Quadrupeds (or tetrapods) is the name given to four-footed land-dwelling vertebrates. This general classification includes amphibians, reptiles and mammals. The Darwinists' explanation is that quadrupeds evolved from fish. However, this claim is physiologically and anatomically untenable-and also, has no foundation in the fossil record.
In order for a fish to adapt to life on dry land, it would have to undergo tremendous changes in its respiratory system, excretory system and skeletal structure. Its gills would have to be supplemented by lungs; its fins would have to acquire sturdiness capable of bearing the weight of its body. Kidneys to dispose of bodily wastes would need to form, and its skin would have to acquire a structure to prevent loss of moisture.