Jigmidmaa Boldbaatar

1 INTRODUCTION In the wild, parthenogenetic and closely related sexual species often show a pattern of differing reproductive modes over a geographic landscape, a phenomenon known as geographic parthenogenesis (Vandel, 1928; Lynch, 1984). The pattern of geographical parthenogenesis is highly variable. In some taxa, sexuals and parthenogens are clearly separated along climatic or ecological gradients.

Abstract Closely related sexual and parthenogenetic species often show distinct distribution patterns, known as geographical parthenogenesis. These patterns, characterized by a mosaic of separate sexual and parthenogenetic populations across their natural range, can also be found in facultative parthenogens, species in which every female is capable of both sexual and parthenogenetic reproduction. The underlying mechanisms driving this phenomenon in nature remain unclear.