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Creators/Authors contains: "Chakrabarty, Prosanta"

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  1. Synopsis Basic science research, also called “curiosity-driven research,” is fundamental work done with no immediate economic goals but rather a focus on discovery for discovery’s sake. However, basic science research is often needed to seed more applied, economically oriented, research. Both basic and applied research efforts are important aspects of the “bioeconomy,” defined here as the contributions to the overall economy from various biology-related fields spanning everything from museum-based natural history research to agricultural food and material production to healthcare. Here, we propose that more collaborative efforts across federal granting agencies in a venture-capitalist-like “PO-driven model” can help drive applied innovation from collaborations facilitated by program officers (POs). POs from NSF, DOE, DARPA, USDA, NASA, and other federal agencies should seek out parallel and complementary research ideas from grantees and provide funds to build teams of researchers who may otherwise be unaware of one another. Researchers working in different fields may also be unaware that the different organisms they are studying independently may have evolved similar traits (i.e., convergent evolution) that POs may recognize and who can then facilitate novel research avenues connecting those independent researchers (we provide examples of some projects inspired by convergent evolution here). In this top-down approach to research funding, the US bioeconomy will be pouring fuel on the fire of scientific productivity in this country. 
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  2. Cave-obligate aquatic organisms are difficult to monitor for conservation due to cryptic diversity, unknown subterranean hydrological connectivity, and accessibility to habitats. Conservation management practices have benefitted from evolutionary data; however, the evolutionary and biogeographic histories of most cave-obligate organisms are unknown. The modes and patterns leading to most cave-obligate organism distributions are also uncertain. The Southern Cavefish (Typhlichthys subterraneus, Amblyopsidae) is the largest ranging cavefish in the world but represents a species complex of which the distribution and relatedness within remains unclear. To explore modes of cave-adaptive evolution, we performed population genomic analyses on a dataset of single nucleotide polymorphisms harvested from ultraconserved elements. We found five to eight strongly delineated genetic clusters. Little to no genetic exchange occurred between clusters, indicating high genetic distinctiveness and low connectivity, a concerning result for the fitness and conservation of these fishes. Genetic clusters did not correspond to caves nor to other geographic boundaries examined. Unfortunately, one of the geographic units most easily communicated for conservation– caves– do not match the biological units of interest. Our results support multiple independent colonization events from a widespread surface ancestor with a small degree of cave connectivity among, but not between, clusters. We suggest whole cave system conservation. 
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  3. null (Ed.)
    A voucher is a permanently preserved specimen that is maintained in an accessible collection. In genomics, vouchers serve as the physical evidence for the taxonomic identification of genome assemblies. Unfortunately, the vast majority of vertebrate genomes stored in the GenBank database do not refer to voucher specimens. Here, we urge researchers generating new genome assemblies to deposit voucher specimens in accessible, permanent research collections, and to link these vouchers to publications, public databases, and repositories. We also encourage scientists to deposit voucher specimens in order to recognize the work of local field biologists and promote a diverse and inclusive knowledge base, and we recommend best practices for voucher deposition to prevent taxonomic errors and ensure reproducibility and legality in genetic studies. 
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  4. ABSTRACT Balitorid loaches are a family of fishes that exhibit morphological adaptations to living in fast flowing water, including an enlarged sacral rib that creates a ‘hip’-like skeletal connection between the pelvis and the axial skeleton. The presence of this sacral rib, the robustness of which varies across the family, is hypothesized to facilitate terrestrial locomotion seen in the family. Terrestrial locomotion in balitorids is unlike that of any known fish: the locomotion resembles that of terrestrial tetrapods. Emergence and convergence of terrestrial locomotion from water to land has been studied in fossils; however, studying balitorid walking provides a present-day natural laboratory to examine the convergent evolution of walking movements. We tested the hypothesis that balitorid species with more robust connections between the pelvic and axial skeleton (M3 morphotype) are more effective at walking than species with reduced connectivity (M1 morphotype). We predicted that robust connections would facilitate travel per step and increase mass support during movement. We collected high-speed video of walking in seven balitorid species to analyze kinematic variables. The connection between internal anatomy and locomotion on land are revealed herein with digitized video analysis, μCT scans, and in the context of the phylogenetic history of this family of fishes. Our species sampling covered the extremes of previously identified sacral rib morphotypes, M1 and M3. Although we hypothesized the robustness of the sacral rib to have a strong influence on walking performance, there was not a large reduction in walking ability in the species with the least modified rib (M1). Instead, walking kinematics varied between the two balitorid subfamilies with a generally more ‘walk-like’ behavior in the Balitorinae and more ‘swim-like’ behavior in the Homalopteroidinae. The type of terrestrial locomotion displayed in balitorids is unique among living fishes and aids in our understanding of the extent to which a sacral connection facilitates terrestrial walking. 
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  5. Systematic relationships within the Cirrhitoidei, a suborder of five closely related families, have been uncertain for over a century. This is particularly true in reference to the families Cheilodactylidae and Latridae, which have been revised numerous times over the past several decades. Species that have been included in these two families are found in temperate regions around the world, which has led to regionally-focused studies that have only exacerbated taxonomic confusion. Here we examine systematic relationships within the Cheilodactylidae and the Latridae using ultraconserved genomic elements with near complete taxonomic sampling, and place our results in the context of the Cirrhitoidei. Our results agree with previous findings suggesting that Cheilodactylidae is restricted to two South African species, with the type species of the family, Cheilodactylus fasciatus Lacépède, forming a clade with C. pixi Smith that together is more closely related to the Chironemidae than to other species historically associated with the genus. We also strongly resolve the relationships of species within the Latridae. As a result of our analyses we revise the taxonomy of Latridae, name a new genus, and re-elevate Chirodactylus and Morwong. 
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  6. Abstract Zoos and natural history museums are both collections-based institutions with important missions in biodiversity research and education. Animals in zoos are a repository and living record of the world's biodiversity, whereas natural history museums are a permanent historical record of snapshots of biodiversity in time. Surprisingly, despite significant overlap in institutional missions, formal partnerships between these institution types are infrequent. Life history information, pedigrees, and medical records maintained at zoos should be seen as complementary to historical records of morphology, genetics, and distribution kept at museums. Through examining both institution types, we synthesize the benefits and challenges of cross-institutional exchanges and propose actions to increase the dialog between zoos and museums. With a growing recognition of the importance of collections to the advancement of scientific research and discovery, a transformational impact could be made with long-term investments in connecting the institutions that are caretakers of living and preserved animals. 
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  7. Abstract The rheophilic hillstream loaches (Balitoridae) of South and Southeast Asia possess a range of pelvic girdle morphologies, which may be attributed to adaptations for locomotion against rapidly flowing water. Specifically, the connectivity of the pelvic plate (basipterygium) to the vertebral column via a sacral rib, and the relative size and shape of the sacral rib, fall within a spectrum of three discrete morphotypes: long, narrow rib that meets the basipterygium; thicker, slightly curved rib meeting the basipterygium; and robust crested rib interlocking with the basipterygium. Species in this third category with more robust sacral rib connections between the basipterygium and vertebral column are capable of walking out of water with a tetrapod‐like lateral‐sequence, diagonal‐couplet gait. This behavior has not been observed in species lacking direct skeletal connection between the vertebrae and the pelvis. The phylogenetic positions of the morphotypes were visualized by matching the morphological features onto a novel hypothesis of relationships for the family Balitoridae. The morphotypes determined through skeletal morphology were correlated with patterns observed in the pelvic muscle morphology of these fishes. Transitions towards increasingly robust pelvic girdle attachment were coincident with a more anterior origin on the basipterygium and more lateral insertion of the muscles on the fin rays, along with a reduction of the superficial abductors and adductors with more posterior insertions. These modifications are expected to provide a mechanical advantage for generating force against the ground. Inclusion of the enigmatic cave‐adapted balitoridCryptotora thamicolainto the most data‐rich balitorid phylogeny reveals its closest relatives, providing insight into the origin of the skeletal connection between the axial skeleton and basipterygium. 
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  8. Abstract A wide variety of species are distinguished by slight color variations. However, molecular analyses have repeatedly demonstrated that coloration does not always correspond to distinct evolutionary histories between closely related groups, suggesting that this trait is labile and can be misleading for species identification. In the present study, we analyze the evolutionary history of sister species ofPrionurussurgeonfishes in the Tropical Eastern Pacific (TEP), which are distinguished by the presence or absence of dark spots on their body. We examined the species limits in this system using comparative specimen‐based approaches, a mitochondrial gene (COI), more than 800 nuclear loci (Ultraconserved Elements), and abiotic niche comparisons. The results indicate there is a complete overlap of meristic counts and morphometric measurements between the two species. Further, we detected multiple individuals with intermediate spotting patterns suggesting that coloration is not diagnostic. Mitochondrial data recovered a single main haplotype shared between the species and all locations resulting in a complete lack of structure (ΦST = 0). Genomic analyses also suggest low levels of genetic differentiation (FST = 0.013), and no alternatively fixed SNPs were detected between the two phenotypes. Furthermore, niche comparisons could not reject niche equivalency or similarity between the species. These results suggest that these two phenotypes are conspecific and widely distributed in the TEP. Here, we recognizePrionurus punctatusGill 1862 as a junior subjective synonym ofP. laticlavius(Valenciennes 1846). The underlying causes of phenotypic variation in this species are unknown. However, this system gives insight into general evolutionary dynamics within the TEP. 
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