Nature does so many things better than we do that it isn't fair to compare our efforts to her full range of achievements. Hubristic chauvinists that we are, however, it's fun to make up a scorecard on select items in the human v. nature smackdown. To play we will have to assume (as most of us have for the last 250 years) that we are not a part of nature, but a separate force. Let's take buildings as our first challenge.
You would think that we had the ol' Lady beat on this one. Nothing in the biological world comes close to the height of our tall towers (the just-completed
Burj Dubai at 2,684 feet) or spans lengths as long as our bridges (
Akashi-Kaikyo at 6,529 feet), or creates the kind of energy and work that we do in our cities (Tokyo, Japan, at greatest adjusted per capita wealth).
Indeed, in many places we have eliminated most forms of visible non-human life in order to build these things. The tallest living thing that nature can produce? A mere 435 foot high stick called a tree (Eucalyptus regnans, named the
“Ferguson Tree,” cut down in Australia in 1872).
Every competition needs rules for judging, however, and deciding the rules reveals the differences between the two approaches. Rules, of course, mirror what's important. If we think we might want to mimic nature in order to improve ourselves and our built environment, then perhaps we should think about what's important in the biological world.
First off, bigger is not better, but often, more is. Mahon Hoagland in
“Exploring the Way Life Works” has called this optimization rather than maximization. This concept can be seen in a typical animal cell: Most of them have a 1-10 thousand nanometer diameter. Apparently, this is the most efficient size for the direct interchange of nutrients and waste through the cell membrane, striking a balance between the volume of the cytoplasm and the surface area of the membrane. And, of course, there a lot of these tiny components that make up the complicated machinery of our bodies. Bottom-up, component-linked construction is ubiquitous in the living world.
Optimization often means adaptability, which in turn often depends on generalization, the “one size fits all” concept, or, more often in nature, one material fits all. The more than 70,000 types of proteins busy at work in your body all were constructed from only 20 amino acids. Twenty! So, if it isn't material that distinguishes different proteins from one another, what is it? It's shape.
At this molecular level, shape is information, and therefore determines function. Proteins are formed from chains and folded into complex shapes with special receptor sites for specific catalysts, also proteins. Work by the proteins can only be possible, however, if there is a chemical or mechanical interaction. An interaction, in turn, implies a stimulus and a response. To sustain a stimulus/response interaction and to make it work for you, you must have some sort of control, a feedback loop. This is the “smart” in smart technology that nature has been practicing for billions of years.
Nature is very good at feedback loops: Making constant corrections to metabolism in response to stimuli in order to achieve a preprogrammed state. Biologists know it as homeostasis and builders have much to learn from it.
Our buildings are becoming smarter all the time thanks to advances in the three basic elements of the feedback loop: Programming, sensors and correction mechanisms. Low-cost wireless sensors that can be placed anywhere, sophisticated software and massively increased computational capacity have all led to this revolution in building technology.
Greater control of these building systems is also forcing a more precise balancing of them, and that will mean optimization rather than maximization will be the continuing trend in building design. Perhaps eventually we will progress beyond “smart” buildings to homeostatic ones.
Because living things can (and must) react and adjust to their environment constantly, nature employs a very different method for building than we do. A tree builds to shape. It doesn't harvest stock, cut out the parts it doesn't want and then use connectors to join disparate parts together. The tree grows its roots around the rock; its leaves bend toward the light. It also puts more cells where they are needed to relieve stress, as seen in so-called buttress roots in the trunks of tropical trees. This is just-in-time information; just-in-time material, all powered by the sun. It is this elegant economy of material and energy, made possible by little-known biological information mechanisms, that has excited scientists and engineers.
Nature has its limits, however, and so do the natural building strategies she employs. One not to be forgotten is simply the confines of three-dimensional space; there are only so many ways that you can arrange materials in space as we perceive it (see: Peter S. Stevens,
“Patterns in Nature,” or Peter Pearce,
“Structure in Nature is a Strategy for Design”). The laws of physics also come into play in determining form; nature must obey them, and as D'Arcy Thompson and Philip Ball have so adroitly explained, often nature's forms are a direct result not of evolution, but simply physical forces.
Finally, nature's solutions are limited by the DNA-prescribed tools still at hand. Steven Vogel points out in his excellent book,
“Cats Paws and Catapults,” that nature doesn't use metals or the wheel very often. Her solutions to constructing moving parts (sliding rather than rolling) are bound by her tools and quite different than ours. He reminds us also that her design brief is quite different. Nature builds to strength, while we tend to build to stiffness. Her bendy bridge design might not be so comfortable for human users.
Despite these limits, and very different objectives, nature has been able to rack up some engineering achievements that even the most anthropocentric of us would be impressed with: Bacteria that can withstand thousands of times the radiation that we can (Deinococcus radiodurans), a single organism that is 3.5 miles long (the fungus Armillaria ostoyae), animals that can essentially die and come back to life again (tardigrades), and a material, that if manufactured to scale, would be able to catch and hold a speeding jet (spider web). We should continue to study her work.
Tom McKeag teaches bio-inspired design to undergraduate design students at the California College of the Arts and to graduate architectural, science and engineering students at the University of California, Berkeley. He is the founder and president of BioDreamMachine, a nonprofit educational institute that brings bio-inspired design and science education to K12 schools. In 2006, McKeag helped establish the nation's first public elementary school course in biomimicry at the Dixie Elementary School in Marin County, Calif. In his spare time he works as a licensed landscape architect and community planner.
Tree roots - CC license by SFB579; tree on building - CC license by rogerbarker2
