I agree with the other reviewers that if you're looking for a sex film here, you're going to be pretty disappointed. The lead Jenny Neumann has some brief nude scenes, but Barbara Leigh (suprisingly) and British cheesecake actress Suzy Mandel (shockingly) do not. Still Neuman, who was also in "Hell Night" and the Australian film "Stage Fright", is absolutely stunning, and to my knowledge this is the only film where she gets naked at all (Leigh and Mandel, on the other hand. . .). The plot is indeed completely absurd. A woman goes to "equatorial Africa" (it looks a lot more like California) with a group of greedy mercenaries where they encounter a lost tribe of "homo habilitus", basically the missing link between ape and man. After a trigger-happy mercenary shoots the small tribe's only female (which raises a lot of interesting questions of how they've been able to survive so long), the heroine decides to step into the breach, and--bestiality be damned!--she wet nurses one of the infants and makes love to one of the "near-men", eventually become the new "mistress of the apes".
While I can't entirely discount the exploitative value of this movie or the appeal of Neuman, Leigh, and Mandel (even if the latter two are mostly wasted), the best reason to see this really is the director Larry Buchanon. Sure, Buchanon was not the most skilled director in the world, but he was kind of the cinematic equivalent of the punk rock/ garage band that maybe can't play their instruments too well, but are always energetic and creative. And just like I personally prefer a band like that to anything the overproduced LA corporate music industry perennially craps out, I prefer the cash-starved and somewhat incompetent regional directors of the 60's and 70's like Buchanon (who made most of his films in Texas)to any of the modern multi-billion dollar Hollywood stooges like Michael Bay. But while there are still independent bands around today, TRULY independent filmmakers like Buchanon are a rapidly dying, if not already extinct, breed.
Of course, this is not Buchanon's best work--I prefer his classic early 60's film "The Naked Witch" or his bizarre Bergmanesque coming-of-age/sexploitation film "Strawberries Need Rain"--but any Buchanon film is usually worth a look as far I'm concerned, and this one is certainly no exception. See this just for the unique brand of insanity that was Larry Buchanon