From Geographic Parthenogenesis to Reticulate (Hybridogenous) Speciation: I.S. Darevsky (1924–2009), Rock Lizards of the Caucasus, and the Problem of Clonal Evolution

The path taken by I.S. Darevsky to the discovery of natural parthenogenesis in rock lizards of the Caucasus (1957, 1958) is tracked, and his further developments of the problem of parthenogenesis in lizards in his main papers (1962, 1966, 1967) and monograph (1967) are discussed. The following issues are considered: geographic and hybrid parthenogenesis, subspecies and species in unisexual lizards, spontaneous males in parthenogenetic species, the essence of I.S. Darevsky’s discovery in the context of different categories of clonal reproduction in animals, the formation of the concept of reticular speciation, and the evolutionary age of clonal forms in various groups of animals.