Hierarchical complexity in ecological systems [Tim Allen, ISSS 1998 Paper Session, July 21/98]

These notes are a rough transcription, prepared as each individual presenter and/or commentator spoke at the ISSS 1998 conference. Gaps and errors have likely occurred. For more accurate citations, please consult the original presenters. These notes have been contributed to the ISSS by David Ing, of the IBM Advanced Business Institute (sabi@systemicbusiness.org).

Tim Allen, Botany Department, University of Wisconsin

Start with same chart this morning, but will go a different direction

In biology, those with genetics had science by the throat.

Evolution generates complexity by adding little extra pieces, to solve the next problem, and the next...

• Diagram: flat hierarchy.
• This leaves structure behind, which becomes an elaboration of structure.
• This happens with government as well.
• e.g. time-and-motion people who looked at 5 people, one standing doing nothing: holding the horse that hasn't been there 30 years.
• Patterns:
• modification by dissent: whales have a single lower jaw bone like us, because they're mammals
• convergent revolution: response to environment
• Can observe by intermediates.
• Horse's foot: running on 5 fingers, then two, then one plus a vestige, then one toe.
• Depends on who dies: leaving behind a complete track of the system evolution.

• Diagram: deep hierarchy.
• Energy dissipative system far from equilibrium systems.
• Self-simplification.
• Vertical differentiation.
• Behaviour becomes simple, but energy cost is high.
• As the energy gradient gets low enough, the bottom members of the hierarchy don't assert their identity.
• Biodiversity may be a red herring: There may be multiple hierarchies which people ignore.

• (physical) e.g. running air past a wire gives laminar flow
• Increasing wind speed gives emergent structure.
• Could instead not describe one curve as laminar flow, as there are more patterns, which are complex to be described with laminar flow.
• Even spacing: competition:
• Counter-rotational:
• e.g. emergence in origins of agriculture.
• Could describe slaughter houses as a hunting and gathering, but should probably use a different model.

• They fit in the environment the best. Revolution by natural selection

• If not enough energy for emergence, then no evolution

• March gets single flow in the water, warm top to cool bottom.
• July hot, with high gradient in temperature, results in two levels of water flow: Epiliminion and hyperlimion

New way to look at biology: what is the gradient with which we're concerned?

• Warm earth, cold space: then life emerges.
• Botany disappears into transpiration -- just wicks.
• The important energy does nothing with burning carbon, but with transpiration of water.
• Burning a tree to determine energy: how long would a tree have to breath to have the same energy? A month?
• The energy in the carbon is trivial.
• 100 calories to boil water, 5-1/2 times more to make it steam.
• Evolution: making a wick
• Genetics: how to make a wick.

• Heat goes into tropics, and therefore tropical rainforests.
• Clouds at 35000, is coolest in the tropics: the trees put them there!
• Surface temperature of vegetation:
• Hay field undisturbed can cool by 3 degrees.
• Mowing it increases cooling capacity.
• Soybean field vs. temperature: increased nitrogen increases cooling capacity, until the instructions don't tell you how to add any more nitrogen.

• Look at parts: inspectorate, which gives evolution.
• Generative: which looks at thermodynamics.

• Structure versus dynamics.

• Biologists are too focused on one model.
• When you know what happens, can look at branches in the evolution.
• Then, both generative and inspectorate
• prospect and generative: gradients
• retrospect and generative: accident
• prospect and inspectorate: physical limits
• retrospect and inspectorate: adaptation

• Complicatedness vs. complexity fight each other, to produce system behaviour.