Thursday, May 28, 2009

Hardware or Software?

Never mind nature versus nurture, the real question we should be asking about human origins is "hardware or software?" argues Duke biologist Greg Wray.

Wray gave a pizza lunch seminar at Sigma Xi's headquarters in the research triangle on Wednesday to share his view that biology's fixation on the "hardware," the coding sequences of DNA that carry blueprints for specific proteins, has obscured the more interesting story, the regulatory sequences, or "software" that tell those coding sequences when, where and how to take action.

"The diversity of life is magical. It's wonderful. It's why I'm a biologist," Wray said. "But we don't really know how it came about."

Recent science on these regulatory regions of the genome is revealing two things: 1. a bewildering complexity of genetic regulators and on-off switches that we never new existed, and 2. quite a bit of evidence that selection acts more strongly on regulatory sequences than on coding sequences.

"The regulatory regions are the fine-tuning dials of evolution," Wray said.

The most obvious example of this is staring us in the face, Wray said. The DNA of humans and chimpanzees is only about 1 - 2 percent different. Granted, 2 percent of 3 billion letters of code can be a lot of information, but aren't the differences between our species more profound than 2 percent?

Wray's cart-tipping act is making some fun waves in the science community. (see Science Magazine, Aug. 8, 2008). And, fresh off the triumphant publication of the complete sea urchin genome (no, really!), watch for Wray soon in landmark papers about malaria resistance and the size of the human brain.