global cities

clipped from www.economist.com WHETHER you think the human story begins in a garden in Mesopotamia known as Eden, or more prosaically on the savannahs of present-day east Africa, it is clear that Homo sapiens did not start life as an urban creature. Man's habitat at the outset was dominated by the need to find food, and hunting and foraging were rural pursuits. Not until the end of the last ice age, around 11,000 years ago, did he start building anything that might be called a village, and by that time man had been around for about 120,000 years. It took another six millennia, to the days of classical antiquity, for cities of more than 100,000 people to develop. Even in 1800 only 3% of the world's population lived in cities. Sometime in the next few months, though, that proportion will pass the 50% mark, if it has not done so already. Wisely or not, Homo sapiens has become Homo urbanus.