About this Book
- Many of the most striking developmental anomalies have evolved into some of the most striking species characteristics (e.g., limbless humans, limbless snakes). (key idea: Body, brain, and behavior are shaped through development, not programmed before development)
- We take for granted how easily we can adjust to an anomalous body when we are allowed to "grow" into it. Key examples: Johnny Eck, the two-legged goat, Faith the two-legged dog (key idea: developmental flexibility)
- Some of the most devastating anomalies -- e.g., two-headedness, cyclopia -- can arise from a mutation or an environmental factor during development. Freaks are not necessarily mutants (key ideas: epigenesis; gene-environment interchangeability)
- Anomalies provide a stark contrast to "intelligent design" and a note of caution to "evolutionary design." They bring us closer to the gears and mechanisms of development, and the options available to evolution.
- Debates over whether Barack Obama is "black" recall similar discussions concerning the nature of sex. Nature often offers ambiguities, and it is the human inability to grasp ambiguity that leads us to force natural products into human categories. But anomalies won't go away so easily, because they are an integral part of nature
In most respects, Abigail and Brittany Hensel are normal American twins. Born and raised in a small town, they enjoy a close relationship, though each has her own tastes and personality. But the Hensels also share a body. Their two heads sit side-by-side on a single torso, with two arms and two legs. They have not only survived, but have developed into athletic, graceful young women. And that, writes Mark S. Blumberg, opens an extraordinary window onto human development and evolution.
In Freaks of Nature, Blumberg turns a scientist's eye on the oddities of nature, showing how a subject once relegated to the sideshow can help explain some of the deepest complexities of biology. Why, for example, does a two-headed human so resemble a two-headed minnow? What we need to understand, Blumberg argues, is that anomalies are the natural products of development, and it is through developmental mechanisms that evolution works. Freaks of Nature induces a kind of intellectual vertigo as it upends our intuitive understanding of biology. What really is an anomaly? Why is a limbless human a "freak" but a limbless reptile-a snake-a successful variation?
What we see as deformities, Blumberg writes, are merely alternative paths for development, which challenge both the creature itself and our ability to fit it into our familiar categories. Rather than mere dead-ends, many anomalies prove surprisingly survivable-as in the case of the goat without forelimbs that learned to walk upright. Blumberg explains how such variations occur, and points to the success of the Hensel sisters and the goat as examples of the extraordinary flexibility inherent in individual development.
In taking seriously a subject that has often been shunned as discomfiting and embarrassing, Mark Blumberg sheds new light on how individuals-and entire species-develop, survive, and evolve.
Readership: American Psychological Association, Society for Neuroscience Association
for Psychological Science, International Society for Developmental Psychobiology,
International Society for Infant Studies, Society for Research in Child Development,
The Teratology Society.
Mark Blumberg, Professor and Starch Faculty Fellow, University of Iowa