Background The human external ear is unique in every individual in terms of shape, size and dimension making it suitable in forensic anthropology for sex estimation and personal identification purposes. The study aimed to evaluate sexual dimorphism and ethnic specificity of the external ear in major Nigerian ethnic populations. Results There was variation in the morphological features of the external ear of the sampled subjects. The external ear features vary in the right and left ears in both sexes of the ethnic groups. All variables were statistically significant (p < 0.05) except ear width. Univariate discriminant function gave sex prediction accuracies between 56.4 and 57.3% for left and right ears, respectively. Population-specific sex prediction accuracy using stepwise discriminant analysis of left ear variables ranged 58–69.7% and 57.5–74.2% for right ear. Conclusion The ear parameters showed potential for sex estimation, but cannot be solely relied upon for personal identification.

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Background Colour vision deficiency (CVD), also referred to as colour blindness, is the failure or decreased ability to distinguish between certain colours under normal lighting conditions. It is an X-linked genetic disorder with varying degrees of prevalence in different populations. There is presently no report on the prevalence of CVD among students of the selected tertiary institution. Hence, the present study was aimed at determining the occurrence and genetics of CVD among students from designated tertiary institutions in Lagos state. A cross-sectional survey was employed in recruiting 1191 study subjects from three tertiary institutions in Lagos, Nigeria. Results The overall occurrence of CVD among the study participants was 2.85%. There were 24 (4.29%) males and 10 (1.58%) females affected. Among the colour vision deficient individuals, 18 (1.51%) and 16 (1.34%) were deuteranomalous and protanomalous, respectively. Also, the prevalence of CVD varies across ethnic groups of the studied subjects with the highest occurrences (3.57%) observed in the Yoruba ethnic subpopulation and the least (1.45%) among the Hausas. Conclusions More males than females were found to be colour vision deficient, and there were more deutans than protans. Early screening for CVD should be encouraged among school children to guide the choice of future profession and help mitigate work hazards resulting from being colour deficient.

The mucosa contains soluble antigens of the ABO blood group system. Secretor status as a trait has been linked to a variety of clinical diseases and is determined by the individual’s fucosyltransferase 2 (FUT2) allele. The distribution of secretor status in relation to ABO blood group phenotypes varies from region to region, with medicolegal significance. There is a dearth of information on the secretor status of the studied population. The aim of the present study was to evaluate the secretor status of the ABH in a Nigerian population. To achieve this, fresh saliva samples (~5 ml) were collected from 325 (181 males and 144 females) apparently healthy individuals in the urban city of Lagos. Secretor status was determined by haemagglutination inhibition test with the saliva samples of participants. Results showed that 85% of the participants were secretors and 15% were non-secretors with no statistically significant differences (p>0.05) between male and female gender. The frequencies of the Secretor, Se and Non-secretor, se genes were 0.543 and 0.457, respectively while the frequencies of the SeSe, Sese, and sese genotypes were 0.294, 0.496, and 0.209, respectively. The participants’ ABO blood group distributions were 65.5% group O, 16.6% group A, 15.1% group B, and 2.8% group AB. The incidence of secretors across blood group was 89% in group O, 85% in A, 79% in B and 67% in AB. However, there were no statistically significant variations in secretor status and ABO blood group (p>0.05). In conclusion, the study shows that there are more secretors than non-secretors, and the ability to secrete the ABH antigens are independent of ABO blood of individuals.