Stir over chicken from T rex theory

Almost 70 million years after the Tyrannosaurus rex strode the earth, a controversy over whether the modern chicken is the fearsome dinosaur's descendant is rampaging through the scientific world.
In a letter to the journal Science published on Thursday, University of California, San Diego, scientists attacked methods used by a Harvard University-led team that proposed the T rex-chicken link in April 2007.The Harvard team responded in a letter to the same journal, saying their analysis of the dinosaur's protein is sound.
The original Harvard study found suspected T rex protein fragments appeared to match a common protein, called collagen, in chickens, supporting a long-suspected link between birds and dinosaurs. Critics of the study say the findings may be random, and there isn't enough information about other species' proteins to say whether the match with chickens is definitive.
"The statistical meaning is hard to judge without a lot of additional data," said Michael Hofreiter, an evolutionary scientist at the Max Planck Institute in Leipzig, Germany, in a telephone interview on Friday.
"Personally, I doubt that the link is real." The Harvard study's findings have preoccupied scientists who study ancient tissue and molecules believed to have been preserved for thousands to millions of years, said Hofreiter, who isn't part of either team. Without more data on other species'' proteins it's not possible to say whether the match with chickens is better than it might be with reptiles, he said.
Harvard approached the problem like a boy who finds that his monkey's random typing matches some words in a dictionary, researchers led by Pavel Pevzner, director of the center for algorithmic and systems biology at the University of California, San Diego, said in a stinging letter in the Science journal.
"The boy is so surprised that he writes a paper called ���My monkey can spell!' the UCSD researchers wrote in their letter. "Some scientists are not convinced."
The Harvard team earlier came under fire in September when Enrico Cappellini, an archaeologist who studies ancient proteins at the University of York in the U.K., suggested they had overlooked other possible interpretations of their data. Cappellini's letter also was published in Science, just weeks after the Harvard researchers had volunteered a correction of some of their work.
"I'm not surprised that other people have found issues in these results," Cappellini said Thursday in a telephone interview.
John Asara, a Harvard pathologist at Beth Israel Deaconess Medical Center in Boston who led the 2007 dinosaur study, said that while his group's methods are unconventional, they are scientifically valid. Collagen is one of the few proteins that has been well studied in many species, and is highly similar from one to the next, he said.
Subsequent studies have also shown strong matches between T rex protein and ostrich collagen, he said.