Living in difficult situations: Lizards living in high altitudes have smaller body sizes due to extreme climatic conditions and limited resources

Abstract

The evolution of body size, both within and between species, has been long predicted to be influenced by multifarious environmental factors. However, the specific drivers of body size variation have remained difficult to understand because of the wide range of proximate factors that consistently covary with ectotherm body sizes across populations with varying local environmental conditions. Here, we used a widely distributed lizard (Eremias argus) collected from different populations situated across China to assess how climatic conditions and/or available resources at different altitudes shape the geographical patterns of lizard body size across populations. We used body size data from locations differing in altitudes across China to construct linear mixed models to test the relationship between lizard body size and ecological and climate conditions across altitudes. Lizard populations showed significant differences in body size across altitudes. Furthermore, we found that variation in body size among populations was also explained by climatic and seasonal changes along the altitudinal gradient. Specifically, body size decreased with colder and drier environmental conditions at high altitudes, resulting in a reversal of Bergmann’s rule. Limited resources at high altitudes, as measured by net primary productivity, may also constrain body size. Therefore, our study demonstrates that the intraspecific variation in female lizards’ body size may be strongly influenced by multifarious local environments as adaptive plasticity for female organisms to possibly maximise reproductive ecology along geographic clines.

RETRACTED: Female lizards (Eremias argus) reverse Bergmann's rule across altitude

“…We measured the snout‐vent length (SVL; ±0.01 mm) of collected female lizards in the field station laboratory, after which we released them at the site where they were captured. We collected and measured the body sizes of E. argus female lizards across populations with altitudinal gradients ranging from 30 to 2979 m above sea level (asl), with 60 records from Shidu, 26 from Xingtai, 14 from Jingtai, 36 from Harbin, 31 from Hebei, 25 from Liaoyang, 44 from Chuzhou, 106 from Erdos, and 90 from Gonghe (Deme et al, 2023).…”

“…Data used for this article are available and published online at Data Dryad; https://doi.org/10.5061/dryad.41ns1 rnkm (Deme et al, 2023).…”