Geckos have independently evolved their trademark sticky feet as many as 11 times, and lost them nine times, according to research published June 27 in the open access journal PLoS ONE.
There are about 1,450 known species of geckos, and about 60 percent of them have adhesive toepads. The researchers behind the current study, led by Aaron Bauer of Villanova University in Pennsylvania, analyzed the DNA of many gecko species to determine their family relationships and construct the most complete gecko family tree yet. Then, they added the information about whether or not each species had adhesive toepads to determine how the different versions of sticky feet arose. The most likely model, they concluded, is that adhesive toepads arose 11 times, and were lost nine times, over the course of gecko evolution. Overall, the toepads are externally very similar, despite independent evolution, but the authors write that each independent lineage does have visibly unique anatomy.
"Scientists have long thought that adhesive toepads originated just once in geckos, twice at the most," says University of Minnesota postdoctoral researcher Tony Gamble, a coauthor of the study. "To discover that geckos evolved sticky toepads again and again is amazing."
The gecko's amazing clinging ability has inspired engineers to develop various biomimetic technologies, and the new work may help further this work. "Gaining a better understanding of the complex evolutionary history of gecko toepads allows bio-inspired engineers to learn from these natural designs and develop new applications," says co-author Anthony Russell, of the University of Calgary.
Citation: Gamble T, Greenbaum E, Jackman TR, Russell AP, Bauer AM (2012) Repeated Origin and Loss of Adhesive Toepads in Geckos. PLoS ONE 7(6): e39429.doi:10.1371/journal.pone.0039429
This research was supported by grants from the National Science Foundation and by Discovery Grant from the Natural Sciences and Engineering Research Council of Canada.
Contact: Lindsay Morton
lmorton@plos.org
41-593-520-94197
Public Library of Science
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