→ Lamarck's theory is "Theory of Inheritance of Acquired Traits".
→ Naturalist Lamarck said that, living forms evolved, they evolved organs, but they were communicated through the use and disuse of those organs.
→ Development of organs is created and maintained in organisms under environmental pressure.
→ Lamarck gave the example of giraffe.
→ Giraffes adapted by lengthening their necks to reach edible leaves of tall trees.
→ This acquired trait of long neck was inherited in its subsequent generations.
→ Over the years the giraffe gradually acquired a long neck.
→ In this way, the characteristics acquired by the organism are inherited by its offspring.
→ In this way the development of the trait increases or decreases from generation to generation.