Body size and substrate use affect ventral, but not dorsal, brightness evolution in lizards

• DOI: 10.1093/evolut/qpad065
• Publication Date: 2023-04-19T18:27:16Z
• Authors: Jonathan Goldenberg; Federico Massetti; Liliana D’Alba; Matthew D Shawkey
• Keywords: Affect

Abstract Substrate properties can affect the thermal balance of organisms, and colored integument, alongside other factors, may influence heat transfer via differential absorption reflection. Dark coloration lead to higher could be advantageous when substrates are cool (and vice versa for bright coloration), but these effects rarely investigated. Here, we examined effect substrate reflectance, specific capacity (cp), body size on dorso-ventral brightness using 276 samples from 12 species cordylid lizards distributed across 26 sites in South Africa. We predicted, found, that ventral colors occur more frequently low cp (i.e., drier, with little energy needed temperature change) substrates, especially larger body-sized individuals, possibly better modulate surrounding environment. By contrast, dorsal was not associated nor any property, suggesting selection pressures than thermoregulation. Ancestral estimation evolutionary rate analyses suggest rapidly differentiated within Cordylinae starting 25 Mya, coinciding an aridification period, further hinting at a thermoregulatory role colors. Our study indicates have direct shaping evolution ectotherms.