due to gene flow should be more likely to occur on smaller chromosomes, which experience high recombination, whereas those tracking histories of geographic isolation (reduced gene flow caused by a barrier) and divergence should be more likely to occur on larger and sex chromosomes. In Amazonia, populations of many bird species diverge and introgress across rivers, resulting in reticulated genomic signals. Herein, we used reduced representation genomic data to disentangle the evolutionary history of 4 populations of an Amazonian antbird, Thamnophilus aethiops, whose biogeographic history was associated with the dynamic evolution of the Madeira River Basin. Specifically, we evaluate whether a large river capture event ca. 200 Ka, gave rise to reticulated genealogies in the genome by making spatially explicit predictions about isolation and gene flow based on knowledge about genomic processes. We first estimated chromosome-level phylogenies and recovered 2 primary topologies across the genome. The first topology (T1) was most consistent with predictions about population divergence and was recovered for the Z-chromosome. The second (T2), was consistent with predictions about gene flow upon secondary contact. To evaluate support for these topologies, we trained a convolutional neural network to classify our data into alternative diversification models and estimate demographic parameters. The best-fit model was concordant with T1 and included gene flow between non-sister taxa. Finally, we modeled levels of divergence and introgression as functions of chromosome length and found that smaller chromosomes experienced higher gene flow. Given that (1) genetrees supporting T2 were more likely to occur on smaller chromosomes and (2) we found lower levels of introgression on larger chromosomes (and especially the Z-chromosome), we argue that T1 represents the history of population divergence across rivers and T2 the history of secondary contact due to barrier loss. Our results suggest that a significant portion of genomic heterogeneity arises due to extrinsic biogeographic processes such as river capture interacting with intrinsic processes associated with genome architecture. Future phylogeographic studies would benefit from accounting for genomic processes, as different parts of the genome reveal contrasting, albeit complementary histories, all of which are relevant for disentangling the intricate geogenomic mechanisms of biotic diversification. [Amazonia; biogeography; demographic modeling; gene flow; gene tree; genome architecture; geogenomics; introgression; linked selection; neural network; phylogenomic; phylogeography; reproductive isolation; speciation; species tree.] 

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4. A phylogenomic perspective on interspecific competition

   https://doi.org/10.1111/ele.14359  

   Louw, Nicolas L.; Wolfe, Benjamin E.; Uricchio, Lawrence H. (February 2024, Ecology Letters)

   Abstract Evolutionary processes may have substantial impacts on community assembly, but evidence for phylogenetic relatedness as a determinant of interspecific interaction strength remains mixed. In this perspective, we consider a possible role for discordance between gene trees and species trees in the interpretation of phylogenetic signal in studies of community ecology. Modern genomic data show that the evolutionary histories of many taxa are better described by a patchwork of histories that vary along the genome rather than a single species tree. If a subset of genomic loci harbour trait‐related genetic variation, then the phylogeny at these loci may be more informative of interspecific trait differences than the genome background. We develop a simple method to detect loci harbouring phylogenetic signal and demonstrate its application through a proof‐of‐principle analysis ofPenicilliumgenomes and pairwise interaction strength. Our results show that phylogenetic signal that may be masked genome‐wide could be detectable using phylogenomic techniques and may provide a window into the genetic basis for interspecific interactions. 

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5. Investigating the Genomic Distribution of Phylogenetic Signal with CloudForest

   https://doi.org/10.1145/3437359.3465605  

   Wagner, Reid; Toups, Benjamin S.; Deng, Zhifeng; Gallivan, Kyle A.; Brown, Jeremy M.; Wilgenbusch, James C. (July 2021, Proceedings of the Practice and Experience on Advanced Research Computing)

   A central focus of evolutionary biology is inferring the historical relationships among species and using this context to learn about how evolution has shaped diverse organisms. These historical relationships are represented by phylogenetic trees, and the methods used to infer these trees have been an active area of research for several decades. Despite this attention, phylogenetic workflows have changed little, even though extraordinary advances have occurred in the scale and pace at which genomic data have been collected in the past 20 years. Modern phylogenomic datasets have also raised fascinating new questions. Why do different parts of a genome often support different relationships among species? How are these different signals distributed across chromosomes? We developed a new computational framework, CloudForest, to tackle such questions. CloudForest is flexible, efficient, and tightly integrates a diverse set of tools. Here, we briefly describe the architecture of CloudForest, including the advantages it provides, and use it to investigate the distribution of phylogenetic signal along the entire X chromosome of 24 cat (Felidae) species. 

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