Scientific American: Feature Article: The Bottleneck: February 2002 The consequences of their reproductive prowess are multiple and deep. The people of the developing countries are already far younger than those in the industrial countries and destined to become more so. The streets of Lagos, Manaus, Karachi, and other cities in the developing world are a sea of children. To an observer fresh from Europe or North America, the crowds give the feel of a gigantic school just let out. In at least 68 of the countries, more than 40 percent of the population is under 15 years of age--e.o. wilson on population dynamics. (Italy has the lowest per cap birth rate???)