Body size is an important species trait, correlating with life span, fecundity, and other ecological factors. Over Earth’s geological history, climate shifts have occurred, potentially shaping body size evolution in many clades. General rules attempting to summarize body size evolution include Bergmann’s rule, which states that species reach larger sizes in cooler environments and smaller sizes in warmer environments, and Cope’s rule, which poses that lineages tend to increase in size over evolutionary time. Tetraodontiform fishes (including pufferfishes, boxfishes, and ocean sunfishes) provide an extraordinary clade to test these rules in ectotherms owing to their exemplary fossil record and the great disparity in body size observed among extant and fossil species. We examined Bergmann’s and Cope’s rules in this group by combining phylogenomic data (1,103 exon loci from 185 extant species) with 210 anatomical characters coded from both fossil and extant species. We aggregated data layers on paleoclimate and body size from the species examined, and inferred a set of time-calibrated phylogenies using tip-dating approaches for downstream comparative analyses of body size evolution by implementing models that incorporate paleoclimatic information. We found strong support for a temperature-driven model in which increasing body size over time is correlated with decreasing oceanic temperatures. On average, extant tetraodontiforms are two to three times larger than their fossil counterparts, which otherwise evolved during periods of warmer ocean temperatures. These results provide strong support for both Bergmann’s and Cope’s rules, trends that are less studied in marine fishes compared to terrestrial vertebrates and marine invertebrates.

Convolvulaceae is a family of c. 2,000 species, distributed across 60 currently recognized genera. It includes species of high economic importance, such as the crop sweet potato ( Ipomoea batatas L.), the ornamental morning glories ( Ipomoea L.), bindweeds ( Convolvulus L.), and dodders, the parasitic vines ( Cuscuta L.). Earlier phylogenetic studies, based predominantly on chloroplast markers or a single nuclear region, have provided a framework for systematic studies of the family, but uncertainty remains at the level of the relationships among subfamilies, tribes, and genera, hindering evolutionary inferences and taxonomic advances. One of the enduring enigmas has been the relationship of Cuscuta to the rest of Convolvulaceae. Other examples of unresolved issues include the monophyly and relationships within Merremieae, the “bifid-style” clade (Dicranostyloideae), as well as the relative positions of Erycibe Roxb. and Cardiochlamyeae. In this study, we explore a large dataset of nuclear genes generated using Angiosperms353 kit, as a contribution to resolving some of these remaining phylogenetic uncertainties within Convolvulaceae. For the first time, a strongly supported backbone of the family is provided. Cuscuta is confirmed to belong within family Convolvulaceae. “Merremieae,” in their former tribal circumscription, are recovered as non-monophyletic, with the unexpected placement of Distimake Raf. as sister to the clade that contains Ipomoeeae and Decalobanthus Ooststr., and Convolvuleae nested within the remaining “Merremieae.” The monophyly of Dicranostyloideae, including Jacquemontia Choisy, is strongly supported, albeit novel relationships between genera are hypothesized, challenging the current tribal delimitation. The exact placements of Erycibe and Cuscuta remain uncertain, requiring further investigation. Our study explores the benefits and limitations of increasing sequence data in resolving higher-level relationships within Convolvulaceae, and highlights the need for expanded taxonomic sampling, to facilitate a much-needed revised classification of the family.

Southern East Asia is the dispersal center regarding the prehistoric settlement and migrations of modern humans in Asia-Pacific regions. However, the settlement pattern and population structure of paleolithic humans in this region remain elusive, and ancient DNA can provide direct information. Here, we sequenced the genome of a Late Pleistocene hominin (MZR), dated ∼14.0 thousand years ago from Red Deer Cave located in Southwest China, which was previously reported possessing mosaic features of modern and archaic hominins. MZR is the first Late Pleistocene genome from southern East Asia. Our results indicate that MZR is a modern human who represents an early diversified lineage in East Asia. The mtDNA of MZR belongs to an extinct basal lineage of the M9 haplogroup, reflecting a rich matrilineal diversity in southern East Asia during the Late Pleistocene. Combined with the published data, we detected clear genetic stratification in ancient southern populations of East/Southeast Asia and some degree of south-versus-north divergency during the Late Pleistocene, and MZR was identified as a southern East Asian who exhibits genetic continuity to present day populations. Markedly, MZR is linked deeply to the East Asian ancestry that contributed to First Americans.

The global market of the medicinal plant ginseng is worth billions of dollars. Many ginseng species are threatened in the wild and effective sustainable development initiatives are necessary to preserve biodiversity at species and genetic level whilst meeting the demand for medicinal produce. This is also the case of Panax vietnamensis Ha & Grushv., an endemic and threatened ginseng species in Vietnam that is locally cultivated at different scales and has been the object of national breeding programs. To investigate the genetic diversity within cultivated and wild populations of P. vietnamensis we captured 353 nuclear markers using the Angiosperm-353 probe set. Genetic diversity and population structure were evaluated for 319 individuals of Vietnamese ginseng across its area of distribution and from wild and a varying range of cultivated areas. In total, 319 individuals were sampled. After filtering, 1,181 SNPs were recovered. From the population statistics, we observe high genetic diversity and high genetic flow between populations. This is also supported by the STRUCTURE analysis. The intense gene flow between populations and very low genetic differentiation is observed regardless of the populations’ wild or cultivated status. High levels of admixture from two ancestral populations exist in both wild and cultivated samples. The high gene flow between populations can be attributed to ancient and on-going practices of cultivation, which exist in a continuum from understorey, untended breeding to irrigated farm cultivation and to trade and exchange activities. These results highlight the importance of partnering with indigenous peoples and local communities and taking their knowledge into account for biodiversity conservation and sustainable development of plants of high cultural value.

The generic placement of the enigmatic and extinct Logania depressa from New Zealand has been uncertain due to the paucity of available plant material. This diminutive plant has only been collected once from the central North Island, New Zealand, by William Colenso on 22 February 1847. Logania depressa is dioecious and the single collection comprises only male flowers and does not include female flowers or fruit that feature generic diagnostic characters. Previously its relationship to Geniostoma has been considered and its affinities to Orianthera are unknown. Orianthera has been recently recognised as a segregate of Logania. Using leaf material from a small fragment of L. depressa held in Allan Herbarium (CHR) we recovered 9,368 bp of plastid sequence data that mapped to Mitreola yangchuensis, with Mitreola being the closest generic relative of Logania for which whole genome data was available. Available genetic data for Loganiaceae is limited to several chloroplast markers, including the rps16 intron, petD intron, and petD–petB intergenic spacer. From the novel plastid sequence data for Logania depressa, 48 bp of the rps16 intron, 45 bp of the petD intron and 49 bp of the petD–petB intergenic spacer could be recovered to compare with available Loganiaceae sequences. Phylogenetic analysis of these sequences confirmed L. depressa as the only New Zealand member of Logania sens. str., but its relationships to Australian species are unresolved.

Abstract Connectivity among wildlife populations facilitates exchange of genetic material between groups. Changes to historical connectivity patterns resulting from anthropogenic activities can therefore have negative consequences for genetic diversity, particularly for small or isolated populations. DNA obtained from museum specimens can enable direct comparison of temporal changes in connectivity among populations, which can aid in conservation planning and contribute to understanding of population declines. However, museum DNA can be degraded and only available in low quantities, rendering it challenging for use in population genomic analyses. Applications of genomic methodologies such as targeted sequencing address this issue by enabling capture of shared variable sites, increasing quantity and quality of recovered genomic information. We used targeted sequencing of Ultra-conserved Elements (UCEs) to evaluate potential changes in connectivity and genetic diversity of roseate terns (Sterna dougallii) with a breeding distribution in the Northwestern Atlantic and the Caribbean. Both populations experienced range contractions and population declines due to anthropogenic activity in the 20th century, which has the potential to alter historical connectivity regimes. Instead, we found that the two populations were differentiated historically as well as contemporaneously, with little evidence of migration between them for either time period. We also found no evidence for temporal changes in genetic diversity, although these interpretations may have been limited due to sequencing artifacts caused by the degraded nature of the museum samples. Population structuring in migratory seabirds is typically reflective of low rates of divergence and high connectivity among geographically segregated subpopulations. Our contrasting results suggest the potential presence of ecological mechanisms driving population differentiation, and highlight the value of targeted sequencing on DNA derived from museum specimens to uncover long-term patterns of genetic differentiation in wildlife populations.

Increased plasma mitochondrial DNA concentrations are associated with poor outcomes in multiple critical illnesses, including COVID-19. However, current methods of cell-free mitochondrial DNA quantification in plasma are time-consuming and lack reproducibility. Here, we used next-generation sequencing to characterize the size and genome location of circulating mitochondrial DNA in critically ill subjects with COVID-19 to develop a facile and optimal method of quantification by droplet digital PCR. Sequencing revealed a large percentage of small mitochondrial DNA fragments in plasma with wide variability in coverage by genome location. We identified probes for the mitochondrial DNA genes, cytochrome B and NADH dehydrogenase 1, in regions of relatively high coverage that target small sequences potentially missed by other methods. Serial assessments of absolute mitochondrial DNA concentrations were then determined in plasma from 20 critically ill subjects with COVID-19 without a DNA isolation step. Mitochondrial DNA concentrations on the day of enrollment were increased significantly in patients with moderate or severe acute respiratory distress syndrome (ARDS) compared with those with no or mild ARDS. Comparisons of mitochondrial DNA concentrations over time between patients with no/mild ARDS who survived, patients with moderate/severe ARDS who survived, and nonsurvivors showed the highest concentrations in patients with more severe disease. Absolute mitochondrial DNA quantification by droplet digital PCR is time-efficient and reproducible; thus, we provide a valuable tool and rationale for future studies evaluating mitochondrial DNA as a real-time biomarker to guide clinical decision-making in critically ill subjects with COVID-19.