When interpreting genetic patterns across a landscape it is surprisingly difficult to disentangle the effects of landscape connectivity from those of species biology. Here, the spatial distributions of genetic variation of two sympatric elephant-shrew species, the western rock elephant-shrew (Elephantulus rupestris) and the round-eared elephant-shrew (Macroscelides proboscideus), are determined and compared. We selected these species because they have similar biologies but differ markedly in habitat use, the rationale being that differences in their genetic structure should be a result largely of landscape variables directly or indirectly affecting dispersal rather than of the biology of the species. Keywords: Elephant-shrews, Elephantulus rupestris, isolation-by-distance, Macroscelidea, Macroscelides proboscideus, mammals, Namibia, phylogeography, sengi, South Africa.