Brain Evolution: Mammals, Primates, Chimpanzees, and Humans

摘要: Though many modern techniques are available for studying brains, they difficult to use in evolutionary contexts that require examination of large numbers specimens and species, all major parts the brain. Thus, studies species whole brains still tend be based upon simpler data such as sizes brain components. Such investigations, carried out over decades, have usually employed univariate bivariate analyses, though a few investigators used early multivariate methods. In mammals, these generally show primacy relationship between brain-part with overall body size. More recent applications confirmed this (Finlay, B. L., Darlington, R. (1995). Science 268: 1578–1584) some also separated highest level phylogenetic groups: strepsirrhines haplorrhines (Barton, A., Harvey, P. H. (2000). Nature 405: 1055–1058). Both findings were, fact, evident earlier (Holloway, L. (1979). Hahn, M. E., Jensen C., Dudek, C. (eds.), Development Evolution Brain Size: Behavioral Implications, Academic Press, New York, pp. 59–88; Sacher, G. A. (1970). Noback, R., Montagna, W. The Primate Brain: Advances Primatology. Vol. 1, Appleton-Century-Crofts, Educational Division, Meredith Corporation, 245–287). However, new employing proportional aimed at conveying input/output relationships components further groupings share convergences lifestyles (de Winter, W., Oxnard, E. (2001). 409: 710–714). brought about by combinations variables seem associated functions implied specific lifestyles. Our most results demonstrate chimpanzees humans especially different from one another, difference is not due size alone. Part merely continuation, towards humans, trend already present across other primates relates mainly neocortical increase. But several independent differences direction primate trend, but mammals examined including nonhuman primates. latter related simply enhancement neocortex, reflect internal relationships. separation so it goes far beyond conventional 98.6% commonality their DNAs. It fits better more molecular, developmental implying considerably greater than recognized.