The literary lineage of Nancy Kress's excellent new novel, Nothing Human, is not difficult to trace. Aware that our species faces acute challenges of survival and transcendence, aliens arrive above Earth in an enigmatic spacecraft, interfere in human destiny by modifying radically the genetic makeup of the next generation, continue their interventions at intervals, and so assist our apotheosis into something else: this is the template of Childhood's End, and quite a few other SF novels, and Nothing Human dutifully follows the script. The notion of an elite of evolved or mutant children is an SF standard, and, while Nothing Human traces moving variations on this theme, it breaks little new ground for it, certainly no more than does Kress's earlier trilogy beginning with Beggars in Spain. The transhumans of Nothing Human are nothing very novel in the details of their enhancement: for example, their sensitivity to airborne chemical messages recalls the spontaneous adaptations in Darwin's Radio and Darwin's Children by Greg Bear. Kress, immensely literate in genre conventions as she is, is not overly concerned with novelty here. In retelling an oft-told story, she is interested instead in eliciting that story's often-obscured guiding truth, a Truth arresting and discomfiting.
Nothing Human is a book of forceful honesty. (It's tempting to speculate that its appearance from a small press stems from a level of honesty not relished by large commercial publishers.) Through the rather melancholy experiences of her large cast of characters, the players in a family saga of unusual consequence, Kress questions whether humankind will still be around in 2100. Her vision of the Final Century can be summarized thus: after years of illusory plenty before and immediately after 2000, global warming and climate change accelerate vigorously, desertifying the world's breadbaskets, more infrequently fecundating deserts; hundreds of millions die, and equal numbers migrate; germ warfare annihilates billions, and spreads lethal vectors across remaining ecosystems; by the 2080s, homo sapiens is a rarity in the scorching deserts, and nothing looks to improve. Anticipating this, the extraterrestrial "pribir" have tinkered with the genes of all embryos passing through a certain late-Twentieth Century antenatal clinic; when these reach puberty, they are the conduit for pribir messages to Earth's governments; some are taken into space for accelerated training in genetics; in due course, a few will have offspring, and these will carry forward the transformation of humanity in an image dictated by the aliens, equal to survival on furnace Earth. So: having doomed our planet to ecological meltdown, we lack the tools and intelligence to stem the cataclysm; our only hope is to become something Other. One dire implication of the title: Nothing Human will come through environmental Holocaust.
This is a looming reality contemporary SF tends to duck. Facing squarely up to it, Kress makes of her pribir a complex metaphor for ruthless Darwinian process: they are simultaneously the forces harrying humankind to destruction and the pressures upon the species to adapt and persevere. Ultimately related to us, and capable of shaping their representatives to appear perfectly human, the pribir adhere to a simple dogma: genetic manipulation is the "right way," technology the wrong path; life must respond to its environment, not alter that environment to its own tastes. Although doctrinaire, error-prone, sometimes amusingly foolish, apt to treat their human pupils with insincere affection or prissy disdain, the pribir amount to a brusque dismissal of genre SF's own inflexible tenet, the ubiquity of technological solutions. Kress's extended family of pribir-adjusted posthumans, its collective standpoint filtered through the consciousnesses of first-generationers Theresa and Lillie and the latter's son Cord, can only go along with the prescriptions of the pribir, all the while tempering the harshness of those prescriptions by means of feisty resistance, militant refusal, sincere counsel, and other contingent strategies. In essence, Lillie and her tribe are moderating their transition into full posthumanity by being as human as possible: their glory and their sacrifice. Something of them will live on after all, the legacy of their stubbornness.
So there is hope of a kind, and Nothing Human concludes on an extraordinary rhapsodic note. This is, in spite and because of its fearsome prophetic burden, an intensely human book. Kress draws her fraught character portraits with sympathetic economy: Lillie's na´ve mother Barbara, her capable Uncle, Keith, Lillie, philosophically adventurous before eventual emotional awakening, Theresa, the cautious matriarch, and so on through a surprisingly extensive dramatis personae that expands across the decades even as the planetary population dwindles away. There are powerful scenes: the bizarre academic environment aboard the pribir ship collapsing into unthinking bacchanalia; ensuing multiple births down in primitive New Mexico; death and rebirth in a sandstorm; laughable scoldings by the pribir; a marvelous yet doubtful glimpse of a new Eden. This is the essence of elegy, perhaps: a reminder of what we are losing, a reassurance as to what remains. However sad and alarming, Nothing Human is a tribute to Everything Human.
— Nick Gevers, Locus, September 2003