Variations between the parts of a system.

We can think of diversity as coming in two important forms:

First, there is strong diversity (or ‘structural diversity’). This is the diversity of the parts which carry out specialist roles within a complex system, such as the radically different—but strongly-connected—organs within the body of an animal.

Secondly, there is the weak diversity (or ‘textural diversity’) within a modular system. Its parts are similar to each other and only loosely interdependent, but the small variations may still be necessary for it to function.

Examples of weak diversity in a modular system include:

• Variation between individual members of a herd of antelopes.

• The acutely-discriminating personalities of politics in a primate group, supporting its complex role in sustaining cohesion and conserving genetic inheritance.D42

• The different ways in which resilient communities adapt to local conditions.

• The limited range of diversity in a communications system. Language is only intelligible because its grammar and vocabulary keep it within boundaries. For example, where clothes have something to say about people, the nuance and meaning they convey depends on an agreed convention: the clothing worn by the Roman negotiators at the city of Tarentum in the third century BC was grossly strange from the Greeks’ point of view; it was too different to be intelligible. For the Greeks, those billowing togas had nothing to say—gesture without meaning—and had them falling about with laughter. The negotiators took a huff and went home. Then there was war (Needs and Wants).D43

• And maybe the most familiar example is the difference between varieties within a species—sheep, for instance. Some (Romney Marsh) are good at coping with wet conditions, some (North Ronaldsay) thrive on seaweed; some (Border Cheviots) are hardy in bitter winters or (Comisana) scorching summers; some (Black Welsh) are natural mountaineers; some (Spæl) grow long smooth wool, some (Roquefort) produce milk for blue cheese. Diversity could be reduced, and a hybrid vigour could perhaps be achieved, if all these breeds were blended into one Standard Eurosheep. But that gives us the Sheep Without Qualities, its character smoothed away, its hopes of resilience over. We would have sheep that had adapted to nothing in particular. Perhaps Hyde Park would suit them.

Or it may take the form of diversity in timing:D44

• Budworms that attack spruce fir forests only become a plague when the forest is mature (when foliage is so thick that the birds cannot get at them). The forest cannot prevent budworm attack but, left to themselves, local areas die off at different times and recover, and the forest as a whole carries on (Sacrifice-and-Succession). If you try to stop the budworm by routine spraying, then local life-cycles become synchronised, the whole forest dies back at once, and recovery is harder.D45

• Differences in timing are core to the ways in which hunter-gatherers share hunting grounds (Script). These arrangements reduce their risk by forcing all parties to hunt over a wider, more diverse, range than they would if they did not share territories.D46

• Complementary diversity in timing is critical to the process of succession as a recovery-resilient system finds its way back from trauma. In the “From Sand to Forest” sidebar we see an ecology—ultimately a woodland—owing its existence to the pioneering work of lyme grass many years previously.

• And there is the impressive case of the brief, ecstatic quickening of the desert toad, whose whole life-cycle is squeezed into the rare occasions when it rains, and who—in order to minimise the time from conception to conception, and to put on weight in the short time available—eats its little brothers and sisters.D47


Getting the timing right

It takes an exceptionally hardy plant to be among the first to colonise a sand dune: salt, flood, drought, almost no nutrients in the soil, and no surrounding plants to protect it or to cooperate. Lyme grass has made a speciality of surviving these conditions. It tolerates salt; its leaves have a waxy coating to conserve water; it binds the sand and traps it as it blows.

But in due course the sand smothers it, and marram grass takes over. It, too, gets buried by the sand, but it can grow through it, and its roots bind the sand at a deep level, providing stability for more plants such as sand sedge, sea holly, sea bindweed, sea spurge and Portland spurge. The spurges contain a white latex which makes them taste unpleasant to rabbits.

Then come plants seeded by the wind, such as dandelions, groundsels, thistles, hawkbits, hawkweeds, hawk-beards and ragworts which, along with grass, grazed by the rabbits, form a short, tight turf, fertilised by the rabbit droppings. Next come lichens and mosses, followed by wild thyme, then grasshoppers, caterpillars, bees, and spiders and their predators, including mice, voles, skylarks and kestrels.

Now there is enough soil for bushes, such as hawthorn, elder and brambles, followed by creeping willow and orchids. Eventually, trees will dominate, and (unless something happens to break the succession) the area will mature into woodland.D48

The weak diversity within modular systems, then, supplies a robust ecology with the prospects of stability, evolution and resilience. Meanwhile, strong diversity provides sharply different, but complementary, forms (e.g. organs, limbs) which join up to undertake different roles in support of the complex systems (e.g., sheep) of which they are part.

And within a natural ecosystem, reciprocal exchange between species—providing and receiving nutrients, or supporting predators that keep your pests in check—is only made possible by diversity. Difference is necessary for reciprocity; without it, there is nothing to exchange.D49

Reports of a decline in diversity are therefore not merely matters of sentimental regret: they tell us something about the system’s health and expectation of life. Here is a description of diversity in decline in the case of the human ecology—John Stuart Mill’s lament for its passing in the United Kingdom of the 1850s—inviting reflection on why that matters. Diversity, he writes, is . . .

. . . every day diminishing. Formerly, different ranks, different neighbourhoods, different trades and professions, lived in what might be called different worlds; at present to a great degree in the same. Comparatively speaking, they now read the same things, listen to the same things, see the same things, go to the same places, have their hopes and fears directed to the same objects, have the same rights and liberties, and the same means of asserting them. And the assimilation is still proceeding. The increase of commerce and manufacture promotes it. A more powerful agency than even all these, in bringing about a general similarity among mankind, is the complete establishment, in this and other free societies, of the ascendancy of public opinion in the State [so that] there ceases to be any social support for nonconformity. The demand that all other people shall resemble ourselves grows by what it feeds on. If resistance waits till life is reduced nearly to one uniform type, all deviations from that type will come to be considered impious, immoral, even monstrous and contrary to nature.D50

If the increase of commerce and manufacture promotes uniformity, their coming decrease will demote it. Localities will develop approaches adapted to their particular circumstances and places, going their separate ways, some of which may (as Mill puts it) “be considered impious, immoral, even monstrous and contrary to nature”. Kirkpatrick Sale agrees: local communities of the future will . . .

. . . create their own political systems according to their own environmental settings and their own ecological needs, and there is no reason to think they would necessarily be compatible—or even, from someone else’s point of view, good.D51

Given a chance, local economies work out their own solutions. The surge in creativity and small-scale enterprise following the disaster of the collapse in grain prices in the last two decades of the nineteenth century is one example of small farmers and horticulturalists, under pressure, using their nous in diverse ways. The agricultural historian Joan Thirsk writes,

Innovative activities under a regime of alternative agriculture were branching out in a multitude of different directions, but most were modest, local efforts, which only the assiduous seeker in out-of-the-way places was likely to uncover. The statisticians were the very last to become aware of them and give them regular attention.D52

And she summarises,

The economic strategies of small-holders were bewilderingly diverse: they might well exasperate politicians seeking truths that could be expressed in a few crisp generalities.D53

There are hard times ahead for regulatory agencies and for generalities. The lean economies that succeed will do so because they have made use of local diversity, the distinctive challenges and troubles, the airs and graces, of particular places and times, working in very diverse ways towards the common aim of life after oil.


Related entries:

Resilience > Resilient Systems > Diversity, Capital, Lean Food.

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David Fleming
Dr David Fleming (2 January 1940 – 29 November 2010) was an economist, historian and writer, based in London. He was among the first to reveal the possibility of peak oil's approach and invented the influential TEQs scheme, designed to address this and climate change. He was also a significant figure in the development of the UK Green Party, the Transition Towns movement and the New Economics Foundation, as well as a Chairman of the Soil Association. His wide-ranging independent analysis culminated in two critically acclaimed books, Lean Logic and Surviving the Future. A film about his perspective and legacy - The Sequel: What Will Follow Our Troubled Civilisation? - was released in 2019, directed by BAFTA-winning director Peter Armstrong. For more information, including on Lean Logic, click the little globe below!

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