An interesting parallel

A grove of Aspens appears to the uninitiated as a grove of individual trees. Biologists these days tend to regard them as a single organism since they are clones grown from a single seedling. A root system proliferates underground, and may live for thousands of years, sending up new trees from time to time. The individual trees live for a century or more, but the entire organism is very long lived.

We think of Manhattan, one of the places in which the skyscraper was invented, in terms of its above ground buildings and indeed its skyline. However, there is an underground support network of subways, aqueducts, sewerage, steam lines, fiber optics, gas lines, not to mention outmoded systems such as the pneumatic tubes that once carried messages from building to building. The network is dense, and parts of it are more than 100 feet deep. Individual building are replaced but the overall structure of the city remains.

I could try to extend the analogy to discuss the social and economic environment which determines the growth and survival of the city, but I will refrain from doing so!