Untamed Heart agent, MGM had greenlighted the project. Originally, the film was titled "The Baboon Heart" in honor of an infant named Baby Fae (born 14 October 1984) who received a cross-species heart transplant from a baboon to fix a congenital heart defect. Initially, Bill had not considered Christian Slater for the role of Adam, “but then it was just the obvious choice." For the role of Caroline, Bill remembered auditioning Marisa Tomei for his earlier film, "Five Corners". While she had been too young for that role, after her success with "My Cousin Vinny" he felt she was right for the
Baboon as a full species, but regard all the others as subspecies of "P. cynocephalus" and refer to them collectively as "savanna baboons". This may not be helpful: it is based on the argument that the hamadryas baboon is behaviorally and physically distinct from other baboon species, and that this reflects a separate evolutionary history. However, recent morphological and genetic studies of "Papio" show the hamadryas baboon to be more closely related to the northern baboon species (the Guinea and olive baboons) than to the southern species (the yellow and chacma baboons). In 2015 researchers found the oldest baboon fossil dating