Fig. 1
From: Wide-scale identification of novel/eliminated genes responsible for evolutionary transformations
Declining capability to regenerate large body appendages, i.e., limbs and tail, in the line of vertebrates from fish and amphibians to placental mammals. Shown are groups of vertebrates that emerged sequentially in evolution. Some extant species from these groups were collected into the lower, middle, and upper species sets to search for genes absent in reptiles, birds, and mammals but involved in tadpole tail regeneration in Xenopus tropicalis, which was chosen as the reference species R (see main text for details)