Fingerprints Hold Clue to Ancestry

A more rigorous analysis of fingerprints may provide information on a person’s ancestry. Reuters

Each individual's fingerprints are unique—the tiny loops, ridges and whorls on the epidermis are even more distinctive than a person's DNA and are one of the best ways we have of identifying a person today. New research has found these tiny etchings, known as dermatoglyphics, can also serve as way to trace an individual's ancestry.

For some time, anthropologists and forensic scientists have used fingerprints to learn more about identity, but the two disciplines tend to focus their analyses on different details. Anthropologists examine what's known as Level 1 details, a close look at the pattern types and ridge counts. Forensic scientists focus on Level 2 details, fingerprint "minutiae," or the specific variants of fingerprints like the shape and direction of ridges and where they split, known as bifurcation.

A study published recently in the American Journal of Physical Anthropology is one of the first joint efforts to bridge the gap in the two fields by examining sex and ancestry with a look at pattern type variation of Level 2 detail. The study involved 243 individuals, including 61 African American women, 61 African American men, 61 European American women and 60 European American men. The researchers looked specifically at fingerprints from the right index finger.

While they weren't able to detect any notable variations in the fingerprints of men versus women, the researchers did find Level 2 differences in the fingerprints of African-American people versus those of European-American descent.

Ann Ross, a professor of anthropology and co-director of the Forensic Sciences Institute at North Carolina State University and co-author of the study, says the findings indicate that anthropologists should make use of Level 2 fingerprint details to enrich their understanding of global population structures. However, the concept would need to be tested on a larger and more ethnically diverse sample of people to determine its reliability, Ross says.

Dermatoglyphics are human traits that begin to form as early as the sixth or seventh week of gestation. The shapes and patterns of fingerprints are determined by factors including the size of volar, or finger pads, as well as stress from hand use and physiological environment. But they are so distinctive that there's only one in several billion chances that your fingerprints will match someone else's exactly.

A growing body of research has found that fingerprints are also a powerful tool for learning more about a person beyond whether he or she was at the scene of a crime. Studies have found there are some patterns, shapes and repetitions of fingerprint patterns that are unique to certain diseases and health conditions. One study suggests people with Alzheimer's disease have more ulnar loops (loop patterns that flow toward the little finger) and fewer ridges and arches. Another study, published in the American Journal of Genetics, found that women with breast cancer were more likely to have a pattern of six or more whorls (coils or spirals) on fingers than women without the disease.