For all the Mammals, nature and evolution preferred scarring over regeneration when we have wounds or limbs loss.
Scientists found that the absence of the gene P21 in mice gives them the ability to regenerate lost or damaged tissue. This investigation is taking place at the Proceedings of the National Academy of Sciences, and researchers from The Wistar Institute.
Unlike typical mammals, which heal wounds by forming a scar, these mice begin by forming a blastema, a structure associated with rapid cell growth and de-differentiation as seen in amphibians. According to the Wistar researchers, the loss of p21 causes the cells of these mice to behave more like embryonic stem cells than adult mammalian cells, and their findings provide solid evidence to link tissue regeneration to the control of cell division.
We are opening a window into mammalian regeneration 
Read the full article here: Physorg – 1 gene lost = 1 limb regained
