Study of Sexual Dimorphism in Second-to-fourth Digit Length Ratio (2D: 4D) in the Green-Bellied Lizard (Darevskia cholorogaster) from Iran

Sexual dimorphism in digit ration is related to genetic differences between species in response to prenatal exposure to hormones. In this study, the development of tetrapod digits, preliminary the ratio between the length of digit II and IV (2D: 4D) was investigated in 34 samples of Darevskia cholorogaster in the North of Iran. The results showed no significant differences between sexes in any digit length. The digit ratio 2D: 4D was different between males and females in which the females had greater 2D: 4D in forelimb than the males. However, this difference was not significant. Sexual dimorphism in 2D: 4D, 3D: 4D and 2D: 3D ratios for the male and female showed no correlation within sex. Our results supported a genetic pattern seen in humans and most mammals, inconsistent with basic genetic pattern in reptiles. We concluded that the digits ratios observed in D. cholorogaster could be referred to microhabitat use by this species on different surfaces, besides basic genetic pattern and other ecological effects as foraging and mating.