This includes birds, reptiles, and many other animals. A type III curve is characterized by a decreasing concave line. This curve shows a higher mortality rate early in life; if the organism survives, it is more likely to live longer. This is observed in small mammals and marine invertebrates. “The general shape of the survival curve is fixed for each species, however, the convexity of the curve is very sensitive to environmental conditions and the genetic makeup of the population. This fact suggests that the general shape of the life table can provide information about the genetic variability of the population, the range of environmental factors that affect the population, or the incidence of random events in the lives of different individuals” (http ://www.nature.com/nature/journal/v275/n5677/abs/275213a0.html). Here we will look at survival between urban and rural populations before and after