The Mutations (1974)

Students have been going missing from the local college, and the one person who knows what's happened to them is Dr. Nolter, a rogue biologist. Not satisfied with the pace of natural selection in driving evolution, Nolter wants to push things further by creating his own genetically-engineered creations. Having already created some amazing specimens by mixing the DNA of plants and animals, the doctor has now set his sights higher, and wants to work on modifying humans, as well.