2.2 Environmental factors
For the extraction of environmental variables (i.e., elevation, mean annual temperature, temperature seasonality, mean annual precipitation, precipitation seasonality, net primary productivity) for each population of lizards, we used the Raster package in R (Hijmans and Etten, 2012). We elected to use the annual mean temperature and precipitation because these climate variables represent the mean yearly climate conditions that can influence some life-history traits of lizards across populations (Volynchik, 2014; Anderson et al., 2022). Thus, tested for a relationship between body size variation across populations of female lizards and these climatic variables (Volynchik, 2014; Deme et al., 2022a). Furthermore, temperature seasonality and precipitation seasonality were used because these variables represent the annual variation in climate conditions, with lower annual variability indicating more stable climates and greater active time for scouting for resources (Meiri et al., 2013; Meiri et al., 2020). To extract these environmental factors, we used the highest resolution within a 2.5 arc minute resolution grid (1 × 1 km) from the Worldclim2.1 database (http://www.worldclim.org; accessed on 30 August 2021). For the net primary productivity, we extracted data using the highest resolution within 2.5 arc minutes from the Earth’s land surface areas (http://chelsa-climate.org/; accessed on 2 January 2022). Finally, our extracted environmental (climate) variables were set at WGS 1984 and projected to UTM Zone 20N geographic spatial reference.