Pangesesis is incorrect because reproductive cells are not composed of contributions from body cells and changes in body cells do not influence egg and sperm cells. All characteristics are inherited from the father. All characteristics are thus inherited from the mother. Based upon their observations with ornamental plant breeding, scientists in the nineteenth century realized that both parents contribute to the characteristics of offspring. Since the hereditary material is inseparable, the population should reach a uniform appearance after many generations.
Some traits are absent in one generation and present in the next.
Modern genetics began in the 1860's with the experiments of an Augustinian monk named Gregor Mendel who discovered the fundamental principles of inheritance.