Isaac Asimov
Child of Time (The Ugly Little Boy)
1991
from the dustjacket by Wayne McLoughlin:

First published in Galaxy magazine in 1958, Isaac Asimov's short story "The Ugly Little Boy" is a science fiction classic. Now, in the second collaboration between the late, great Isaac Asimov and award-winning author Robert Silverberg, we have The Ugly Little Boy, the novel, a remarkably moving and chilling tale of what happens when past and present collide.

When Stasis Technologies, Ltd., plucks a Neanderthal child off the prehistoric tundra and transports it into the twenty-first century, the scientific conglomerate gives no thought to the creature's human feelings. The nurse assigned to the case must somehow bridge the 40,000-year gap to forge an emotional bond that transcends time. And, when Miss Fellowes learns of the intended disposition of the "Timmie experiment," it is up to her to travel back through time with the "ape-boy" as he rejoins his tribe on the cutting edge of civilization.

Exquisitely crafted, with compelling scenes of life from prehistory and the not-so-distant future, The Ugly Little Boy is a grand sweep through time that gives us humanity both in its infancy and at its most "civilized."