Free fingers have many obvious advantages on land, such as in locomotion and grasping, while webbed fingers are typical of aquatic or gliding animals. But both amphibians and amniotes -- which include mammals, reptiles, and birds -- can have webbed digits. Scientists now show that during embryo development, some animal species detect the presence of atmospheric oxygen, which triggers removal of interdigital webbing. Continue Reading... Use this thread to discuss the article above. What are your thoughts about Environmental oxygen triggers loss of webbed digits?