'Freaks' help scientist unravel nature a...( In 1940 a Dutch goat born without fr...)

In 1940, a Dutch goat born without front legs learned to walk upright.

So did Faith, a two-legged dog in Oklahoma.

Johnny Eck, a "half-man" born without legs, grew naturally into a graceful hand-walker.

And in Minnesota, conjoined twins Abigail and Brittany Hensel live successfully with separate heads connected to a single body. Each girl controls her own arm, but they manage to drive, swim, shuffle cards and play piano.

In his latest book, "Freaks of Nature," University of Iowa psychologist Mark Blumberg examines nature's oddities as a window for exploring the development and evolution of body, brain and behavior. He focuses on physical abnormalities -- how they happen and how creatures adjust to them -- to illustrate his belief that nature and nurture are inseparable and equally important to development.

"To me, the nature-nurture debate is a dead end," said Blumberg, who teaches behavioral and cognitive neuroscience in the UI College of Liberal Arts and Sciences. "Asking whether something is more nature or more nurture is like asking whether a hurricane is more wind or rain. It's both -- always both."

Blumberg's book is written for a general audience, but his ideas are creating a buzz in the scientific community. In a book review published recently in the journal Nature, Jerry Coyne at the University of Chicago argued that Blumberg doesn't give enough weight to genes. In Blumberg's response, published in the same journal this month, he explained his belief that genes do play a key role in development, but that they're only part of a complex developmental process comprising both genetic and non-genetic factors.

Genetics get a lot of attention in part because it's easy to explain differences by saying "it's in the genes," Blumberg said. But there was no specific gene to tell the Dutch goat to walk upright, or to teach the Hensel twins to coordinate their motions when they swim or pl
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