Hurricanes are immensely destructive and they’re predicted to get more severe due to climate change. In 2017, we were surveying Anolis scriptus populations in Turks and Caicos just before Hurricane Irma hit the islands. We realized that, just from being in the right place at the right time, we had a unique dataset that might inform whether Hurricanes can be agents of natural selection. Other extreme climate events have been shown to have evolutionary implications. So, we revisited the islands six weeks (and two hurricanes) after our first visit. We found significant shifts in both the limb dimensions and toepad surface area of the surviving lizards relative to the populations we’d sampled before the storms. These trait shifts, we think, may have given those lizard survivors a clinging advantage during the hurricane’s strong winds.
The study was published in Nature and I’ve written more about the background of the paper here.
That study left us with some important questions though: First, what did the hurricane-selection mean for the next generation of lizards on Turks and Caicos? And second, is this pattern with hurricanes part of a larger trend across other lizard species?
We answered these questions in a study published in 2020 in the Proceedings of the National Academy of Sciences, USA.
First, we revisited the populations on Turks and Caicos a year later and surveyed the offspring of the hurricane survivors. We discovered that the toepad surface area of the offspring were identical to those of the hurricane survivors, and still larger than those toepads of the pre-hurricane populations. In other words, the hurricanes had a trans-generational effect on these lizards in Turks and Caicos.
In order to determine whether the effects of the hurricanes could be detected at larger geographical scales, we collected toepad data from populations and species all across the Caribbean with the hypothesis that populations and species more often hit by hurricanes would have relatively larger topads. Indeed, that’s exactly what we found.
We’ve been fortunate to have some terrific videos made about the research:
For additional press about the research I recommend articles by Ed Yong in The Atlantic, Joshua Sokol at the New York Times, Elaina Zachos at National Geographic, Joshua Rapp Learn at Smithsonian Magazine, Kat Eschner at Popular Science, Andrew Freedman at Axios, Seth Borenstein at The Associated Press, and an interview with Marco Werman on PRI’s The World.
Here also is a video from National Geographic:
And here is one last (hilarious) video put together by the French CNRS: