Human major infections: Tuberculosis, treponematoses, leprosy-A paleopathological perspective of their evolution.

The key to evolution is reproduction. Pathogens can either kill the human host or can invade the host without causing death, thus ensuring their own survival, reproduction and spread. Tuberculosis, treponematoses and leprosy are widespread chronic infectious diseases whereby the host is not immediately killed. These diseases are examples of the co-evolution of host and pathogen. They can be well studied as the paleopathological record is extensive, spanning over 200 human generations. The paleopathology of each disease has been well documented in the form of published synthetic analyses recording each known case and case frequencies in the samples they were derived from. Here the data from these synthetic analyses were re-analysed to show changes in the prevalence of each disease over time. A total of 69,379 skeletons are included in this study. There was ultimately a decline in the prevalence of each disease over time, this decline was statistically significant (Chi-squared, p<0.001). A trend may start with the increase in the disease's prevalence before the prevalence declines, in tuberculosis the decline is monotonic. Increase in skeletal changes resulting from the respective diseases appears in the initial period of host-disease contact, followed by a decline resulting from co-adaptation that is mutually beneficial for the disease (spread and maintenance of pathogen) and host (less pathological reactions to the infection). Eventually either the host may become immune or tolerant, or the pathogen tends to be commensalic rather than parasitic.

Recently increased prevalence of the human median artery of the forearm: A microevolutionary change.

The median artery has been considered as an embryonic structure, which normally regresses around the 8th week of gestation. However, various prevalences have been reported in adults since the 18th century. Furthermore, in a study by Henneberg and George (1995; Am J Phys Anthropol 96, 329-334), has suggested that increasing prevalence of the median artery during the 20th century was a 'possible secular trend'. The present study, conducted nearly a quarter of a century later, is a continuation of that study. A total of 26 median arteries were found in 78 upper limbs obtained from Australians aged 51 to 101 years, who died in the period 2015-2016, a prevalence rate of 33.3%. Analysis of the literature showed that the presence of the median artery has been significantly increasing (p = .001) over time, from approximately 10% in people born in the mid-1880s to approximately 30% by the end of the 20th century. The significance of the prevalence increased to a p value <.0001, when the results of the present study and other studies conducted by our research team were combined. After removal of the studies that were possibly biased, because of their specific focus on the evolutionary aspects of the median artery, the significance remained at p = .018. The present study provides an example of microevolutionary changes in the internal anatomy of the human body. Second-order polynomial regression of the median artery's prevalence on dates of birth shows that it is now present in 35% of people and predicts that people born 80 years from now will all carry a median artery if the trend continues. When the median artery prevalence reaches 50% or more, it should not be considered as a variant, but as a 'normal' human structure.

Use of units of measurement error in anthropometric comparisons.

ABSTRACT: Anthropometrists attempt to minimise measurement errors, however, errors cannot be eliminated entirely. Currently, measurement errors are simply reported. Measurement errors should be included into analyses of anthropometric data. This study proposes a method which incorporates measurement errors into reported values, replacing metric units with 'units of technical error of measurement (TEM)' by applying these to forensics, industrial anthropometry and biological variation. The USA armed forces anthropometric survey (ANSUR) contains 132 anthropometric dimensions of 3982 individuals. Concepts of duplication and Euclidean distance calculations were applied to the forensic-style identification of individuals in this survey. The National Size and Shape Survey of Australia contains 65 anthropometric measurements of 1265 women. This sample was used to show how a woman's body measurements expressed in TEM could be 'matched' to standard clothing sizes. Euclidean distances show that two sets of repeated anthropometric measurements of the same person cannot be matched (> 0) on measurements expressed in millimetres but can in units of TEM (= 0). Only 81 women can fit into any standard clothing size when matched using centimetres, with units of TEM, 1944 women fit. The proposed method can be applied to all fields that use anthropometry. Units of TEM are considered a more reliable unit of measurement for comparisons.

Estimating a child's age from an image using whole body proportions.

The use and distribution of child pornography is an increasing problem. Forensic anthropologists are often asked to estimate a child's age from a photograph. Previous studies have attempted to estimate the age of children from photographs using ratios of the face. Here, we propose to include body measurement ratios into age estimates. A total of 1603 boys and 1833 girls aged 5-16 years were measured over a 10-year period. They are 'Cape Coloured' children from South Africa. Their age was regressed on ratios derived from anthropometric measurements of the head as well as the body. Multiple regression equations including four ratios for each sex (head height to shoulder and hip width, knee width, leg length and trunk length) have a standard error of 1.6-1.7 years. The error is of the same order as variation of differences between biological and chronological ages of the children. Thus, the error cannot be minimised any further as it is a direct reflection of a naturally occurring phenomenon.

Comparing the face to the body, which is better for identification?

As early as the nineteenth century, measurements of the face and body were used for forensic identification. It was believed that no two individuals had the exact same measurements. However, this was overtaken by fingerprint analysis because it was considered more reliable in court proceedings as the probabilities of finding matching individuals could be calculated. With the standardisation of photographs, identification primarily occurs from the face. With the ability to take measurements from photographs, why not use the body? The Army Anthropometry Survey (ANSUR) database contains anthropometric measurements of 3982 individuals. Eight facial and eight body measurements were compared to investigate whether or not there is enough information on the body to use for identification. Measurements were compared by adding one measurement to the other(s) in a stepwise approach until there were no duplicate cases where two or more individuals share the same combination of measurements. Results consistently show that less body measurements are needed to find no duplicates when compared to the face. The larger the range of each of the measurements, the less chance there is of finding a duplicate. With the combination of eight body measurements, it is possible to achieve a probability of finding a duplicate to the order of 10(-20) or 1 in a quintillion. These results are comparable with fingerprint analysis. The body is more variable than the face and should be used in identification. An advantage to using the body is that larger dimensions are easier to locate on images and not affected by facial expression.

Are human faces unique? A metric approach to finding single individuals without duplicates in large samples.

In the forensic sciences it is inferred that human individuals are unique and thus can be reliably identified. The concept of individual uniqueness is claimed to be unprovable because another individual of same characteristics may exist if population size were infinite. It is proposed to replace "unique" with "singular" defined as a situation when only one individual in a specific population has a particular set of characteristics. The likelihood that in a population there will be no duplicate individual with exactly the same set of characteristics can be calculated from datasets of relevant characteristics. To explore singularity, the ANSUR database which contains anthropometric measurements of 3982 individuals was used. Eight facial metric traits were used to search for duplicates. With the addition of each trait, the chances of finding a duplicate were reduced until singularity was achieved. Singularity was consistently achieved at a combination of the maximum of seven traits. The larger the traits in dimension, the faster singularity was achieved. By exploring how singularity is achieved in subsamples of 200, 500, etc. it has been determined that about one trait needs to be added when the size of the target population increases by 1000 individuals. With the combination of four facial dimensions, it is possible to achieve a probability of finding a duplicate of the order of 10(-7), while, the combination of 8 traits reduces probability to the order of 10(-14), that is less than one in a trillion.

The extent to which garments affect the assessment of body shapes of males from faceless CCTV images.

Closed circuit television (CCTV) systems are being widely used in crime surveillance. The images produced are of poor quality often face details are not visible, however expert witnesses in the field of biological anthropology use morphological descriptions of body shapes in an attempt to identify persons of interest. These methods can be applied to individual images when other cues such as gait, are not present. Criminals commonly disguise their faces, but body shape characteristics can be used to distinguish a person of interest from others. Garments may distort the body shape appearance, thus this study was undertaken to investigate the effects of garments on the description of body shape from CCTV images. Twelve adult males representing a wide body shape range of Sheldonian somatotypes were photographed in identical garments comprising of tight fitting black shirt, horizontally striped shirt, padded leather jacket and in naked torso. These photographs were assessed by 51 males and females aged 18-50 years, with varying levels of education, and different experience in use of CCTV images for identification of people, to identify the 12 participants. The effect of assessors was not significant. They correctly distinguished 88.6% of individuals wearing the same wear, but could not match the same individuals wearing different wear above the random expectations. However, they matched somatotypes above random expectation. Type of clothing produced little bias in somatotype matching; ectomorphic component of individuals wearing black shirts and padded jackets was overestimated and underestimated, respectively. In conclusion, type of the wear had little effect in the description of individuals from CCTV images using the body shapes.

Effects of garments on photoanthropometry of body parts: application to stature estimation.

Person identification from images is an important task in many security applications and forensic investigations. The essence of the problem comes down to measuring key observable anatomical features which can help describing similarities or differences between two or more individuals. In this paper, we examine how different types of garments affect the placement of body markers that enable precise anatomical human description. We focus in particular on landmark positioning errors on the upper limb. Closed-form formulae are provided to compute the maximum likelihood estimate of upper limb length from an image. Subject stature is then predicted from the limb length through a regression model and used as identification criterion. Following initial laboratory experiments, the technique is demonstrated to be invariant to posture and applicable to uninformed subjects in unconstrained environments. Seven technical errors of measurement and statistical tests are quantified empirically from statures obtained by three assessors. Results show that thicker garments produce higher inaccuracies in landmark localisation but errors decrease as placement is repeated, as expected. Overall, comparison to truth reveals that on average statures are predicted with accuracy in excess of 96% for the worst assessor.

Body frame variation and adiposity in development, a mixed-longitudinal study of "Cape Coloured" children.

OBJECTIVES: The obesity epidemic is impacting both developed and undeveloped countries worldwide. It has only been recently that wide scale public campaigning has focused on prevention rather than intervention. Individual variations in food metabolism and energy expenditure may be responsible for much of the adiposity present amongst individuals. This article studies individual variation in relationship between lean trunk size and adiposity. METHODS: A mixed longitudinal growth study was conducted between 1986 and 1995 among urban and rural "Cape Coloured" schoolchildren from the Western Cape Province of South Africa. The sample consists of 127 females and 130 males between the ages of 6 and 20 years measured 6-9 times each. Correlations between age-standardized triceps, subscapular and abdominal skinfold thicknesses and quotient indices obtained by expressing trunk length, lower limb, and upper limb lengths and bi-acromial and bi-iliocristal diameters as percentages of body height were explored for each year of growth. RESULTS: Significant correlation coefficients (P < 0.05) between 0.087 and 0.511 were found in both males and females, between bi-acromial and bi-iliocristal indices and three skinfold thicknesses, but not between trunk and limb lengths and skinfolds. CONCLUSIONS: Skeletal frame width and amount of adiposity are correlated. The correlation persists longitudinally throughout childhood and adolescence in individuals living in very poor, as well as, in good environmental conditions.