Jason Kolbe, the professor of biological sciences from the University of Rhode Island, decided to measure the length of the legs and size of the toe pads of various lizards to understand more about the factors that influence the ability of lizards to grasp on to vegetation during strong storms. Kolbe also employed a powerful leaf blower to test his own hypotheses in laboratory conditions.
A postdoctoral colleague of Kolbe’s from Harvard University measured the limb lengths and toe pads of lizards that lived on the Turks and Caicos Islands some four days before Hurricane Irma hit the islands last September. Two weeks later Hurricane Maria also struck the islands.
The storms proved to be a bizarre opportunity for scientists to understand how hurricanes influenced the evolution of the lizards on the Islands. Kolbe’s Harvard colleague paid another visit to the Islands just weeks after the hurricanes. The findings of both of his and Kolbe’s work were published recently in the journal Nature.
“Our previous studies suggested that lizards with longer limbs and larger toe pads can cling better, so we expected that the lizards that survived the storms would be those with longer limbs and larger toe pads,” said Kolbe. “And our prediction was supported for the toe pads and the forelimbs. But the survivors had shorter hind limbs, which was a surprise.”
The research team also had a look at the videos they had made in the past of their experiment with the lizards and the leaf blower. After watching the videos, they realized why the lizards who survived had shorter hind limbs.
“When the lizards start to get blown by the wind, their hind limbs lose contact with the vegetation first, so they’re holding on only with their forelimbs,” explained Kolbe. “When they’re perched on vegetation, their hind limbs stick out and catch the wind. It turns out that lizards with shorter hind limbs have an advantage in a hurricane.”
To explain what this has to do with evolution, Kolbe commented: “The event we documented seems to be about natural selection. Some lizards lived, some lizards died. To translate that to evolutionary change, those surviving lizards have to reproduce and those traits – longer forelimbs, larger toe pads – have to be passed on to their offspring. So we’re going back this fall to measure the offspring produced by the surviving lizards.”