Katharina Valero, a lecturer in Ecology and the Environment at the University of Hull with 10 years expertise in studying the genetics of environmental adaptation in cold-blooded vertebrates, said: "The story of non-tropical lacertids is one of persistence against cold. We found no precedent in their evolution to cope with either heat or with dry conditions for millions of years. Achieving this in our rapidly warming climate may present quite a challenge for them.”
Joan Garcia-Porta, researcher at the Centre for Research on Ecology and Forestry Applications, CREAF, Spain and currently at Washington University in St Louis, USA, the first author of this study, said: "We found in these lizards a strong adjustment between physiology and environmental temperature and this likely makes them very sensitive to global warming.”
Confirmation of the study's hypothesis comes from the perhaps most cool- and moist-loving viviparous lizard.
Barry Sinervo, a professor at the University of California at Santa Cruz who has been studying lizard declines for over 10 years, said:"Populations in the Pyrenean Mountains where environmental temperatures come close to their preferred temperatures are already extinct – a presage of what might happen with other lizards."
The study used state-of-the-art DNA sequencing methods and analyses of fossils to reconstruct the evolution of 262 species of lacertid lizards. According to Iker Irisarri, a researcher at the Spanish Research Council CSIC in Madrid, who contributed to these analyses: "These animals in Europe have been the focus of hundreds of studies over the last years. Our new genomic analyses finally ascertained how they relate to each other in evolutionary terms, and when they originated."
Miguel Vences, a co-author and professor of evolutionary biology at the Braunschweig University of Technology, 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."
Miguel-Angel Carretero, a lizard specialist at CIBIO institute, Portugal, said: "The mechanisms by which these lizards decline are complex, but we start to understand them better. Warmer temperatures also mean lower humidity, and climate change forces these lizards being active in dry environments that they cannot cope with."