This plot seems very similar to the book "A Different Flesh" by Harry Turtledove. The Turtledove has the premise that North America was populated with Homo-Erectus instead of Humans when Columbus arrived and deals with the moral and social issues of human interaction with sub-humans in the last 500 years of history. Homo-Erectus are even named "Sims" by the humans. (The turledove books was written first btw)
I will read anything F.Paul Wilson cares to write. This one a little off-beat but a great and thought provoking story.
I loved this book, medical mystery, horror, murder, intrigue, you name it it was there. Great plot, good characters, like taking a vacation to another place. I love Chimp mystery/horror and this is one of the best I've read.
Fascinating story; I like his Repairman Jack series better, but this is still a worthwhile read by an excellent and creative author.
Book in VG cond..