Data from: On the correlated evolution of ecological lifestyle and thermal tolerance

The breadth of thermal tolerance delineates the upper (CTmax/Tuc) and
lower (CTmin/Tlc) temperatures relevant to survival and/or persistence of
organisms, and it is a correlate of extinction risk under climate change.
Theory suggests that tolerance breadth evolves with the range of
environmental temperatures. For instance, a narrow tolerance breadth is
classically observed in tropical vs temperate species, and tropical
ectotherms may feature increased extinction risk under climate change due
to the proximity of CTmax and mean environmental temperatures. Here, we
underscore that an organism’s lifestyle influences the extent of thermal
fluctuation in its environment. We predict that subterranean species
feature a narrower thermal tolerance breadth than surface-dwelling
species, as the former evolve under dampened thermal variance. Using
thermal limits data, we test this hypothesis in reptiles, mammals, and
arthropods. Subterranean species (n = 5 – 37 per taxon) featured reduced
tolerance breadths compared to surface-dwelling species, and the
difference was significant in reptiles and mammals; additionally,
subterranean arthropods featured a significantly lower CTmax and
significantly higher CTmin than surface species. Thus, classical theory on
thermal tolerance extends beyond patterns of geolocation to species
lifestyle, where evolution under dampened thermal variance can reduce
thermal tolerance breadth and influence other thermal traits.