12 research outputs found
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Geographic Life History Differences Predict Genomic Divergence Better than Mitochondrial Barcodes or Phenotype
Species diversity can be inferred using multiple data types, however, results based on genetic data can be at odds with patterns of phenotypic variation. Tiger beetles of the Cicindelidia politula (LeConte, 1875) species complex have been taxonomically problematic due to extreme phenotypic variation within and between populations. To better understand the biology and taxonomy of this group, we used mtDNA genealogies and multilocus nuclear analyses of 34,921 SNPs to elucidate its evolutionary history and evaluate the validity of phenotypically circumscribed species and subspecies. Genetic analyses recovered two divergent species that are also ecologically distinct, based on adult life history. These patterns are incongruous with the phenotypic variation that informed prior taxonomy, and most subspecies were not supported as distinct evolutionary lineages. One of the nominal subspecies was found to be a cryptic species; consequently, we elevate C. p. laetipennis (Horn, 1913) to a full species. Although nuclear and mtDNA datasets recovered broadly similar evolutionary units, mito-nuclear discordance was more common than expected, being observed between nearly all geographically overlapping taxonomic pairs. Additionally, a pattern of ‘mitochondrial displacement’ was observed, where mitochondria from one species unidirectionally displace others. Overall, we found that geographically associated life history factors better predict genomic divergence than phenotype and mitochondrial genealogies, and consequently taxon identifications based on mtDNA (e.g., DNA barcodes) may be misleading
Innovative approaches to investigator-initiated, multicentre paediatric clinical trials in Canada
Data from clinical trials are needed to guide the safe and effective use of medicines in children. Clinical trials are challenging to design and implement in all populations, and children present additional considerations. Several regions including the UK, USA and Europe have established clinical trial infrastructure to capitalise on expertise and promote clinical trials enrolling children. Our objective is to describe the partnerships and operational considerations for the development of paediatric clinical trials infrastructure in Canada. We describe the design and conduct of four emergency room paediatric trials, with four separate sponsors, across four provinces in parallel. Operations discussed include multisite contract development, centralised risk-based data monitoring, ethical review and patient engagement. We conclude with lessons learnt, additional challenges and potential solutions to facilitate drug development for children in Canada