Evolving Brains.

• Author: KREYCHE, GERALD F.
• Position: Review

Evolving Brains by John Morgan Allman / Scientific American Library, 1999, pp. 224, $34.95

For centuries, the human brain virtually was ignored in scientific investigations, as other organs of the body--such as the heart, lungs, liver, etc.--took preference. When 16th-century philosopher and mathematician Rene Descartes had the temerity to suggest that the soul was located in the brain's pineal gland, his view was ridiculed as positing that there was a "ghost in the machine."

Brain research, outside of such fads as phrenology, didn't become serious until the localization center for speech was discovered in 1861. (A man who could pronounce only one word, "tan," died and an autopsy revealed a lesion in that part of the brain.) Recent studies show that "the finer the degree of control and use of a muscle, the larger its representation in the cortex." Examples of this growth are found among people who read Braille and those who play stringed instruments.

In today's technological age, new tools penetrate neurological mysteries. Among them are MRI (magnetic resonance imaging), oscilloscopes, scanning electron microscopes, and microelectronic recordings. Additionally, neurological studies are strongly interdisciplinary.

While Evolving Brains is sophisticated with its charts, graphs, and mathematical formulae, most educated readers will find it invaluable in giving a good general picture of ongoing evolution. Copious examples and pictures keep one going to the end.

Creationists may be jolted by its factual documentation of evolution and natural selection and how this applies to brains. Allman shows how evolution explains both the diversity and unity of nature. A...