Robert Silverberg 
Son of Man 

IN THE BEGINNING . . .There was no Brooklyn, no St. Louis, no Shakespeare, no moon, no hunger, no death . . .IN THE BEGINNING . . .There were no real men, no real women, nothing but the dispassionately passionate ambisexuals of the lowest and highest order . . .IN THE BEGINNING . . .The heavens, the seas and the Earth belonged to a more intelligent species than a man called Clay could ever have dreamed possible in his own time . . . but his own time as a man had passed, and now his time as the son of man had come!