Presenter(s): Libardo Gomez − Biology
Faculty Mentor(s): Frances White
Poster 40
Research Area: Natural/Physical Science
The length ratio of the second digit (2D) to the fourth digit (4D) changes with an individual’s exposure to certain hormones prenatally, specifically testosterone (Manning 2002). Scientists therefore use 2D:4D as a proxy for an individual’s testosterone exposure in the uterus; a lower ratio demonstrates higher levels of prenatal testosterone exposure, and a higher ratio demonstrates lower levels of prenatal testosterone exposure (Manning 2002). In primates, testosterone plays a significant role in male-male competition and is therefore higher in males than in females. To collect the most accurate 2D:4D measurements, hands need to be in a fully fleshed stated; due to the limited access to fully fleshed hands, my colleagues and I developed a method to assess accurate 2D:4D ratios post mortem was developed, with results showing articulated bone measurements to have the closest 2D:4D ratio to fleshy skin measurements. Drawing on the many studies that have shown that finger length ratios might be characteristic that can be related to sexual dimorphism (Gillam 2018). We hypothesize that the 2D:4D ratio will be higher in male than female rhesus macaque (Macaca mulatta) and could be used to estimate male from female skeletons. Because rhesus macaques are one of the main non-human primates studied for biological research, this study hopes to expand the body of literature on 2D:4D ratios and prenatal environment effects on bone. Preliminary results show higher male ratios (2D 0.93, 4D 1.14) than in female (2D 0.80,4D 1.02) promising support of this hypothesis.