Which of the following is not a morphological variation

"Tongue rolling" is not a morphological variation. Morphology refers to the study of the form and structure of organisms, and morphological variations refer to differences in the physical characteristics of individuals within a species. The shape of the nose, color of the skin, color of the eyes, and ear lobe are all examples of morphological variations that can be observed in humans. However, the ability to roll one's tongue is not a morphological variation because it is a function of the muscles in the tongue and not a physical characteristic of the tongue itself. Some people are able to roll their tongues, while others are not, but this difference is not related to the structure or form of the tongue. Instead, it is a genetic trait that is inherited independently of other physical traits. Therefore, tongue rolling is not a morphological variation.