Extreme positive allometry of animal adhesive pads and the size limits of adhesion-based climbing.

摘要: Organismal functions are size-dependent whenever body surfaces supply volumes. Larger organisms can develop strongly folded internal for enhanced diffusion, but in many cases areas cannot be so that their enlargement is constrained by anatomy, presenting a problem larger animals. Here, we study the allometry of adhesive pad area 225 climbing animal species, covering more than seven orders magnitude weight. Across all taxa, showed extreme positive and scaled with weight, implying 200-fold increase relative from mites to geckos. However, allometric scaling coefficients systematically decreased taxonomic level were close isometry when evolutionary history was accounted for, indicating substantial anatomical changes required achieve this limited phylogenetic constraints. Using comparative approach, found departure almost exclusively caused large differences size-corrected between arthropods vertebrates. To mitigate expected decrease weight-specific adhesion within closely related taxa where isometry, data several suggest pads' strength increased The combination adjustments distantly groups helps explain how pads has evolved animals varying over Our results illustrate size limits adhesion-based climbing, profound implications large-scale bio-inspired adhesives.