Thursday, August 17, 2006

"The Gene that Makes Us Human?"

Technology Review, By Emily Singer
"In the new paper, researchers at the University of California, Santa Cruz compared the human genome to the genomes of chimps, dogs, rats, mice, and chickens, searching for genetic sequences that were highly conserved during evolution and therefore functionally important. They then looked for sequences within those conserved regions that had changed rapidly in humans, indicating that those changes were important for human's unique evolution.
The researchers identified several rapidly evolving chunks of DNA, but the fastest piece by far was a small chain of DNA that's part of a gene expressed in the hippocampus, which is involved in learning and memory. According to the findings, the sequence was very similar in chickens and chimps, with only two changes to the genetic code; but it had changed remarkably in human DNA, showing 18 genetic differences from the version in chimps. "