National Geographic: A species of lizards has stunned scientists by going through millions of years of evolution in just thirty years.
"Italian wall lizards introduced to a tiny island off the coast of Croatia are evolving in ways that would normally take millions of years to play out, new research shows. In just a few decades the 5-inch-long (13-centimeter-long) lizards have developed a completely new gut structure, larger heads, and a harder bite, researchers say...
...While the experiment was more than 30 years in the making, it was not by design, according to Duncan Irschick, a study author and biology professor at the University of Massachusetts, Amherst. After scientists transplanted the reptiles, the Croatian War of Independence erupted, ending in the mid-1990s. The researchers couldn't get back to island because of the war, Irschick said.
In 2004, however, tourism began to open back up, allowing researchers access to the island laboratory....
...The transplanted lizards adapted to their new environment in ways that expedited their evolution physically, Irschick explained. Pod Mrcaru, for example, had an abundance of plants for the primarily insect-eating lizards to munch on. Physically, however, the lizards were not built to digest a vegetarian diet.
Researchers found that the lizards developed cecal valves—muscles between the large and small intestine—that slowed down food digestion in fermenting chambers, which allowed their bodies to process the vegetation's cellulose into volatile fatty acids.
"They evolved an expanded gut to allow them to process these leaves," Irschick said, adding it was something that had not been documented before. "This was a brand-new structure."
Along with the ability to digest plants came the ability to bite harder, powered by a head that had grown longer and wider....
...The rapid physical evolution also sparked changes in the lizard's social and behavioral structure, he said. For one, the plentiful food sources allowed for easier reproduction and a denser population....
...The lizard also dropped some of its territorial defenses, the authors concluded. Such physical transformation in just 30 lizard generations takes evolution to a whole new level, Irschick said.
It would be akin to humans evolving and growing a new appendix in several hundred years, he said.
Via BoingBoing.
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