The researchers from Laboratory of molecular bases of embryogenesis recently hypothesised that the decrease of limb regeneration capacity in amniotes (reptiles, birds and mammals) could be caused by elimination in evolution of genes, encoding for important regulators of specific wound epithelium and blastema organization, which are used by excellent regenerating anamniotes (fish and amphibia). Using two anamniotic model organisms Danio rerio adult fishes and Xenopus laevis tadpoles the authors have shown the essential role of Ras-dva small GTPases in regulation of these processes, meanwhile their genes are eliminated in a stepwise manner during evolution till total absence in placental mammals. The obtained results support the hypothesis. The investigation is published in Scientific reports.