Heavy incorporation of author's own sensibilities into an already sensitive topic makes this a questionably preachy journey. As far as believability is concerned it suffers from fluctuations; at some points, the raw realism resonates stupendously only to be dulled by the timeworn twists any experienced reader will be able to predict. Ironically, a major positive element is the lack of any sort of unorthodox turnaround, sort of teases one's expectations but always remains down to earth in that respect - as opposed to its philosophical innuendos.
Infamously drawn "clones" offer distinction on a personality basis at least, but more or less are victims of your everyday survivalist devices. They do succeed as proxies of the author's own standpoints, even make you ponder over some existentialistic dilemmas and sanctity of life itself. However, their naivety is pushed to the extreme for the sake of convenience and therefore drowns in absurdity. At a certain point, it feels as if they'll free themselves from the author's moralistic clutches, develop autonomy to break the fourth wall, and ask the reader: "Do you really believe this?"