What have been the major scientific contributions to our understanding of the evolution of species?Polio Vaccine is considered the biggest Scientific discovery in the history of mankind. How much do people know about scientific discoveries that changed the course of history? On this essay I am going to describe the most important scientific discoveries in the history of evolutionary science from 1800 to the present day, and then conclude which one is the best. To give more information about each scientist I will highlight them and summarise their discoveries. To understand the difference between the ideas proposed by Lamarck and Darwin, I will name both theories and compare them. To give a round end to my essay I will illustrate a timeline to have a clear understanding of the things said before. The evolutionary concepts appeared for the first time in the first Greek writings; for example, in the work of Anaximander and Empedocles. Anaximander proposed that animals could be transformed from one type to another, and Empédocles speculated that they could be made up of various combinations of pre-existing parts.However, later it was prevented that evolutionary theories developed and challenged the belief of special creation for about fifteen centuries, due to the restrictive influence of religions. Cuvier saw organisms as integrated wholes in which each part’s form and function were integrated into the entire body. No part could be modified without impairing this functional integration. Cuvier did not believe in organic evolution, he thought that organisms were functional wholes, any change in one part would destroy the delicate balance. In the early 19th Century, the French naturalist Jean-Baptiste Lamarck presented a new evolutionary theory. This theory, known as ‘The Inheritance of Acquired Characteristics’, was put-down at the time and thoroughly negate in the 20th Century. The father of the modern theory of evolution was Charles Darwin. In 1859 the first edition of his On The Origin of The Species was published. The naturalist Alfred Wallace had also reach the idea of natural selection at the same time as Darwin, however, his different view from Darwin’s, was insufficient to account for the origin of man, but his discovery to had been approved.Darwin’s and Lamarck’s might sound equal, but in reality, both theories are quite different:Lamarck’s theory held that species adapted themselves with changes in response to changes in their environment. One notable example quoted by him was the case as it might exist with respect to Giraffes. Darwin’s theory, otherwise,defended natural selection and survival of the more capable. He defended that when environment underwent changes, the species affected by these changes underwent changes in response to changes in the environment.Mendel developed a theory that completed the missing link in Darwin’s argument. Gregor Mendel was an Augustinian monk who accomplished a long series of experiments with peas in the garden of his monastery. His theory, published in 1866, formulated the fundamental principles of the theory of heredity, and it is still used nowadays.In the 1920s and 30s, theoretical geneticists including Ronald Fisher and John Haldane in Britain and Sewall Wright in the United States, used mathematical arguments to backing natural selection and contributed to the deterioration of mutationism. They also contributed a theoretical plan for the integration of genetics into Darwin’s theory of natural selection. Ernst Mayr collaborated on defining the modern synthesis of evolutionary theory, proposing the “Biological Species Concept.” In particular, his work on species and speciation helped scientists making progress and mechanisms of evolution from one species to another. Crick and Watson, together with Maurice Wilkins, won the 1962 Nobel Prize in Medicine. This famous prize was given to them for discovering the structure of DNA. This was one of the symbolic scientific discoveries of the 20th century.