Heat tolerance is more variable than cold tolerance across species of Iberian lizards after controlling for intraspecific variation

The widespread observation that heat tolerance is less variable than cold tolerance (‘cold‐tolerance asymmetry’) leads to the prediction that species exposed to temperatures near their thermal maxima should have reduced evolutionary potential for adapting to climate warming. However, the prediction is largely supported by species‐level global studies based on single estimates of both physiological metrics per taxon. We ask whether cold‐tolerance...