Jean Baptist Lamarck was the first person to propose the theory of evolution. He thought that at some point of time in the history the size of giraffe was equal to that of deer. Due to shortage of food material on the ground and to reach the lower branches of trees giraffes started stretching their necks.Because of continuous stretching of neck, after several generations giraffes developed long necks.Such characters that are developed during the lifetime of an organisms are called"acquired characters".Lamarck proposed that these acquired characters are passed on to its offspring i.e, to next generation and proposed the theory of"Inheritance of acquired characters".For example elongation of neck and forelimbs in giraffe.I appreciate him in a high way of scientists towards genetics.