Geckos are known for sticky toes that allow them to climb up walls and even hang upside down on ceilings. A new study shows that geckos have gained and lost these unique adhesive structures multiple times over the course of their long evolutionary history in response to habitat changes. “Scientists have long thought that adhesive toepads originated just once in geckos, twice at the most,” says University of Minnesota postdoctoral researcher Tony Gamble, a coauthor of the study. “To discover that geckos evolved sticky toepads again and again is amazing.”
The researchers found that sticky toes evolved independently in about 11 different gecko groups. Repeated evolution is a key phenomenon in the study of evolutionary biology. A classic example is the independent evolution of wings in birds, bats and pterosaurs. It represents a shared solution that organisms arrived at separately to overcome common problems.
The amazing clinging ability of Gecko toes has inspired engineers to develop biomimetic technologies ranging from dry adhesive bandages to climbing robots. “Gaining a better understanding of the complex evolutionary history of gecko toepads allows bio-inspired engineers to learn from these natural designs and develop new applications,” says co-author Anthony Russell, of the University of Calgary. While scientists have a good understanding of how geckos stick at the microscopic level, they are just beginning to understand how geckos use their adhesive toepads to move around complex environments in the wild. Learning how gecko toepads have evolved to move in nature is an important step in developing robotic technologies that can do similar things.
Read more at PhysOrg