Vincent Bels was born in Verviers, Belgium. He completed his PhD at the University of Liège on the topic of behavioural ritualization. Currently, Professor at the Muséum national d'Histoire naturelle de Paris (France), he investigates the evolution of feeding, drinking, locomotion, and display behaviors in vertebrates. His main objective is the integration of behavioral and functional studies to arrive at a more comprehensive understanding of the "Form-Function" complex as it relates to the evolution of organisms.

Anthony Patrick Russell was born in London, UK. He completed his PhD at the University of London in the area of functional anatomy. As a Professor at the University of Calgary he has authored over 300 peer-reviewed scientific articles, 19 chapters, and three books. The continuing focus of his research has been the structure, function and evolution of geckos. Outside the University he has served as President ofthe Canadian Society of Zoologists, and President of the International Society of Vertebrate Morphologists.