Figure 1

Study system. A) Geographical distribution of the species used in the experiments and B) phylogenetic relationships among them (modified from ref. [20]). Yellow background areas in the map, distribution of the limestone. Coloured circles, caves known to have the species; with a star, the cave from which the studied specimens were collected (M. infernus and T. arcticollis are only known from a reduced number of caves in close proximity, and their ranges are represented by a single circle). Numbers in the nodes, millions of years before present. Photo habitus, Troglocharinus ferreri.