Population genetic structure of the highly endangered butterfly Coenonympha oedippus (Nymphalidae: Satyrinae) at its southern edge of distribution.

The Slovenian False Ringlet Coenonympha oedippus populations are under serious threat, as in the last two decades have witnessed a sharp decline in population distribution and size due to destruction, fragmentation and/or habitat quality degradation through intensive agriculture, abandonment of use and urbanization. We investigated the genetic diversity and structure of C. oedippus from the entire range of the species in Slovenia. Our results showed that the genetic variation in the Slovenian C. oedippus populations agrees with the geographical structure and the ecotypes previously determined by morphological and ecological data. We confirmed the existence of four genetically divergent and spatially non-overlapping geographical groups (Istria, Karst, Gorica, Ljubljansko barje) and two ecotypes ("wet" and "dry"). Despite small sample sizes due to critically threatened species, the results indicated significant nuclear and mitochondrial genetic diversity within the spatial groups. By gaining new insights into the evolutionary history of the C. oedippus population, we have recommended to consider the Slovenian population as one Evolutionary Significant Unit, and four spatial populations as Management Units for conservation purposes.

Fundamental research questions in subterranean biology.

Five decades ago, a landmark paper in Science titled The Cave Environment heralded caves as ideal natural experimental laboratories in which to develop and address general questions in geology, ecology, biogeography, and evolutionary biology. Although the 'caves as laboratory' paradigm has since been advocated by subterranean biologists, there are few examples of studies that successfully translated their results into general principles. The contemporary era of big data, modelling tools, and revolutionary advances in genetics and (meta)genomics provides an opportunity to revisit unresolved questions and challenges, as well as examine promising new avenues of research in subterranean biology. Accordingly, we have developed a roadmap to guide future research endeavours in subterranean biology by adapting a well-established methodology of 'horizon scanning' to identify the highest priority research questions across six subject areas. Based on the expert opinion of 30 scientists from around the globe with complementary expertise and of different academic ages, we assembled an initial list of 258 fundamental questions concentrating on macroecology and microbial ecology, adaptation, evolution, and conservation. Subsequently, through online surveys, 130 subterranean biologists with various backgrounds assisted us in reducing our list to 50 top-priority questions. These research questions are broad in scope and ready to be addressed in the next decade. We believe this exercise will stimulate research towards a deeper understanding of subterranean biology and foster hypothesis-driven studies likely to resonate broadly from the traditional boundaries of this field.