The man with mutton-chop whiskers pulled strongly at the oars of his small wooden boat, thrusting his way through the thick mat of weeds that hindered his progress across the shallow Illinois lake. Even on this cold February day he was perspiring in his black frock coat as he paused occasionally to pull up a handful of plants, observing with interest that they were covered with tiny shells and alive with small crustaceans. Behind the boat trailed a dredging net, designed to catch the more mobile denizens of the lake – the “pumpkinseed”, a sunfish whose resplendent colors of orange and yellow were set off with patches of green, scarlet and purple; a range of other sunfish; two varieties of black bass; the common perch; and a host of others.
The fish were there to feed on the small creatures that lived among the weeds. The man was there because he wanted to understand the relationship between all of the lake’s inhabitants. He would later describe it as “an equilibrium of organic life,” where every species played a role. In modern terminology, he viewed the lake as an ecosystem. He was one of the first people to think about nature in this way.
The man was Stephen Forbes – a self-taught scientist who had become the official entomologist for the State of Illinois. His pioneering studies of the Northern Illinois lakes would eventually win him fame as a father of modern scientific ecology. He provided one of the first scientific explanations of what has become known as the balance of nature – the idea that natural systems have an inbuilt system of self-regulation, where the checks and balances mean that the long-term stability of the system is assured, so long as we don’t interfere with it.
The checks and balances, he thought, lay in the different reproduction rates of the various species. Prey species, he argued, must “produce regularly an excess of individuals for destruction, or else … must certainly dwindle and disappear.” A predator species, on the other hand “must not appropriate, on an average, any more than the surplus and excess of individuals upon which it preys, for if it does so, it will regularly diminish its own food supply, and thus indirectly, but surely, exterminate itself.”
The idea was appealing – so appealing that it was appropriated by economists like Adam Smith in his proposal of the “invisible hand” of competition in the free market.
There’s just one problem – the idea is wrong, at least in the long term, because there are many, many feedback mechanisms in complex societies, economies and ecosystems. Some tend to maintain stability, but others can lead to runaway change and collapse. Understanding how this happens, and what (if anything) we can do about it is one of the most important problems (perhaps the most important) facing us today.
Don’t get me wrong – this is not a critique of any particular economic or political system, or indeed any approach to the management of the world’s ecosystems. But all face the same problems. Over the next few posts I will outline how scientists have been thinking about them, and lament the way that politicians are taking so little notice.
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Adapted from Chapter 1 of Len Fisher Crashes, Crises and Calamities