杏吧原创

Lizards on the Caribbean island of Dominica appear to have suddenly developed a super strong grip. Measurements before and after a hurricane hit the island reveal the lizards鈥� grip has become ten times stronger 鈥� although it is not clear why.

In September 2017, Category 5 strength hurricane Maria devastated Dominica and may have drastically altered some of the nation鈥檚 wildlife.

Claire Dufour at Harvard University and her colleagues were in Dominica in 2016, studying the coexistence of two types of lizard: invasive crested anoles (Anolis cristatellus) and native anoles (Anolis听辞肠耻濒补迟耻蝉). The team captured the lizards, recording the two species鈥� body size and toe features, as well as their clinging ability by measuring the force required to drag their feet along a surface.

After the hurricane, Dufour and her colleagues wanted to see if it had affected any of these characteristics, so in 2018, they returned to Dominica to re-sample the anoles.

While body size and toe pad shape didn鈥檛 change, both anole species had dramatically stronger grips following hurricane Maria, about ten times stronger than their 2016 counterparts.

One possibility is that anoles with stickier feet fared better in the hurricane鈥檚 violent winds, meaning the remaining population grew from a group of the strongest clingers.

鈥淭his study shows that hurricanes may be a previously overlooked driver of performance in Anolis lizards,鈥� says Dufour. 鈥淭his is pretty unique.鈥�

Getting a grip

Last year, Dufour鈥檚 colleagues that showed a different Caribbean hurricane spurring changes in toe pad shape in anoles, but this is the first study showing the lizards increasing their grip after a storm.

The massive change in grip strength is surprising, says Philip Bergmann at Clark University. 鈥淚f this is an evolutionary change in clinging performance, then this must be one of the fastest rates of evolutionary change over a short period of time ever reported.鈥�

So is it actually evolution? Maybe, but Dufour says more information on the variation and heritability of the clinging trait is required. The grip boost may not be inherited in future generations and could eventually disappear.

To better understand these overnight super-clingers, Dufour wants to see if subtle changes in setae 鈥� microscopic toe pad hairs 鈥� helps explain the jump in grip strength. She also wants to survey the anoles鈥� grips again, to see if the reptiles鈥� newfound powers stick around.