Describe the evolutionary change in the pattern of heart among the vertebrates.
Explanation The heart is the principal organ present in the circulatory system. The evolution of the organs in the process of acquiring changes to attain its maximum efficiency. Heart of the vertebrates has attained its evolutionary changes in the various stages as follows. In the case of vertebrates like fishes, the heart contains one atrium and one ventricle. A single system of heart present in the fishes. In the case of vertebrates like amphibians, the heart contains two atria and a single ventricle. It has a three-chambered system of the heart. The evolutionary development of the heart from fishes to amphibians is observed. In the case of reptiles, the heart is a three-chambered structure along with the presence of a septum. There is a slight difference compared to amphibians. The vertebrates like mammals and birds possess a four-chambered heart with two atrium and two ventricles. This is the complex form of the heart involving the many arteries and blood vessels in it. Final Answer The heart of the vertebrates had many evolutionary changes in acquiring the four chambered cardiac system. This evolutionary change is noticed in organism like fishes, amphibians, reptiles, mammals and birds.
