No abstract

Mechanisms of survival during the Pleistocene glaciation periods have been studied for more than a century. Until now, molecular studies that confirmed animal survival on Alpine nunataks, that is, ice-free summits surrounded by glaciers, were restricted to peripheral areas. Here, we search for molecular signatures of inner-Alpine survival of the narrow endemic and putatively parthenogenetic Alpine jumping bristletail Machilis pallida combining mitochondrial and AFLP data from its three known populations. The mitochondrial data indicate survival on both peripheral and central nunataks, the latter suggesting that refugia in the centre of the Alpine main ridge were more widespread than previously recognized. Incongruences between mitochondrial and AFLP patterns suggest a complex evolutionary history of the species and may be explained via parallel fixation of parthenogenesis of different origins during the last glacial maximum. We suggest that the inferred parthenogenesis may have been essential for central nunatak survival, but may pose a serious threat for M. pallida in consideration of the present climatic changes.

Endemic species play an important role in conservation ecology. However, knowledge of the real distribution and ecology is still scarce for many endemics. The aims of this study were to predict the distribution of the short-range endemic Alpine jumping bristletail Machilis pallida; to evaluate the actual level of endemism via ground validation using an iterative approach for testing the models in field trips and increasing the quality of the prediction step by step; and to test the potential of species distribution modelling for increasing the knowledge about the ecological niche. Based on seven known locations of M. pallida, we used species distribution modelling via Maxent. After a set of seven field trips a new model was built if new locations were found. Three such iterations were performed to increase model quality. We discovered four new locations of M. pallida, increasing the area of known distribution from 470 to 4,890 km 2 . The distribution of M. pallida is thus wider than formerly known, but our results support Eastern Alpine endemism of the species. The knowledge about the ecological niche could be increased due to the newly found locations. Our study showcases the potential of the iterative approach of modelling and ground validation to evaluate the actual level of endemism and the ecological niche in Alpine species and beyond.