Transcript Slide 1
Investigation of the Inheritance of Fingerprint Characteristics By: Sara Henderson with Marietta Wright Waynesburg University Department of Biology Abstract Dermatoglyphics, or the study of fingerprints, is one of the most prominent fields in Forensic Science. Many people believe fingerprints are only significant for the identification of criminals. For more than one hundred years, fingerprints have been collected, observed, and tested as a means of unique identification of persons. Minimal research has been conducted on the inheritance of fingerprint patterns and Total Ridge Count (TRC). In this study, fingerprints were taken from twenty-four individuals, two groups of twelve, which were separated into four groups of three. These groups were three generations of individuals who are related and three generations of individuals who are not related (the control group). It was determined that related individuals had a very similar Total Ridge Count and pattern types versus individuals who were not related, showing little to no similarities. This study demonstrated that Total Ridge Count and fingerprint patterns could be proven to be inheritable traits and could be used as identification in the Forensic Science field. Introduction The use of fingerprints is one of the oldest biometric measures of identity, but weren't used as a method for identifying criminals until the 19th century. Human fingerprints are part of an individual’s phenotype, arising from the interaction of the individual’s genes and the developmental environment in the uterus. In dermatoglyphics and the field of Forensic Science there are three main types of fingerprint patterns used for classification; loops, whorls and arches. Loops constitute between 60 and 70 percent of the patterns encountered. Another type of pattern, whorls, constitutes about 25 to 35 percent of the patterns encountered. Arches represent only about 5 percent of the fingerprint patterns encountered. Scientists observe the arrangement, shape, size and number of lines in these fingerprint patterns to distinguish one type from another. Fingerprints are not only classified by their pattern, but also by the ridge count. Total Ridge Count (TRC) is the sum of the ridges for all 10 fingers. To determine the TRC for a single print, the type of pattern must first be determined. The number of ridges for each particular pattern, is determined by counting along the triradius to the core. Introduction Continued Since arches do not contain a triradius, the TRC is 0. For whorls, the ridges are counted along all triradii, with the largest number being designated as the TRC. Aims o Observe fingerprint characteristics between related individuals and unrelated individuals (control). o Compare Total Ridge Counts and fingerprint patterns. o Determine whether TRCs and fingerprint patterns are similar between individuals from one generation to the next generation. Methods o Take all ten digit fingerprints from 24 individuals o Classify each fingerprint into the loop, arch or whorl category. o Record each ridge count for all ten fingers to come up with TRC. Results Continued Results Continued Table 1. Pattern Participants General Population Loop 66.66% 68.9% Whorl 29.17% 26.1% Arch 4.1% 5.0% Table 1. Comparison of the percentage of fingerprint patterns from the participants in this study versus the general populations fingerprints. Table 2. Ridge Count (Related) Ridge Count (Not Related) 1A 149 1D 68 1B 153 1E 123 1C 147 1F 116 2A 127 2D 110 2B 133 2E 200 2C 134 2F 177 3A 3B 168 175 3D 3E 180 185 3C 161 3F 153 4A 121 4D 189 4B 130 4E 87 4C 119 4F 182 Table 2. The Total Ridge Count (TRC) for all 24 individuals. Labeled with letters and numbers for confidentiality. 1A, 1B, and 1C are the first group of related individuals and 1D, 1E, and 1F are the first group of individuals who are not related. Results 1A 1B 1C 2A 2B 2C 1A 1B 1C 3A 3B 3C 1A 1B 1C 4A 4B 4C P-value .0028 P-value .0142 P-value .0023 2A 2B 2C 3A 3B 3C 2A 2B 2C 4A 4B 4C 3A 3B 3C 4A 4B 4C P-value .0013 1D 1E 1F 2D 2E 2F P-value .1180* 1D 1E 1F 3D 3E 3F P-value .0011 1D 1E 1F 4D 4E 4F P-value .1346 2D 2E 2F 3D 3E 3F P-value .7376 P-value .0243** 2D 2E 2F 4D 4E 4F P-value .8314 P-value .2470 3D 3E 3F 4D 4E 4F P-value .5918 Figure 3. The P-values of the related individuals is considered to be very statistically significant. The P-values of the individuals who were not related is considered not statistically significant. *P-value in related individuals which was not statistically significant ** P-value in unrelated individuals which was statistically significant Conclusion o Fingerprints of related individuals showed significantly similar characteristics such as Total Ridge Count and patterns. o Fingerprints of individuals who were not related showed little to no similarities. o A more concrete conclusion could be determined with a larger population. o Further studies could be done with genes to conclude if the fingerprint characteristics are ultimately inherited. Acknowledgements Figure 1. The percent of individuals with the specific fingerprint pattern. http://www.akspublication.com/paper04_jul-dec2008/Figure1.jpg Figure 2. The TRC of all 24 individuals. I would like to thank Waynesburg University’s Biology Department for the supplies to conduct my research. I would also like to thank Marietta Wright for all her help and suggestions and Dr. Chad R. Sethman for his guidance. Lastly, I would like to thank all the participants that willingly gave their fingerprints. I would of not been able to do the research without them.