Final answer:
A four-chambered heart is advantageous because it ensures the efficient movement of oxygen throughout the body, maintains separation of oxygenated and deoxygenated blood, and supports the high metabolic demands of mammals and birds with double circulation.
Step-by-step explanation:
The advantage of a four-chambered heart over a three-chambered heart is in its ability to efficiently move oxygen around the body. Because the oxygenated and deoxygenated blood are separated, the four-chambered heart supports double circulation, efficiently supplying oxygen-rich blood to body tissues and organs. In contrast, a three-chambered heart, such as that found in amphibians, allows for some mixing of oxygenated and deoxygenated blood, which can reduce the efficiency of oxygen delivery.
The right side of the heart pumps blood to the lungs to get oxygen, and the left side pumps the oxygenated blood to the rest of the body. This design is crucial for animals with high metabolic demands, such as birds and mammals. These groups exhibit convergent evolution, having independently evolved the same adaptation of a four-chambered heart. The separation of blood flows allows the body to respond more effectively to the need for rapid movement or high energy activities.