 In fact this structure in invertebrates and the pallium in vertebrates may have a common evolutionary origin from a common ancestor.Given the apparent function of the sensory-associative structure, it has been suggested that the total number of neurons in the pallium or its equivalents may be the best predictor of intelligence when comparing species, being more representative than total brain mass or volume, brain-to-body mass ratio, or encephalization quotient (EQ).It may thus be reasonably assumed that the total number of neurons in an animal's corresponding sensory-associative structure strongly relates to its degree of awareness, breadth and variety of subjective experiences, and intelligence.