Travis Hagey, Michigan State University evolutionary biologist, shows how different groups of lizards — geckos and anoles — took two completely different evolutionary paths to developing the beneficial trait of sticky toe pads.
In a paper published in the journal Evolution, Hagey showed that anoles seemed to commit to a single type of toe pad, one that generates lots of friction. As a group, they were able to develop sticky toe pads early. Geckos, meanwhile, opted for an evolutionary “drunken stumble,” and seemingly didn’t commit to a single approach, instead evolving toe pads that generate plenty of friction in some species and others that excel at sticking directly to a surface.
“We’re trying to explain how evolution works and how predictable it is,” said Hagey, who’s part of MSU’s BEACON Center for Evolution in Action. “Good science answers one question while producing more questions. Anoles and geckos are two different large groups of lizards. They live on different continents, and evolutionarily, they’re separated by 250 million years of time. So even though they have some of the same traits, you can’t assume that they were developed the same way.”
Evolution is a tinkerer, he added. Hagey likens it to a person who lives on a dirt road and decides to build a bicycle. Paper. (paywall) – Travis J. Hagey, Josef C. Uyeda, Kristen E. Crandell, Jorn A. Cheney, Kellar Autumn, Luke J. Harmon. Tempo and mode of performance evolution across multiple independent origins of adhesive toe pads in lizards. Evolution, 2017; 71 (10): 2344 DOI: 10.1111/evo.13318
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