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Abstract Present study was conducted to determine the prevalence of tongue rolling trait in the population of district Sargodha Pakistan. We also tested the hypothesis that tongue rolling is not genetically controlled but people learn this trait with age and experience. To record the prevalence of rollers and non rollers data of 1734 individuals (682 males and 1052 females) was collected. To study the effect of age and experience on tongue rolling data of school students of two different age categories was collected. Observed frequencies of roller males and females were 68.32% and 45.82% respectively. Significantly higher number of roller males was recorded in age category B (12-13 years) compared to age category A (7-9 years). However difference was non-significant in the two age categories for females. We also recorded 19 % roller offspring from families in which both parents were non rollers. Results of the study indicate that tongue rolling is a complex trait which might involve non-genetic influence or may be controlled by multiple genes.
Keywords: Tongue rollers complex trait genetic traits.
Most of the genes follow Mendelian pattern of inheritance. However inheritance of some traits involves complex genetic phenomena such as co- dominance sex-linked genes and polygenic inheritance (Batul 2010). Tongue rolling is the genetic trait quoted very frequently by biologists to demonstrate basic genetic principles (McDonald 2011). The ability to roll tongue is considered to be due to the involvement of a dominant gene (R). People having recessive (r) allele are unable to roll their tongues (Hsu 1948). Liu and Hsu (1949) reported the involvement of recessive gene in tongue rolling.
Present study was aimed at recording the prevalence of rollers and non rollers in the population of district Sargodha Pakistan. Komai (1951) and Whittinghill (1970) claim that tongue rolling is not genetically controlled but people learn this trait with age and experience. In the present study we have also tested this hypothesis by studying the tongue rolling trait...