Materials and Methods: Ninety maxillary study models (30 from each group including males and females) were examined in the age group ranging from 18 to 25 years. The palatal rugae pattern was analyzed for shape.
Results: After analyzing the rugae patterns among the groups, the most common pattern was the wavy pattern (53.57%) followed by curved (18.22%) and straight (13.66%). The least was circular (1.3%). When compared between sex, the most common pattern was found to be wavy (male - 54.3% and female - 53.09%), while the curved pattern was more common among the females (21.09%) than males (13.97%). The straight pattern was more common among the males (18.8%) than females (10.18%). The least common pattern was found to be the circular in both sexes which accounted for around 1%.
Conclusion: This study shows no two palates are identical in terms of their rugae pattern. Palatal rugae possess unique characteristics as they are absolutely individualistic. Study also confirms that the "wavy" type of palatal rugae pattern was the most predominant among these three populations.
PRESENTATION OF THE HYPOTHESIS: The hypothesis that is presented consists of two parts. First, that shell ornamentation is the result of sexual selection. Second, that such sexual selection has caused the divergence in shell shape in different species.
TESTING THE HYPOTHESIS: The first part of the hypothesis may be tested by searching for sexual dimorphism in shell ornamentation in gonochoristic snails, by searching for increased variance in shell ornamentation relative to other shell traits, and by mate choice experiments using individuals with experimentally enhanced ornamentation. The second part of the hypothesis may be tested by comparing sister groups and correlating shell diversity with degree of polygamy.
IMPLICATIONS OF THE HYPOTHESIS: If the hypothesis were true, it would provide an explanation for the many cases of allopatric evolutionary radiation in snails, where shell diversity cannot be related to any niche differentiation or environmental differences.