"The Xolotl salamander found in Mexico is an example. Scientists, moved by the plight of this beautiful creature, gave him an injection of hormones, whereupon he shed his gills and left the water after ages of neoteny. It is perhaps too much to hope ihat one simple injection could jar the human species out of its neoteny. But by whatever means the change takes place, it will be irreversible. The Xolotl, once he sheds his gills, can never reclaim them. Evolution would seem to be a one-way street"
William S. Burroughs - Women: A Bilogical Mistake? http://cdn.realitystudio.org/images/bibliographic_bunker/mens_mags/pdf/1978.03.playgirl.pdf