Human Cities -Have They Evolved Beyond The Bounds of Biology?

For the first time in history, the majority of the people on our planet live in cities. Going forward, human history will become urban history: homo sapiens has evolved into homo urbanus.

The back story for this profound evolutionary shift in human behavior is that fact even in 1800 only 3% of the world's population lived in cities.

Dr. Geoffrey West, President and Distinguished Professor of the Santa Fe Institute, led a team of scientists that has found that city growth driven by wealth creation increases at a rate that is faster than exponential. The only way to avoid collapse as a population outstrips the finite resources available to it is through constant cycles of innovation, which re-engineer the initial conditions of growth. But the greater the absolute population, the smaller the relative return on each such investment, so innovation must come ever faster.

Thus, the bigger the city, the faster life is; but the rate at which life gets faster must itself accelerate to maintain the city as a growing concern so much so that to maintain growth, major innovations must now occur on time-scales that are significantly shorter than a human lifespan.

"In this crucial sense cities are completely different from biological organisms, which slow down with size; their relative metabolism, growth rates, heart rates, and even rates of innovation - their evolutionary rates - systematically - and predictably - decrease with size," West said. "Several thousand years ago the evolution of social organizations in the form of cities brought a new dynamic to the planet that seems to be uniquely human: People actually do walk on average faster in larger cities whereas heart rates decrease as animal size increases."

Economist writer-at-large, Johnny Grimond's observations underscore the findings of the Santa Fe Institute's West, writing that with the city mankind has created an organism operating beyond the bounds of biology.

In this fascinating and brilliant analysis Grimond outlines the growth and importance of cities through history:

"First, in the Fertile Crescent, the sweep of productive land that ran through Iraq, Syria, Jordan and Palestine, from which Jericho, Ur, Nineveh and Babylon would emerge. In time came other cities in other places: Harappa and Mohenjodaro in the Indus valley, Memphis and Thebes in Egypt, Yin and Shang cities in China, Mycenae in Greece, Knossos in Crete, Ugarit in Syria and, most spectacularly, Rome, the first great metropolis, which boasted, at its zenith in the third century AD, a population of more than one million people."

"It was in the city" Grimond points out, "that man was liberated from the tyranny of the soil and could develop skills, learn from other people, study, teach and develop the social arts that made country folk seem bumpkins. Homo urbanus did not just live in a town: he was urbane."

Like the species of the planet, cities mimic biodiversity, with some urban centers notable for their religious role such as latter-day Rome, or as the hub of an empire -Constantinople, or as centers of administration such as Mandarin Beijing, or political development, in Medici Florence, or learning at Bologna and Fez, or commerce at Hamburg, or a special product such as Toledo. Like species of animal life, some flourished, some died, from forces as varied as conquest, plague, misgovernment or economic collapse.

Grimond sums up noting that "the sheer scale and speed of the current urban expansion make it unlike any of the big changes that have punctuated urban history. It mostly consists of poor people migrating in unprecedented numbers, and then producing babies on a similarly unprecedented scale. It is thus largely a phenomenon of poor and middle-income countries; the rich world has put most of its urbanization behind it."

Posted by Casey Kazan.

Economist Link

Audio Interview with Johnny Grimond

Urban Life -An Organism Beyond Biology