Phylogenetic evolution of the heart

In 1859 Charles Darwin in his “The Origin of Species” formulated three facts that explain the principle of evolution: the presence of a common ancestor, the existence of advantageous genetic mutations for survival and the elimination of unfavorable ones or Natural Selection. The embryological development of the mammalian heart improves the need for external oxygen uptake, transport and release in the tissues, which exists in all multicellular living beings from the most primitive and enables the function of all organs and systems. In invertebrates, such as insects, arthropods and molluscs, the open circulatory system reaches a development similar to that of human Carnegie stages 10-13: endocardial tubes, straight tube, or early stages of the bulboventricular loop. In vertebrates, the closed system of fish develops hearts with three and four chambers equivalent to the torsion phase of the loop in mammals, or the fifth week of human embryonic development, with a model closer to that of mammals appearing in reptiles with differences such as the incomplete septation of the ventricles and the development of two aortic trunks in crocodilians. Birds and mammals have reached a similar degree of embryonic development of their hearts, with four septate chambers, the same as the Cono Truncus one, and which separate the systemic and pulmonary circulation. All the embryological development of the human heart is completed between days 20 and 60 of gestation, concluding in the fetal phase its growth together with the rest of the organism.