This cache was hidden on the 24th of November, which is the anniversary of both the publication of Darwin's "On the Origin of Species" (in 1859) and also the discovery in 1974 of Lucy, a 3.2 million year old Australopithecus skeleton. Lucy is the oldest known example of a bipedal primate and demonstrates a crucial stepping stone in the evolution between apes and homo sapiens.
The cache is a small tube. Not too far away is a large monolith, similar to the one that the apes discovered in Stanley Kubrick's film 2001: A Space Odyssey.
It should be an easy find. Photos of cachers doing ape impressions near GZ would be welcome!