using stem cell technology–cloning. The most famous one being the wholly mammoth of course:
The whole article here
I just stumbled upon an article where scientists from UCSF claim to have discovered endogenous pluripotent somatic cells comparable to hESC, said to be stable and mortal. They fit stemness as defined by most including Shinya Yamanaka’s, but however have different expressions, surface markers and other characteristics than those found with hESC. Isn’t being mortal for a cell forbidding it from fitting stemness?