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Geckos in Namibia evolved to lose sticky feet in desert

Move it or lose it. In the case of geckos studied in Namibia, it's an adage that seems to have stuck.

High-speed geckos abandoned 'adhesive system' to run more easily in arid environment

A Rhoptropus afer gecko photographed by the research team in Namibia identified this species as one with reduced adhesive capabilities that runs at high speeds. (Timothy Higham/University of Calgary)

Move it or lose it. In the case of geckos studied in Namibia, it's an adage that seems to have stuck.

In a study of the evolution of gecko locomotion, University of Calgary biology professor Anthony Russell and his colleagues observed that as geckos moved from more forested areas to the hyper-arid environs of Namibia, they apparently no longer had much use for the adhesive undersides that would allow their feet to cling to surfaces.

"Geckos have moved out onto these plains where there are no real surfaces to stick to, and have found new ways to get about," Russell told CBC Radio's Bob McDonald on Quirks & Quarks.

The geckos' movements were observed with high-speed cameras. Some species simplified their adhesive systems while others abandoned those abilities completely, Russell said.

Instead, it appeared that the adhesive system on desert geckos "shifted" to the far ends of their toes, allowing the desert geckos to run long distances over flat terrain.

Geckos living in the desert have lost their sticky toe pads. 8:20

The researchers found that as the geckos ran at high speeds, they curled the ends of their toes upward.

'Sand shoes'

"They only deploy the adhesive system when they're on an incline and need to stick to something," Russell said.

Russell also explained that webbed feet resembling "sand shoes, or snow shoes" may have helped geckos run without sinking in looser sand, and that gecko toes may have also evolved to assist with burrowing in quartz-type soil.

Russell and other scientists published their findings last week in the journal Proceedings of the National Academy of Sciences.

To listen to the full interview, tune in to CBC Radio's Quirks & Quarks with Bob McDonald on CBC Radio One, Saturdays at noon, Mondays at 11 p.m. and Wednesdays at 3 p.m. ET.