Capra and Nature

In Chapter 7, Capra discusses in detail examples of dissipative structures. I really enjoyed the discussion of the plant cell, because A) I have a soft spot in my heart for photosynthesis (it's just so cool!) and B) I have a hard time looking at cells in a reductionist way, and Capra's approach is MUCH easier on my brain. Earlier in the reading I had struggled with the term "Autopoiesis," but this chapter allowed me to thoroughly wrap my brain around the term. Autopoiesis is the pattern of life. If two wheels, handle bars, spokes, gears, a seat, and peddles that are turned by your feet is the pattern of a bicycle, then the pattern of life two can be broken down. In fact, I was just tutoring a young lady about biology, and we went over the characteristics of life without calling them what they really are--the pattern of life. A living thing must be able to (1) Adapt internal conditions on a continual basis to maintain internal homeostasis (2) Use energy to power life processes (aka Metabolism) (3) Grow and develop (4) Reproduce (5) Change through time (aka EVOLVE) and (6) Respond to stimuli. Capra calls the response to stimuli the response of "mind." I found his definition of the mind very confusing at first, but the more I think about it the more I like it. Having a mind means being able to perceive, and all living things perceive, even organisms with no brain. One only needs to watch a vine climb a lattice to understand that the vine is perceiving its surroundings. The pattern of organization that is life (autopoiesis) and the continual embodiment of that pattern (structure) is what defines life according to Capra. Autopoiesis is easy to recognize. Like you recognize many types of bikes, you can recognize life in its myriad forms. I really like this definition of life! One of my favorite aspects of this definition as presented by Capra is that all living things have a mind. The implications for life perceiving the world are staggering, especially with respect to conservation (life will respond, so don't tweak nature too far!).

In Chapter 8, Capra digs deeper into dissipative structures. He helped define the nature of these structures in Chapter 7 by stating that they are structurally stable while continuous flowing. It is the flow of energy or matter in and out of the structure that makes it dissipative. He again refers to the cell as an example in Chapter 7. In Chapter 8, he uses a food cycle of an ecosystem as an example of a dissipative structure. Clearly, nature is an open system, but with structure. As Capra puts it, " The understanding of living structures as open systems provided an important new perspective, but it did not solve the puzzle of the coexistence of structure and change, order and disorder." The idea of dissipative structures helped ease the seeming conflict of interest of order and disorder.

Capra discusses bifurcation points as "thresholds of stability at which the dissipative structure may either break down or break through to of several new states of order." There are many things that affect the direction of this bifurcation point. A few of Capra's points stuck with me, particular with my mind constantly relating the ideas to an ecosystem: (1) History matters, (2) Noise matters, (3) Nature is unpredictable. I think with regards to ecosystem modeling, these points are particularly important.

And then, Chapter 9 appears and I lose my understanding of autopoiesis again. I was thinking of autopoiesis as the pattern of life, but it appears to mean more or less: life-like in pattern? Scientists have been able to "simulate" life by creating autopoietic, self-organizing networks. These modeled systems eventually returned to a state they had been to previously, and a cycle of states begins again. Capra calls these "cycles of states" attractors, and then he uses the word attractors again and again. As I often do when I don't understand Capra, I looked up "attractors" on Wikipedia. They define it as "a set towards which a dynamical system evolves over time." Capra refers to living sytems in nature, and states that many of them--including ecosystems--are really just autopoietic systems that exhibit many alternative attractors. Although these systems have a chaotic element to them, they also display order. Figure 9-4 elegantly displays the relationship between complexity and the number of attractors. Capra references the fact that the components of dynamic living systems have different levels of independent existence.

Of course as we are discussing autopoiesis, dissipative structures, autopoietic networks, it only makes sense to discuss the Gaia hypothesis. Capra goes in depth to discuss the various aspects of the Gaia system as it relates to autopoiesis: self-bounded, self-generating, and self-perpetuating. "A key characteristic of Gaia is the complex interweaving of living and nonliving systems within a single web. This results in feedback loops of vastly different scales." These feedback loops of various scales, are what fascinated me as an ecologist and evolutionary biologist.

*Phew* That was a lot of Capra to digest.