Because paddlefish doubled their genome?
From “Paddlefish’s Doubled Genome May Question Theories On Limb Evolution” (Science Daily, August 6, 2012), we learn,
The American paddlefish — known for its bizarre, protruding snout and eggs harvested for caviar — duplicated its entire genome about 42 million years ago, according to a new study published in the journal Genome Biology and Evolution. This finding may add a new twist to the way scientists study how fins evolved into limbs since the paddlefish is often used as a proxy for a more representative ancestor shared by humans and fishes.
“We found that paddlefish have had their own genome duplication,” said Karen Crow, assistant professor of biology at San Francisco State University. “This creates extra genetic material that adds complexity to comparative studies. It may change the way we interpret studies on limb development.”
“Our findings suggest that the results of previous studies using paddlefish as a comparative species may need to be re-interpreted,” Crow said.
How be this: Be polite to the lecture room bore because being a lecture room bore is a big enough punishment that he should not have to put up with rude students. And huffing certainties may be good for his lungs or something. But whatever happened back there, no one really knows.