Evolution In Action: City-Dwelling Forest Lizards Adapt Their Footwear

While the urban environment grows, wildlife finds ways to survive. Unnoticed by the majority of Puerto Ricans, a little, brownish lizard emerges from the forests and develops in order to dominate the city.

The researchers who researched the pioneer reptile discovered that it has evolved larger legs for running across the wide expanses of the city and that its paws have become used to the smooth surfaces of the walls.

The Research That Was Published In The PNAS Journal Is An Illustration Of Evolution At Work

According to the researchers, there are certain creatures that survive or even thrive in urban surroundings, despite the fact that urbanisation has significantly altered global landscapes and harmed biodiversity.

Previous studies have shown, for instance, metabolic alterations brought on by various city diets or modifications in the body’s resilience to cold or heat.

According to Kristin Winchel, the main author of the research, “Urbanization impacts almost two-thirds of the world and is anticipated to worsen, so it’s crucial to understand how species may adapt to a changing habitat.”

Winchell and her colleagues sought and grabbed 96 lizards of the species Anolis cristatellus while running on the asphalt. They then compared the anatomical and genetic makeup of lizards residing in the forest with populations in the island’s capital San Juan and two other towns.

33 genes that seem to be strongly associated with city living were discovered via genetic comparison.

The results of the morphological study revealed that city lizards often have longer legs, which, in Winchell’s opinion, makes it simpler for her to sprint, for instance, on the scorching asphalt of open-air parking lots.

In addition, city lizards have thicker, bigger “pads” of unique scales on their paws that enable them to clamber over steep surfaces. The minuscule structures of the paw harness the feeble “Van der Waals” forces to attach, much as in other lizards like samamides.

According to Wauter Hafwarek, an evolutionary ecologist at the Free University of the Netherlands who was not involved in the research, the study provides compelling evidence of a genetic signature connected to adaption to the new environment.

The next step should be to check for any limiting factors in adaptive reflexes, according to Huffware, who has examined a species of frog that altered its amorous call in the urban environment. He also recommends looking at the connection between morphology and reproductive behaviour.

The immune system and metabolism are two areas where some of the genes have been discovered. We have evidence that city lizards are damaged more often and have more parasites, so alterations in immune function and wound healing would make sense, adds Wincell, however additional research on these genes is necessary to determine what this result implies.

Additionally, because city lizards consume human food, it’s probable that their metabolism has changed.