If you hopped along with Watership Down or whooped it up with Hanta Yo, you might just go for this startling novelty item which, like a statuette of Venus de Milo with a clock in her stomach, unites the informative with a livelier art: anthropological speculations about the Ice Age illustrated by the odyssey of a remarkably sophisticated Clan of Neanderthals and their Cro-Magnon foundling, Ayla. Adopted as a child by the beetle-browed Clan of the Cave Bear after her people perish in an earthquake, Ayla looks different and is different: the frontal lobes of her brain are more developed than those of the back-brained Clan. (The Clansfolk do, however, have extraordinary memories which reach back to their own evolution.) Still, odd little Ayla is mothered by medicine woman Iza; she reveres her father-figure and mentor, Magician (Mog-ur) Creb, whose brain is the best of the Clan, mystical-memory-wise; and it is Creb who shockingly proclaims that Ayla (who has been clawed by a lion) belongs to the most powerful male totem, the Cave Lion, and is not meant to be docile and subservient. Indeed, with her "forward-thinking frontal lobes," Ayla teaches herself to hunt (forbidden to women), revealing her secret when she saves a child from a beast. And at last she is accepted as the Woman Who Hunts after surviving a "Death-Curse" (a month alone). But when abusive, angry Broud impregnates Ayla, she bears a mixed-breed child and later must leave child and Clan when Broud becomes leader. . . though the Clan is doomed and the emergence of a new human being is on its way. True, Auel's Neanderthals often have some awfully peculiar notions cooking on those back brains of theirs. And anachronisms run wild through the wilderness ("You call yourself a hunter," says the Clan leader, "You expect to control a clan when you can't even control yourself?"). But it's all written with nerveless esprite admirable scenery, swell sex, convincing artifacts and survival modese and, when clubbed on by heavy publisher advertising, this first novel (first of six in a projected early-man series) may well prove curiously primitive enough to catch on in a big way.