Tag: process of evolution

Lamarck contributed to organic evolution through his theory. According to Lamarck, changes in the environment create new needs in the organism for adaptation. Use and disuse of organs and inheritance of acquired characters was also explained by Lamarck. He explained that certain characters which are acquired by the parents can be passed to the offspring. 

This experiment disproves the theory of inheritance of acquired characters, because the tailless condition is an acquired characteristic but it is not inherited by succeeding generations. Lamarck gave theory of inheritance of acquired characters.

Kammerer and McDougall respectively worked on toads and rats and tried to gather experimental evidences to prove Lamarckism, but their experiments were not conclusive evidence for Lamarckism and were criticised on several counts.

Lamarck gave the theory of Inheritance of acquired character. According to which characters acquired by an organism during it's life are inherited by the next generation.

Weismann cut the tails of experimental animals for many generations, yet they were always born with tail. Thus proving that acquired characters (tailless state in this case) are not inherited.

Lamarck theory is also called as Lamarckism. The most popular example used to explain the concept of Lamarckism is the elongated neck of the giraffe. According to this theory, an elongated neck of an African giraffe evolved to reach leaves high in trees. In another example, he proposed that water birds gained long webbed toes for better swimming. Another example of Lamarckism is snakes whose ancestors are lizard like reptiles. They acquired elongated limbless body for their protection.

According to Lamark's principle all the characters that are acquired during the lifetime of an organism are passed on to the next generation. This theory is called as inheritance of acquired characters. However, Wiesmann did not agree with this theory, and proved through the tail cutting experiments on mice that only the changes that take place in the germ cells or the gametes are only passed on to the next generation.

The answer is option C i.e. "Weismann".

• Weismann gave the germ plasm theory which proved that somatic cells have little or no influence in inheritance.
• Darwin only supported Weismann that one’s acquired character is not inherited in the next generation.
• Lamarck gave a hypothesis on the inheritance of acquired characteristics, he proposed the idea of heritability of acquired characteristics.
• While Cuvier did not work in the discovery of inheritance. He discovered the process of the formation of fossils.

Lamarck is best known for his 'Theory of Inheritance' of Acquired Characteristics. If an organism changes during life in order to adapt to its environment, those changes are passed on to its offspring.

The first theory of evolution was proposed by Jean Baptiste de Lamarck Lamarckism proposed,