The west European subspecies of house mouse (Mus musculus domesticus) has gained much of its current widespread distribution through commensalism with humans. This means that the phylogeography of M. m. domesticus should reflect patterns of human movements. We studied restriction fragment length polymorphism (RFLP) and DNA sequence variations in mouse mitochondrial (mt) DNA throughout the British Isles (328 mice from 105 localities, including previously published data). There is a major mtDNA lineage revealed by both RFLP and sequence analyses, which is restricted to the northern and western peripheries of the British Isles, and also occurs in Norway. This distribution of the 'Orkney' lineage fits well with the sphere of influence of the Norwegian Vikings and was probably generated through inadvertent transport by them. To form viable populations, house mice would have required large human settlements such as the Norwegian Vikings founded. The other parts of the British Isles (essentially most of mainland Britain) are characterized by house mice with different mtDNA sequences, some of which are also found in Germany, and which probably reflect both Iron Age movements of people and mice and earlier development of large human settlements. MtDNA studies on house mice have the potential to reveal novel aspects of human history.

Environmental DNA (eDNA) analysis is a rapid, non-invasive, cost-efficient biodiversity monitoring tool with enormous potential to inform aquatic conservation and management. Development is ongoing, with strong commercial interest, and new uses are continually being discovered. General applications of eDNA and guidelines for best practice in freshwater systems have been established, but habitat-specific assessments are lacking. Ponds are highly diverse, yet understudied systems that could benefit from eDNA monitoring. However, eDNA applications in ponds and methodological constraints specific to these environments remain unaddressed. Following a stakeholder workshop in 2017, researchers combined knowledge and expertise to review these applications and challenges that must be addressed for the future and consistency of eDNA monitoring in ponds. The greatest challenges for pond eDNA surveys are representative sampling, eDNA capture, and potential PCR inhibition. We provide recommendations for sampling, eDNA capture, inhibition testing, and laboratory practice, which should aid new and ongoing eDNA projects in ponds. If implemented, these recommendations will contribute towards an eventual broad standardisation of eDNA research and practice, with room to tailor workflows for optimal analysis and

The western house mouse Mus musculus domesticus is a human commensal, and as such, its phylogeography relates to historical human settlement patterns and movements. We investigate the phylogeography of house mice in northern France and the British Isles (particularly Ireland and the Scottish islands) using microsatellite data and mitochondrial (mt) control region sequences from modern and museum material, placing these in a Europe-wide context. The majority of mtDNA sequences from northern France belong to a clade widespread across the British mainland and Germany, supporting an earlier suggestion that this clade distribution represents colonization by house mice in the Iron Age. The presence of the clade in south-western Ireland indicates possible Iron Age colonization there as well. However, the majority of the Irish sequences belong to a clade elsewhere associated with Norwegian Viking activity, and likely represent the main wave of house mouse colonization of Ireland, arriving from the Scottish islands during the Viking period and linked to urbanization. The St Kilda sequences (from 100-yearold museum samples of the extinct form 'Mus muralis' of Barrett-Hamilton) and sequences from South Uist and Lewis also belong to this clade. The clustering of populations shown by the microsatellite data is distinctly different from the mtDNA phylogeny, with populations grouping by geographic proximity, possibly reflecting the genetic effects of secondary colonization. When the mtDNA sequence data are placed in a Europe-wide context, it is clear that the distributions of the two prevalent clades from the vicinity of the British Isles are essentially limited to north-western Europe. These two clades show no evidence of expansion through central Europe, and may therefore reflect maritime colonization.

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