While hiking on some small islands in Lake Superior, you stumble across a small frog. Thinking about your respective evolutionary histories, what is a likely homology between you and this animal: Number of limbs External fertillization Amniotic egg Four-chambered heart Live birth Solution ANS: A. Number of limbs. Explanation: According to the evolution, comparative anatomy of limb bone structure (pentadactyl ,5 digit) is same in most vertebrates. It is called homology. Homologies clearly indicate the phenomenon of common ancestry. Like humans frogs also contains same bone structure. They are…. Arms: Like Human arms, frog front leg bones are called as humerus, radius and ulna (radius and ulna are fused into one bone). Legs: Like Human legs, frog femur supports its upper leg and lower leg bone (tibia and fibula, are fused). And also frog contains two scapulae (shoulder blades), and clavicles (collarbones) like human..