Maternal age and Ethnicity in determining Demography and Selection Intensity parameters among North Indian Muslims

Reproductive fitness is best studied by taking together a number of parameters like the mean number of offspring produced, preadolescent mortality rate, sex ratio and the rate of selection intensity. The Muslims of Aligarh city are predominantly Sunnis, though a considerable number of Shias are also there. Among the Sunnis approximately one fourth of the population is Syed, Sheikh, Moghal and Pathan, while three fourths belong to various lower Biradaris. In the present study we have reported incidence of marriage, reproductive fitness, mortality and selection forces operative among women of high rank (Ashraf) and low rank (Ajlaf) of Muslims in the northern region. Ashraf comprises sheikh, Syed and Pathan, whereas Ajlaf have Qureshi, Saifi and Ansari biradaris. Maternal age was scored as above 45 and below 45 among each of the biradaris. Significant effects of maternal age were seen on fetility, mortality, and sterility and secondary sex ratio of the offspring, whereas populations did not show consistent difference except between Ashraf and Ajlaf taken separately.