In the paper by Kaufman et al., a notably high encephalization
(ratio between actual brain mass and predicted brain mass for an animal of a given size) is reported in sengis and this has been interpreted to mean that brain-body allometry in the sengi matches that of larger-brained non insectivorous groups rather than smaller-brained insectivores.
According to recent genome studies, a significant correlation between MACROD2 CNVs and schizophrenia, brain infarction and encephalization
has been reported (24).
All of the elements that have underpinned the development of human cognitive abilities -- encephalization
(the evolutionary increase in the size of the brain), tool use, teaching, and language -- have one key characteristic in common: The conditions that favored their evolution were created by cultural activities, through selective feedback.
Strategically, American intellectuals have pursued their advancing roles in globalization, encephalization
, multiculturalization, and multiethicalization knowledge as successful leaders in the global community of scholars.
The most functionally significant comparison between brain sizes is the encephalization
quotient (EQ), the expected brain size given the size of the body.
But, by any (or several) of these measures, the cognitive capabilities of whales, dolphins and elephants are the most similar to that of humans (outside of primates), with dolphins' "encephalization
quotient" of 4.2 being the closest to that of humans (7.0) than any other animal, including primates.
(While acknowledging several other potentially useful neural metrics--cortical neuron numbers, encephalization
quotients, and brain/body ratios --I specifically examine brains here for their [[PHI].sub.m] values in order to be scrupulously consistent with my proposed complexity metric of energy rate density for all complex systems.) However, brain metabolic values gathered from the literature often suffer, as noted above for bodies, from a lack of standard laboratory methods and operational units; many reported brain masses must be corrected for wet (live) values (by multiplying measured in vitro dry masses by a factor of 5 since in vivo life-forms, minus their bones and including brains, are ~80% [H.sub.2]O).
Other derived diagnostic traits of euprimates, uncommon in other mammals, are the following (e.g., Martin, 1990; Rasmussen, 2002): postorbital bar; orbital convergence, yielding stereoscopic binocular vision; grasping hands and feet, usually with opposable hallux and pollex; flat nails instead of claws on most digits; brains larger than expected on the basis of body size (high encephalization
); and a slow life-history profile.
The process by which some species evolved larger brains -- called encephalization
-- is not well understood by scientists.
In the course of evolution, as a result of encephalization
, the motor functions of particular elements of the CNS become more and more "fuzzy" distributed among spinal cord, cerebellum, basal ganglia and cortex.