In their first detailed and comprehensive look at the DNA of chickens, scientists have found that 60 percent of the bird’s genes have close cousins in humans. They say such analysis should prove valuable in learning more about the human genome. But as to the great mystery of why the chicken crossed the road, no answers yet. “That question is still out there,” said Richard K. Wilson of the Washington University School of Medicine in St. Louis. He’s senior author of the chicken DNA analysis, which is presented by an international team of scientists in Thursday’s issue of the journal Nature.