what is lamarck's theory
theory of use and disuse
and theory of acquited traits
http://www.sparknotes.com/biology/evolution/lamarck/section2.rhtml
Lamarck's theory, also known as Lamarckism, is an obsolete biological theory proposed by Jean-Baptiste Lamarck in the early 19th century. This theory suggested that organisms can pass acquired characteristics or traits to their offspring, leading to evolutionary change over time. Lamarckism proposed two main principles:
1. Law of Use and Disuse: Lamarck theorized that if an organism uses a particular body part extensively, it becomes stronger, while underusing a body part weakens it. This acquired characteristic would then be passed on to the next generation.
2. Law of Inheritance of Acquired Characteristics: According to Lamarck, the acquired traits during an organism's lifetime would be transmitted to its offspring. For example, if a giraffe stretched its neck to reach leaves high up on trees over generations, its descendants would have longer necks.
It is important to note that Lamarck's theory has been widely discredited in modern biology, particularly due to the discovery of genetics and the understanding of how hereditary information is transmitted through DNA. Current evidence supports the theory of evolution by natural selection proposed by Charles Darwin, which offers a more accurate explanation of how species change over time.