Pattern Intensity index, Dankmeijer Index, Main line formula, Main line index.

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1 Course Name: PHYSICAL ANTHROPOLOGY Paper No. & Title: B.A. / B.Sc. (Honours) 5 th Semester (Practical) Topic No. & Title: (7/17) Pattern Intensity index, Dankmeijer Index, Main line formula, Main line index. Introduction: The skin on the fingertips and palmar and plantar surfaces of man is not smooth. It is grooved by curious ridges, which forms a variety of configurations. These ridge configurations have attracted the attention of laymen for millennia. The anatomist Bidloo provided a description of ridge details in the 17th century. Since then, Anthropologists, Biologists, and Geneticists have added additional

2 information. For the last century, especially law enforcement officials have utilized the fact that each individual s ridge configurations are unique as means of personal identification. More than five decades ago, monograph on epidermal ridges was published by Cummins and Midlo (1943/1961). This classic provided interesting information on historical development of the scientific study of epidermal ridges and invaluable suggestion regarding recording and analysis of epidermal ridge configurations. Cummins and Midlo (1926) also coined the term dermatoglyphics (derma = skin, glyphics = curving). Dermatoglyphics (derma, skin + glyphic, carve) is the study of the ridge patterns of the skin of the fingers, palms, toes and soles. The human body is covered with hairs and sebaceous (oil) glands except the palmar and plantar regions which are continuously corrugated with narrow ridges. The ridges make certain patterns. Dermal ridge differentiation takes place early in fetal development. The resulting ridge configuration are genetically determined and influenced (or modified) by environmental factors. There is paucity of knowledge concerning the development mechanism. The idea Bonnevie (1924) reported was that small pads would result simple pattern (arch), while more prominent pattern would tend to develop large and complex ridge configuration (whorls and loops). Epidermal ridge patterns are complete only after the sixth prenatal month, when the glandular folds are fully formed. There are a number of methods for recording dermatoglyphics. The methods vary in their requirements for equipments, time and experience and in the quality of the prints produced. The dermatoglyphics are usually recognizable by the naked eye. Permanent impression or prints are necessary for quantitative analysis of dermatoglyphics. There are some standard techniques of recording dermatoglyphics on the basis of choice of investigators, based on preference of the features. For example, INK METHOD: One of the best known and mostly used dermatoglyphics printing methods utilizes printers ink and a good quality of paper. INKLESS METHOD: The most common method for obtaining prints makes use of a commercially available patented solution and specially treated, sensitized paper. TRANSPARENT ADHESIVE TAPE METHOD: Use of transparent adhesive tape as a means of obtaining prints of dermatoglyphics pattern. The first individual to use fingerprints on a large scale was Sir William Herschel, a British government official living in India during the second half of the nineteenth century. Sir William Herschel made the natives place their fingerprints (in some cases, their entire handprint) on legal

3 documents. Subsequently, Sir William Herschel realized that fingerprints could be a general method of identification for both criminal and civil affairs. He introduced fingerprint identification on a wide scale in his province in India, but failed to attract interest back in England. At approximately the same time, Henry Faulds, a Scottish doctor living in Japan began collecting fingerprints. By chance, he was asked to help investigate a crime in which very clear fingerprints in soot were left at a crime scene. This was the first time a crime was solved based on fingerprint evidence. Faulds wrote a letter on the subject to the journal Nature, and more importantly, wrote a letter to Charles Darwin outlining his discoveries. Darwin at this time (1880) felt that he was too old to get involved, but passed the letter on to his cousin, the brilliant anthropologist Sir Francis Galton. Sir Francis Galton's contribution was to firmly establish that fingerprints are unique, using a simple yet elegant mathematical argument. With the permanence of fingerprints already established by Herschel, the only problem remaining before fingerprints could be use for criminal identification was the design of an efficient method of indexing the prints. The Czech physiologist and anatomist, Johannes Purkinje first recognized the fact that all fingerprints can be grouped into a small number of classes. In his doctoral thesis he identified nine different patterns, including the Arch, the Tented Arch, the Loop and six different types of Whorls. Modern fingerprint experts still consider the first three to be distinct classes but usually combine all the whorls into a single class. Sir Edward Henry was one of the pioneers to find out efficient method of indexing the dermatoglyphics. Dermatoglyphics patterns have long since been used for various purposes for their permanency and unchangeability throughout life. From the time of their formation in the foetus to the final disintegration of the skin after death the patterns remain unchanged. Of course, the ridges may be worn out and thus become invisible owing to various reasons. Though ever since the beginning of the Christian era finger patterns has been used for personal identification, yet systematic scientific studies started from the end of the nineteenth century. Uses of dermatoglyphic traits are manifold, but the anthropologists are more concerned in establishing variations in respect of traits among different human populations. However, the anthropologists are interested also in the study of dermatoglyphics in the context of twin diagnosis, paternity diagnosis, primatology, etc. Dermatoglyphics fulfill many of the conditions laid by Boyd for a good racial criterion. Dermatoglyphics traits are not modified by environmental factors. Dermatoglyphics traits are not adaptive. These are not subjected to a high rate of mutation. Genetic process of Dermatoglyphic traits is complex and is not perfectly known.

4 Ridges and patterns of the finger, palm, toes and soles are studied from different angles applying various methods. Here we shall deal with some aspects of finger patters. FINGER PATTERNS: Sir Edward Henry solved the fingerprint-indexing problem with an ingenious solution in 1897.Scotland Yard adopted the Henry-System in Since then, the system has been adopted by virtually every country in the world (with minor regional variations). Henry has classified the various finger patterns into four main types: Arches, Loops, True, Whorls and Composites. The composites form a heterogeneous assemblage of patterns. Again, three types have been identified by Galton. His three types are: Arches, Loops, and Whorls. A loop may be open to the ulnar side or to the radial side and accordingly it is termed as ulnar or radial loop. The classic and widely used notation is A= arches; Lr = radial loops; Lu= ulnar loops; and W= whorls. Another Englishman living in India, Sir William Herschel, had already solved the authentication problem by using fingerprints (again, the motivation was fraud prevention). But it was the Henry Classification system which solved the identification problem.

5 Dermatoglyphic landmark: The three basic dermatoglyphics landmarks found on the fingertip patterns are the triradii, cores and radiant. Triradii: A triraduis is formed by the confluence of three ridge systems. Core: It is the approximate center of the pattern. It is useful for ridge counting. Radiants (Type lines): Radiants are that emanate from triradius and they enclose the pattern The whorls possess two triradii, while only one triradius is present in loops. On the other hand triradius is absent in arches. Thus, generally speaking, the patterns may be identified from the occurrence of triradius. The classification dermatoglyphics specially the fingerprints, according to Henry s system is based on the availability of triradius. Apart from classification of each finger pattern types as qualitative variables, different indices are also taken into account for quantitative assessment for any individual or population. Usually three indicates are calculated on the basis of the frequency distribution of the different finger patterns. These are as follow: Furuhata s Index=Whorls x 100/loops Dankmeijer s Index=Arches x 100/Whorls Pattern Intensity Index=2 x Whorls + Loops/n Pattern intensity index: 2 x W + L / n (Number of subject / No. of fingers). Therefore Pattern intensity index (PII) represent how many triradii are there in that population. Arch is not taken into consideration in case of PII because arch does not possess any triradius. Therefore increased value of PII envisaged higher prevalence whorl while contrary to that decrease of PII indicates lower prevalence of whorl however if PII tends towards very minimum value then the prevalence of arch is higher than the other types. Dermatoglyphics can be taken as a tool for population variation.

6 Finger patterns exhibit racial / ethnic variation as shown in the table below: Population Whorls % Loops % Arches % Mongoloid 40 to to60 1 to2 Caucasoid 20 to to 70 4 to 7 Negroid to 60 6 to 7 It is evident from table that whorls are most frequent among the Mongoloid population and least among the Caucasoid population. On the other hand, loops appear most frequently among the Caucasoid groups, while among the Mongoloid and Negroid groups loops are found in equal frequencies. Again arches appear in very small number in the Mongoloid. It is most frequent in the Negroid. The position of the Caucasoid is intermediate. PALMAR DERMATOGLYPHICS In order to carry out Dermatoglyphics analyses that can be compared in different individuals, the palm has been divided into several anatomical defined areas. The areas approximate the sites of embryonic volar pads and include the thenar area, four interdigital areas and the hypothenar area.

7 Hy = Hypothenar Th = Thenar The digital and axial triradii and the main line traced from each constitute important landmarks for dermatoglyphics analysis. Typically, there are four digital triradii in the distal potion of the palm. They are found in the metacarpal region at the base of the digits II, III, IV & V. Each triradius is normally associated with one digit. By convention, they are termed a, b, c & d proceeding in radioulnar direction. MAIN LINE FORMULA: The radiants of the digital triradius traced is along its whole course within the palmer area, it constitute palmer main line, one of the dermatoglyphics characteristics usually noted in dermatoglyphics analysis. There are four main lines, each emanating from one of the digital triradii and labeled by capital letter A, B, C & D corresponding to the triradii having the same lower case letter. The termination of the main lines, recorded in the order D, C, B, A are used to express the main line formula. Periods are used to separate the numerical symbols. The main-line formula serves as an indication of the general direction of palmar ridge flow. For achieving the main line formula the palm is designated as follows:

8 The digital triradius are designated as A, B, C & D and line Main Line Index Main line formula as mentioned earlier serves as an indication of the general direction of palmer ridge flow. Cummins (1936) observed that the termini of two main lines A and D alone can adequetly reflect the ridge direction. From this observation proposal of mail Line Index based on the sum of the two numbers corresponding to the exits of main line A and D. If the resulting value is low then it indicates vertical alignment, whereas, high value reflects a tendency for the palmer ridge direction to be horizontal. CONCLUSION:

9 The skin on the fingertips and palmar and plantar surfaces of man is not smooth. It is grooved by curious ridges, which forms a variety of configurations. The scientific study of epidermal ridges and invaluable suggestion regarding recording and analysis of epidermal ridge configurations demonstrated its enormous value for population classification and importantly it s utility for personal identification.