Studies on the Unisexual Reptiles by and since I.S. Darevsky

Reproduction without males is common among various animal taxa; however, it is rarely encountered in vertebrates. The discovery of obligate parthenogenesis, which does not require the participation of males for reproduction, by Ilya Sergeevich Darevsky, has contributed significantly to the development of evolutionary biology. In the middle of the last century, I.S. Darevsky and his colleagues defined the main directions of research on this phenomenon, thanks to which unisexual species of rock and whiptail lizards, geckos, and skinks became the focus of attention for biologists studying the fundamental questions of species evolution. The pioneers of parthenogenesis in vertebrates have made significant progress in these studies; however, methodological approaches that have emerged in recent years allow answering the questions related to the origin and evolution of unisexual vertebrates. In this review, we present the achievements and results in each direction of research conducted by I.S. Darevsky and his colleagues. In addition, we outline new ideas and mention the latest discoveries in the field of research on unisexual reptile species made after I.S. Darevsky had passed. In the concluding part of the work, we outline a range of tasks that require solutions in the future.