Question

Differentiate between Lamarckism and Darwinism through the example of giraffe.

Answer 1

	Lamarckism	Darwinism
1.	According to Lamarck, giraffes had short necks in the ancestral stage. Due to scarcity of grass, they stretched their necks to reach leaves on tall trees.	According to Darwin, the ancestors of giraffes showed variation in neck length, and these variations were heritable.
2.	Continuous use and stretching of the neck caused it to become longer during their lifetime. The neck of the offspring increased in length and was also stretched to feed on leaves of tall trees.	Due to the struggle for existence, giraffes with longer necks were better adapted and survived better. Due to natural selection, offspring with long necks increased in number, while those with short necks gradually disappeared.
3.	The acquired long neck was passed to the next generation. Over generations, the neck continued to increase in length, resulting in the evolution of the long neck in modern giraffes.	Giraffes with favourable variations reproduced more successfully and passed these variations to their offspring. Thus, only giraffes with longer necks survived, resulting in the evolution of the long-necked giraffe.