Epigenetic dental variability of Israeli hares (Lepus sp.): ecogenetic or phylogenetic causation?

We examined 3747 teeth from 134 hares (Lepus sp.)(1) collected at 46 sites in Israel to test whether variation in epigenetic occlusal characters was l inked to ecogenetic or phylogenetic factors. Collection sites encompassed a wide range of ecogeographical and climatic regimes. We compared data from Israeli hares with occlusal characters of 160 cape hares L. capensis from E ast Africa and 68 brown hares L. europaeus from central Europe. Only three teeth (I-1, I-2, M-3) did not show occlusal variation. Thirty-eight occlusa l characters were derived from dental variants by dichotomous (0/1) scoring . Absence of association of character states among characters of single tee th indicated a lack of morphotypes. Epigenetic differentiation among hares from northern, central and southern Israel, and the two East African, and t wo central European samples, was revealed by pairwise C. A. B. Smith's 'mea n measures of divergence' (MMD), based on frequencies of character states. Cluster analyses of MMD values revealed little epigenetic differentiation b etween northern and southern Israeli hares, but greater differentiation bet ween central European and East African hares. Concordance of the MMD matrix with linear geographical distances among sampling regions was demonstrated by a Mantel test. No frequencies of character states exhibited significant changes across the climatic parameters among hares from northern and south ern Israel. But the individual folding index, which expresses the degree of enamel on the occlusal surface, slightly decreased from north to south. Ou r results support a phylogenetic interpretation of occlusal character varia tion. Despite distinct differences in external appearance, hares from north ern and southern Israel probably comprise a single species that encompasses two closely related geographical populations with a probable area of overl ap. Israeli hares are intermediate between European brown hares and East Af rican cape hares, with a slightly closer relationship to the cape hares.