In "The Psychology of Consciousness" by G. William Farthing, we find:
"The adaptive function of ASCs [altered states of consciousness] can be classified in three categories (Ludwig 1966): (1) promoting healing and feelings of well-being; (2) avenues to new knowledge or experience; and (3) social functions."
He then goes on to describe the ways ASCs have been used for these various purposes, but he doesn't have anything to say about innateness. Neither does the word 'evolution' appear in the subject index (nor in the rest of the book, to the best of my recollection). So that's one book you needn't look into... :-)
The Ludwig 1966 is:
Ludwig, A.M (1966). Altered states of consciousness. Archives of General Psychiatry, 15, 225-34. [reprinted in: Tart, C.T. (Ed.) (1972). Altered States of Consciousness. Garden City, NY: Anchor Books (Doubleday). (Originally published by Wiley, 1969.)]
I would be curious to know about any more useful literature on the topic you happen to find.
Greetings,
Eric
efr@dds.nl