Two hurricanes forced a lizard to change its grip on branches

The Story in Brief

Scientists from Princeton and Harvard surveyed Turks and Caicos anoles on Pine Cay and Water Cay four days before Hurricane Irma struck on 8 September 2017 with sustained winds of 265 km/hr. They measured limbs, toes, toepads and took tissue samples. Two weeks later Hurricane Maria arrived on 22 September with 200 km/hr winds. The storms flattened vegetation and killed many lizards. Six weeks after the storms, returning researchers found surviving Anolis scriptus had longer forelimbs, shorter hind legs, shorter hind toes, and larger front and back toepads compared with pre-storm measures; however the fourth hind toe was shorter. A Current Biology study reported five genes involved in muscle and skeletal development rose in frequency after the storms on those islands. One gene, hs6st1, was linked to the shorter fourth toe: CRISPR knockout of hs6st1 in brown anole (Anolis sagrei) embryos produced shorter fourth toes and thinner cartilage. Wind-tunnel tests at 118 km/hr showed front limbs bore most of the grip and that shorter first toe bone increased hold time. Researchers emphasise that extreme weather can alter wild populations.

The Indian Opinion

Some coverage used colourful phrases such as “evolution on steroids”; this is a vivid metaphor but risks overstating the findings. The studies document rapid morphological and genetic change in two small island populations after two hurricanes, and gene-editing in a related species supports a causal role for hs6st1 in fourth-toe development. At the same time, the reported results come from specific islands, species and experimental settings, and the article does not give detailed sample sizes or long-term population trajectories. An ordinary reader should be cautious about generalising these findings to other species or regions; the work is a clear example of rapid change under extreme weather, but uncertainty remains about wider or lasting effects.

Original article: Hold tight! How two hurricanes forced a lizard to change its grip (www.thehindu.com)

This story was summarised and commented on by AI from the source linked above.