In anthropology, the study of primate evolution was dominated by
            
 three main theories.  Primate evolution studies were triggered by the
            
 question, "how early shrew-like mammals develop into the  first primates'"
            
  Three dominant ideas emerged from this scientific question.  The  first
            
 primate evolution theory, the ARBOREAL THEORY, is proposed by W. Jones in
            
 1916.  In this theory, Jones posited that enhanced primate characteristics
            
 such as grasping hands and feet, binocular vision, and cognitive processing
            
 are results of primates' adaptation to arboreal life.  However, the
            
 weakness of this theory is that it does not explain how some arboreal
            
 mammals do not possess the characteristics most arboreal mammals to have at
            
 present and yet, managed to survive throughout the ages.  The MIXED-DIET
            
 On the other hand, THEORY argues that increased exploitation of
            
 angiosperms yielded to the development of primate characteristics.
            
 However, the formulation of this theory is based on the VISUAL
            
 PREDATION THEORY is considered perhaps the approach that best explains the
            
 nature of primate evolution.  Proposed by Matt Cartmill in 1974, the theory
            
 argues that arboreal predatory behavior determined the development
            
 of primate characteristics of grasping hands and feet and increased vision
            
 and cognitive processing (also related to an increase in brain size).  The
            
 visual predation theory is an example of a scientific approach that looks at
            
 behavior as a precursor to actionâ€". That is, for development to
            
 occur, a stimulant is needed.  In Cartmill's theory, the inspiration or
            
 catalyst that helped occur primate evolution and development is its nature
            
 to survive.  To provide means to survive, mammals that thrived and
            
 increased in a population 65 million years ago had survived and developed by
            
 evolving their physical and cognitive characteristics, i.e., bodily
            
 features are altered to adapt to their needs and cognit...