Whole genome duplication plays a central role in plant evolution. There are two main classes of polyploid formation: autopolyploids which arise within one species by doubling of similar homologous genomes; in contrast, allopolyploidy (hybrid polyploidy) arise via hybridization and subsequent doubling of nonhomologous (homoeologous) genomes. The distinction between polyploid origins can be made using gene phylogenies, if alleles from each genome can be correctly retrieved. We examined whether two closely related tetraploid Mediterranean shrubs (Medicago arborea and M. strasseri) have an allopolyploid origin – a question that has remained unsolved despite substantial previous research. We sequenced and analyzed ten low-copy nuclear genes from these and related species, phasing all alleles. To test the efficacy of allele phasing on the ability to recover the evolutionary origin of polyploids, we compared these results to analyses using unphased sequences.

Here we show that the most venomous spiders in the world are phylogenetically misplaced. Australian atracine spiders (family Hexathelidae), including the notorious Sydney funnel-web spider Atrax robustus, produce venom peptides that can kill people. Intriguingly, eastern Australian mouse spiders (family Actinopodidae) are also medically dangerous, possessing venom peptides strikingly similar to Atrax hexatoxins. Based on the standing morphology-based classification, mouse spiders are hypothesized distant relatives of atracines, having diverged over 200 million years ago. Using sequence-capture phylogenomics, we instead show convincingly that hexathelids are non-monophyletic, and that atracines are sister to actinopodids. Three new mygalomorph lineages are elevated to the family level, and a revised circumscription of Hexathelidae is presented. Re-writing this phylogenetic story has major implications for how we study venom evolution in these spiders, and potentially genuine consequences for antivenom development and bite treatment research. More generally, our research provides a textbook example of the applied importance of modern phylogenomic research.

Author summary The Scandinavian peninsula was the last part of Europe to be colonized after the Last Glacial Maximum. The migration routes, cultural networks, and the genetic makeup of the first Scandinavians remain elusive and several hypotheses exist based on archaeology, climate modeling, and genetics. By analyzing the genomes of early Scandinavian hunter-gatherers, we show that their migrations followed two routes: one from the south and another from the northeast along the ice-free Norwegian Atlantic coast. These groups met and mixed in Scandinavia, creating a population more diverse than contemporaneous central and western European hunter-gatherers. As northern Europe is associated with cold and low light conditions, we investigated genomic patterns of adaptation to these conditions and genes known to be involved in skin pigmentation. We demonstrate that Mesolithic Scandinavians had higher levels of light pigmentation variants compared to the respective source populations of the migrations, suggesting adaptation to low light levels and a surprising signal of genetic continuity in TMEM131, a gene that may be involved in long-term adaptation to the cold.

Author summary Hepatitis B virus (HBV) exerts formidable morbidity and mortality in humans. We used ancient DNA techniques to recover the complete genome sequence of an HBV from the mummified remains of a child discovered in the 16th century from Naples, Italy. Strikingly, our analysis of this specimen resulted in two contrasting findings: while the damage patterns lend credence to this HBV sequence being authentically 16th century, phylogenetic analysis revealed a close relationship to recently sampled viruses as expected if the sequence were a modern contaminant. We reconcile these two observations by showing that HBV evolution over the last ~450 years is characterized by a marked lack of temporal structure that hinders attempts to resolve the evolutionary time-scale of this important human pathogen.

We sequenced the complete mitochondrial genomes of three pairs of congeneric peripheral fishes distributed on either side of the Isthmus of Panama in order to test their status as geminate species pairs. Our phylogenetic analysis did not support a sister relationship between Gobiomorus dormitor and G. maculatus and therefore they cannot be considered geminates. The average genetic distance of protein-coding genes between Sicydium altum and S. salvini was more than two times larger than between Atlantic and Pacific Awaous banana, suggesting different timings for their divergence across the Isthmus of Panama.

The high O2 affinity of European mole (Talpa europaea) blood is postulated to largely arise from the presence of two β-globin chain residues (β4 Ser and β5 Gly) that weaken the interaction of its hemoglobin (Hb) with the red cell organophosphate 2,3-diphosphoglycerate (DPG). This latter trait is generally accepted to be an ‘adaptation to subterranean life’, despite the fact that no data are available for more basal mole lineages that have no evolutionary history of fossoriality (i.e. the ambulatory, high-elevation shrew-like moles and the semi-aquatic desmans), and which may similarly benefit from an elevated blood O2 affinity. To test whether evolution of a low DPG sensitivity phenotype is linked to derived fossorial lifestyles or represents an ancestral trait for the family, we determined the globin gene sequences and measured the intrinsic O2 affinity and co-factor sensitivity of the major Hb component of the gracile shrew-like mole (Uropsilus gracilis) and the Pyrenean desman (Galemys pyrenaicus). Our results unequivocally demonstrate that the presence of β4 Ser and β5 Gly, together with a low DPG sensitivity Hb phenotype, predates the radiation of the family Talpidae, and hence did not evolve as a specific adaptation to fossorial life. By contrast, our comparative analyses suggest that variations in whole blood O2 affinity among members of this family predominantly arose from amino acid substitutions that increase or decrease the intrinsic O2 affinity of the protein.

Aim The Tasmanian tiger, or thylacine, is an infamous example of a recent human-mediated extinction. Confined to the island of Tasmania in historical times, thylacines were hunted to extinction <150 years after European arrival. Thylacines were also once widespread across the Australian mainland, but became extinct there c. 3,200 years before present (bp). Very little is known about thylacine biology and population history; the cause of the thylacines extirpation from the mainland is still debated and the reasons for its survival in Tasmania into the 20th century are unclear. In this study, we investigate the thylacine's phylogeography and demographic history leading up to their extinction on both the mainland and Tasmania to gain insight into this enigmatic species. Location Southern Australia. Methods We generated 51 new thylacine mitochondrial DNA (mtDNA) genome sequences from sub-fossil remains and historical museum specimens, and analysed them to reconstruct the species’ phylogeography and demographic history. Results We found evidence that thylacines had contracted into separate eastern and western populations prior to the Last Glacial Maximum (c. 25,000 yr bp), and that the ancient western population was larger and more genetically diverse than the historical Tasmanian population. At the time of European arrival in c. 1800 CE, Tasmanian thylacines had limited mtDNA diversity, possibly resulting from a bottleneck event broadly coincident with an El Niño-Southern Oscillation (ENSO) associated climate event, although we find some indication that the population was expanding during the late Holocene. Main Conclusions The timing of this putative expansion, in concert with a climate event, suggests that climate change had an influence on thylacine population dynamics. Given that ENSO effects are known to have been more severe on mainland Australia, we suggest that climate change, in synergy with other drivers, is likely to have contributed to the thylacine mainland extinction.

Abstract. The highlands of Mesoamerica harbour some of the highest biodiversity in the world, especially in cloud forests, but the landscape drivers of this di

We aimed to determine the diagnostic yield of a targeted-exome panel in a cohort of 74 Dutch primary ciliary dyskinesia (PCD) patients. The panel consisted of 26 PCD-related and 284 candidate genes. To prioritize PCD candidate genes, we investigated the transcriptome of human airway cells of twelve healthy volunteers during in vitro ciliogenesis and hypothesized that PCD-related genes show significant upregulation. We compared gene expression in epithelial precursor cells grown as collagen monolayer and ciliated cells grown in suspension by RNA sequencing. All genes reported as PCD causative, except NME8, showed significant upregulation during in vitro ciliogenesis. We observed 67,6% diagnostic yield when testing the targeted-exome panel in our cohort. There was relatively high percentage of DNAI and HYDIN mutations compared to other countries. The latter may be due to our solution for the problem of the confounding HYDIN2 pseudogene. Candidate genes included two recently published PCD-related genes DNAJB13 and PIH1D3; identification of the latter was a direct result of this study. In conclusion, we demonstrate 67,6% diagnostic yield by targeted exome sequencing in a Dutch PCD population and present a highly sensitive and moderately specific approach for identification of PCD-related genes, based on significant upregulation during in vitro ciliogenesis. This article is protected by copyright. All rights reserved

While genetic exchange between non-sister species was traditionally considered to be rare in mammals, analyses of molecular data in multiple systems suggest that it may be common. Interspecific gene flow, if present, is problematic for phylogenetic inference, particularly for analyses near the species level. Here, we explore how to detect and account for gene flow during phylogeny estimation using data from a clade of North American Myotis bats where previous results have led researchers to suspect that gene flow among lineages is present. Initial estimates of phylogenetic networks and species trees indicate that subspecies described within M. lucifugus are paraphyletic. In order to explore the extent to which gene flow is likely to interfere with phylogeny estimation, we use posterior predictive simulation and a novel ABC approach based on gene tree distances. The former indicates that the species tree model is a poor fit to the data, and the latter provides evidence that a species tree with gene flow is a better fit. Taken together, we present evidence that the currently recognized M. lucifugus subspecies are paraphyletic, exchange alleles with other Myotis species in regions of secondary contact, and should be considered independent evolutionary lineages despite their morphological similarity.