Genomic SNPs resolve the phylogeny of an ancient amphibian island radiation from the Seychelles.

Unusually for oceanic islands, the granitic Seychelles host multiple lineages of endemic amphibians. This includes an ancient (likely ca. 60 million years) radiation of eight caecilian species, most of which occur on multiple islands.These caecilians have a complicated taxonomic history and their phylogenetic inter-species relationships have been difficult to resolve. Double-digest RAD sequencing (ddRADseq) has been applied extensively to phylogeography and increasingly to phylogenetics but its utility for resolving ancient divergences is less well established. To address this, we applied ddRADseq to generate a genome-wide SNP panel for phylogenomic analyses of the Seychelles caecilians, whose phylogeny has so far not been satisfactorily resolved with traditional DNA markers. Based on 129,154 SNPs, we resolved deep and shallow splits, with strong support. Our findings demonstrate the capability of genome-wide SNPs for evolutionary inference at multiple taxonomic levels and support the recently proposed synonymy of Grandisonia Taylor, 1968 with Hypogeophis Peters, 1879. We revealed three clades of Hypogeophis (large-, medium- and short-bodied) and identify a single origin of the diminutive, stocky-bodied and pointy-snouted phenotype.

The state of the art-psoriatic arthritis outcome assessment in clinical trials and daily practice.

Psoriatic arthritis is a heterogeneous condition with substantial challenges in optimising outcome measures for both clinical trials and daily practice. As with other inflammatory arthritides, there is no gold standard instrument for measuring disease activity or impact, both of which are key to evaluate therapeutic approaches in trials and monitor disease in daily practice. A wide range of domains have been highlighted in the Outcome Measures in Rheumatology (OMERACT) core domain set for psoriatic arthritis; reflecting the disease involvement in multiple tissues (joints, tendons, skin, and spine) and the heterogenous impact of the disease on individuals. This Review summarises the current evidence around outcome measure selection, considering factors such as unidimensional versus multidimensional outcomes, continuous versus binary measures, and the feasibility of these approaches in trials compared with clinical practice.