Fast facts

• Lizards are a group of animals that require warmth and sunlight to increase their internal body temperature and bolster their metabolism.
• The family of lacertid lizards, sometimes called true lizards, comprises around 340 different species; they are widespread in Europe, Africa, and Asia; these lizards arose and adapted millions of years ago.
• Lacertid lizards exist in the blazing heat of, for instance, the Sahara-Arabian desert, as well as chilly habitats on mountains above 2,000 meters in Europe. One of them, the viviparous lizard, even reaches the Arctic Circle, farther north than any other reptile.

 A new study which delves into lacertid lizards’ origins and evolutionary nature reported that their physiological traits are closely linked to the environmental conditions they live in.

Published in the journal Nature Communications, the study, which was conducted by 45 researchers from 17 countries including NYU Abu Dhabi Postdoctoral Associate Sebastian Kirchhof, found the following:

• Climate change already adversely affects lacertids in montane and cool, moist environments.
• Tropical forest lacertids already operate at body temperatures very close to those of their environment; if temperatures increase, they may not be able to endure.
• Desert lacertids with high thermal preferences and low water loss rates, such as those found in the UAE, so far appear to be less affected.

Miguel Vences, a co-author and professor of evolutionary biology at the Braunschweig University of Technology in Germany, said: "It was amazing to discover how neatly these species are adapted to their environment. Their physiology, size of distribution ranges, species richness, and even mutation rates - everything correlates strongly to the temperatures they experience in the wild."

"We found in these lizards a strong adjustment between physiology and environmental temperature and this likely makes them very sensitive to global warming,” commented the first author of this study Joan Garcia-Porta, researcher at the Centre for Research on Ecology and Forestry Applications, CREAF,  Spain, who is currently at Washington University in St Louis, US.

The study used state-of-the-art DNA sequencing methods and analysis of fossils to reconstruct the evolution of 262 species of lacertid lizards. Glimpsing into the past of lacertids’ evolution shows that many of them originated in warm climates, but have since adapted as the Earth cooled down, and spread into very cold regions over time. 

“On the basis of the new physiology data on thermal preferences and water loss rates, and the new genomic data as a backbone, we were able to better understand how past and present climatic environments experienced by lacertids have shaped the species’ diversity, physiology, and molecular evolution. The locally observed extinction of certain cold-adapted species might be evidence that they are unable to cope with the current pace of climate change,” Kirchhof commented.