The researcher said these multiple adaptive bursts caused evolutionary redesign of many proteins in the snake.
"We first saw these unusual molecular patterns in the snake mitochondrial DNA, and now it seems they extend throughout the nuclear genome," Pollock said.
The team also found that after Burmese pythons ate, they experienced massive changes in gene expression linked to 35 to 100 percent size increases in their heart, small intestine, liver and kidneys in just 24-48 hours.
Meanwhile, the snake's metabolism, among the lowest of any vertebrate, ramped up significantly. Pollock compared the increase to a horse going from standing still to running a quarter mile race; but the snake isn't moving, just digesting.
"Genes that were fully off are now full on," he said. "Snakes eat animals as big as themselves. Once they catch something that size, they need to digest it quickly before it rots in their stomach, and they have to turn a lot of genes on to do it."
The study said phenotypic novelty in snakes appears to be driven by the system-wide coordination of protein adaptation, gene expression and changes in the genome structure.
Pollock noted that the findings not only offer insights into how evolution works at the molecular level but they also have implications for humans.
"What we are seeing now can apply to people," he said. "We can link mutations to physiological effects and perhaps find a way to stop those mutations before they cause disease. There are any number of possibilities and we are only starting to unravel them."
|Contact: david kelly|
University of Colorado Denver