Frogs: Female choice for complex calls led to evolution of unusual male vocal cord
Wednesday, May 03 2006 @ 08:51 PM UTC
Contributed by: Don Winner
"The experiment shows that the fibrous masses produce the complexity in the calls of male túngara frogs," adds Gridi-Papp, who was a post-doctoral researcher at Universidade Estadual Paulista in Brazil during this study.
Taken together with the fact that female preference for complex male calls most likely evolved before males could actually produce them, Gridi-Papp says this shows that the fibrous masses on the male vocal cords evolved in response to female preference.
"Besides shaping the behavior of males, female preferences also indirectly shape the anatomy of the calling apparatus of males by favoring enlarged fibrous masses that allow for production of complex calls," says Gridi-Papp.
"The simple connection between the fibrous mass and call complexity gives us a unique opportunity to dissect the evolution of acoustic complexity," Gridi-Papp says.
Comparative studies looking at the fibrous masses of other species in the same genus may reveal why complex calling evolved in the túngara frog lineage and not in others.
Such studies will help explain the origins of complex traits, one of the major evolutionary questions for biologists since Charles Darwin.
Source: Smithsonian Tropical Research Institute