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No. 77: Sep-Oct 1991

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Cooler heads, bigger brains?

When anthropologist D. Falk discovered that an automobile's engine was limited in power by its radiator's capacity to cool it, he applied this thinking to the human brain.

The human brain, like the automobile engine, must be kept cool if it is to function well. It follows that if the brain of an animal is not functioning well, the body that brain controls will not perform well either. Overheated brains, then, are sure roads to extinction in the highly competitive natural world. A couple million years ago, two groups of human precursors were competing for dominance in Africa. The group that won and subsequently evolved into Homo sapiens had, according to Falk, a better brain-cooling system. The evolutionary development that probably led to this advantage was a more extensive network of emissary veins, which permitted better dissipation of heat. This, in turn, allowed the evolution of larger brains and dominance by Homo sapiens. Other anthropologists, how ever doubt that such a minor change in the circulatory system could account for the emergence of modern man. (Shipman, Pat; "Hotheads," Discover, 12:18, April 1991.)

Comment. What an intriguing concept! Perhaps human male baldness also confers more cooling efficiency and is setting the stage for a new expansion of the human brain -- at least the male brain, sorry girls! More seriously, did the better blood cooling system develop in response to an enlarging brain, or vice versa? Even more seriously, it is simplistic to say that an organism just went ahead and evolved this way or that way. A bigger brain requires not only more cooling but a bigger skull, more neurons, more connections between them, and additional infrastructure. Saying simply that "a larger brain evolved" obscures the fact that many different, inheritable changes had to take place in synchronism.

From Science Frontiers #77, SEP-OCT 1991. 1991-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987