The Evolutionary Record
by Thea Iberall

Context for "The Evolutionary Record"

I studied the human hand for twelve years. I was fascinated by it because, in conjunction with the brain, it has built every human-made thing around us.

What is a human hand? It took about fifty-five million years for it to evolve from the mammalian paw into the prehensile masterpiece it is today ('prehensile' means the ability to grasp). As our ancestral species were first forced into the arboreal life of the rainforest and then out onto the savannas of Africa¹ (or between arboreal and terrestrial food sources as suggested by a new theory²), the appendage began to change: fingers became differentiated with architectural support from long tendons and uniquely shaped wrist bones. Fingertips flattened and filled with sensory receptors, as small muscles became located within the hand for movements of adduction and abduction (spreading fingers out and in).^3,4 Importantly, the thumb began to shift to a position in opposition with the other fingers, slowly forming a triumvirate of thumb, index, and middle finger. What emerged was the precision grip,⁵ an exquisitely crafted tool for fine manipulation. Try picking up coins, turning a small screwdriver, or opening a pill bottle -- these actions all use the precision grip.

The synchronicity of what happened about 5,000 years ago still amazes me. Human society had developed the need for record keeping that would put this precision capability to use in the form of holding an implement for writing. The skill and the need coalesced into a foundation for all of written history.

Interestingly, linked with the appearance of writing has been the establishment of hierarchical societies,⁶ a phenomenon noted by Dr. Leonard Shlain as possibly rooted deep in the human nervous system. He argues that literacy promotes linear and abstract thinking at the expense of more holistic and integrative views of the world. As a result, the male brain, already geared towards linear behaviors for hunting, took to (although, didn't necessarily invent) writing and was made more powerful by it. This, Shlain’s argument goes, formed the birth of the patriarchy.
Hands are tools that make tools. Today, with computers, will we lose the ability to write by handwriting? And will multimedia, image oriented languages emerge and perhaps someday create more egalitarian societies that accept all the varieties of humans?

1. Washburn. Sherwood L., Tools and Human Evolution, Scientific American, Sept, 1960 (Reprinted in Human Ancestors, Readings from Scientific American, San Francisco: W. H. Freeman and Company, 1979).
2. Kingdon, Jonathan. Lowly Origin, NJ: Princeton University Press, 2003.
3. Napier, John R., The Evolution of the Hand, Scientific American, 207(6): 56-62, 1962 (Reprinted in Human Ancestors, Readings from Scientific American, San Francisco: W. H. Freeman and Company, 1979).
4. Wilson, Frank R., The Hand, NY: Pantheon Books, 1998.
5. MacKenzie, Christine L. and Iberall, Thea, The Grasping Hand, NY: Elsevier-North Holland, 1994.
6. Shlain, Leonard, The Alphabet versus the Goddess, NY: Viking, 1998.

The Evolutionary Record

A hand can shape itself into a form
evolved for picking insects and apples

yet by the shadowed light of a fire
a woman’s hand picked up a half bent reed

drove it into a mass of wet clay
marking the simple first

exchange of five of her husband’s brown
goats for round tokens

leaving the other side of the slab
free to write the blood of her gender

Published in The Southern California Anthology, Vol. XVIII, 2003.