Coffee!!: Desperately seeking unshot wildlife biologist
|March 5, 2011||Posted by O'Leary under Evolution|
In “Frogs Evolve Teeth – Again: Mysterious re-evolution challenges evolutionary theory, scientists say”, Christine Dell’Amore (National Geographic News, February 10, 2011) tells us,
Lower-jaw teeth in frogs re-evolved after an absence of 200 million years, a new study says. The discovery challenges a “cornerstone” of evolutionary thinking, according to experts.Of the more than 6,000 species of frogs, only one, a South American marsupial tree frog called Gastrotheca guentheri, has teeth on both its upper and lower jaws. Most frogs have only tiny upper-jaw teeth.
Apparently, G. guentheri has acted in violation of Dollo’s law, according to which traits lost through evolution cannot be regained.
“It’s a very clear case of reacquisition of a lost complex morphological structure, which, according to current thinking, should not be possible.”
Well one thing for sure, that frog’s gotta go. Worse:
“The fact that toothlike structures appear more often than real teeth means that tooth evolution doesn’t automatically occur when the need arises, Yale’s Wagner noted.With that in mind, natural selection – the process by which favorable traits become more common over time within a species – is “not enough to explain” why the marsupial tree frog regained its lower teeth.
“I can confidently say that we don’t know,” Wagner said. “It’s an extremely interesting question.”
A friend wonders, “Did this guy get shot for saying this?”
I dunno. Anyone seen him around lately?
Texas Darwin lobby, please note. Another subject to cross off the list of what students can hear about.