The theory of Lamarck was rejected. He gave theory of acquired characteristics. Lamarck's mechanism for evolution involved the inheritance of acquired traits. He believed that traits changed or acquired over an individual's lifetime could be passed down to its offspring. He gave an example that Giraffes that had acquired long necks would have offspring with long necks rather than the short necks their parents were born with. This type of inheritance, sometimes called Lamarckian inheritance, has since been disproved by the discovery of hereditary genetics.
