The Systems View of Life: A Unifying Vision

by Fritjof Capra

However, it is the entire organism that determines which proteins should be built and when; it is the downward causation that is the primary source of biological functions and behavior.

self-organization and emergence acquire their full potential in dynamical systems – that is, systems that change over time.

The key characteristic of such dynamical systems is that they generally operate far from equilibrium, and yet are capable of producing stable, self-organizing structures.

In classical thermodynamics, the dissipation of energy in heat transfer, friction, etc., is always associated with waste. Prigogine's concept of a dissipative structure introduced a radical change in this view by showing that in open systems dissipation becomes a source of order.

According to Prigogine's theory, dissipative structures not only maintain themselves in a stable state far from equilibrium but may also even evolve. When the flow of energy and matter through them increases, they may go through new instabilities and transform themselves into new emergent structures of increased complexity.

Thus, amplifying “runaway” feedback, which had always been regarded as destructive in cybernetics (see Section 5.3.2), appears as a source of new order and complexity in the theory of dissipative structures.

Self-balancing (negative) feedback loops maintain the system in a stable but continually fluctuating state, whereas self-amplifying (positive) feedback loops may lead to new emergent structures.

In Prigogine's theory, the second law of thermodynamics (the law of ever-increasing entropy, or disorder) is still valid, but the relationship between entropy and disorder is seen in a new light.

At bifurcation points, states of greater order may emerge spontaneously without contradicting the second law of thermodynamics. The total entropy of the system keeps increasing, but this increase in entropy is not a uniform increase in disorder. In the living world, order and disorder are always created simultaneously.

According to Prigogine, dissipative structures are islands of order in a sea of disorder, maintaining and even increasing their order at the expense ...

order “floats in disorder,”

the spontaneous emergence of order at critical points of instability is one of the most important concepts of the new understanding of life.

Observations have now shown that microbial networks of nanowires exist in a variety of environments. In the soil, they may extend underground for hundreds of meters. Some of these networks are extraordinarily dense and look strikingly like neural networks.

Lovelock recognized the Earth's atmosphere as an open system, far from equilibrium, characterized by a constant flow of energy and matter – the telltale sign of life identified by Prigogine around the same time.

What if the Earth were able to regulate its temperature, he asked, as well as other planetary conditions – the composition of its atmosphere, the salinity of its oceans, and so on – just as living organisms are able to self-regulate and keep their body temperature and other variables constant?

Rather than seeing the Earth as a dead planet, composed of inanimate rocks, oceans, and atmosphere, he proposed to consider it as a complex system, “comprising all of life and all of its environment tightly coupled so as to form a self-regulating entity”

three different levels of organization we have to consider in the complex systems of life.

The first is self-organization, the capability of assuming an organized structure thanks to the inner rules of the system.

The second level is autopoiesis, when the self-organization is such that it can regenerate from w...

Finally, there is the level of the living organism, when autopoiesis becomes associated with cognition, and we have therefore both the necess...

Thus Daisyworld, without any foresight or planning, regulates its own temperature over a vast time range by the dance of the daisies.

two forms are chiral; they are not superimposable on each other.

It seems, then, that nature is intrinsically asymmetric, and the question is: why? What is the evolutionary advantage of this asymmetry?

complexity theory (see Chapter 6), which is essentially a mathematics of patterns,

The key question asked by physicists is how a material universe exhibiting perfect symmetries – its laws being the same everywhere in space and time – can give rise to a great variety of structures and behaviors; for example, different particles governed by different fundamental forces. The answer turns out to be another general principle known as symmetry breaking.

The basic idea is the same: a symmetric situation is disturbed, becomes unstable, and consequently gives rise to striking and often complex patterns.

An “emergentist” approach to understanding the essence of the rose would be to consider its ontogeny (development),

The notion that one arrives at in the end is that the rose is an ensemble of various emergent properties – the colors, the perfume, the symmetry – without any central localization where the essence of the rose would be condensed.

These two apparently contradictory aspects of life – constancy of form and the existence of so many different forms – make up life on Earth.

In short, cellular dynamics may lead to the emergence of many proteins from a single gene and of many functions from a single protein – a far cry indeed from the linear causal chain of the central dogma.

Epigenetics is the study of heritable changes in phenotype, or gene expresssion, caused by mechanisms other than changes in the underlying DNA sequence;

In other words, the structure of the genome is the same in all these cells, but the patterns of gene expression are different. As Keller (2000) puts it, “Genes do not simply act: they must be activated.”

definition of epigenetics as “the study of heritable changes in gene function that cannot be explained by changes in DNA sequence”

One question often asked here is this: “How do these different parts ‘know’ that they belong to the same unit?” In a literal sense, this is a fallacious question, as the parts cannot “know,” but it is an interesting question from the heuristic point of view, as it obliges one to think in terms of systems biology, as well as in terms of cooperation in evolution, since these parts clearly have “learned” to positively interact with each other due to natural selection and adaptive pressure.

Her idea is, for example, that the eukaryotic cell came about through the fusion of a prokaryote with another microorganism in a kind of physical cooperation initially, which eventually gave rise to a new form of life (as an emergent property) that could self-reproduce more efficiently.

Any intelligence the system has, is at the level of the organism, not at the level of genes. Also to say that this intelligence is encoded in the program of the genes, is not correct, because…there is no such thing as a program. We are the system that allows the code to be read.

This is a very important, critical point: it is not the function that determines the structure but, rather, the opposite, the structure that determines the function.

Aristotle, in his classic text De partibus animalium (“On the Parts of Animals”), taught that “nature adapts the organ to the function, and not the function to the organ”; and Lucretius wrote in his celebrated epic poem De rerum natura (“On the Nature of Things”) that “nothing in the body is made in order that we may use it. What happens to exist is the cause of its use.”

Lucretius’ last sentence – “What happens to exist is the cause of its use” – could have been said in our time by Stephen Jay Gould or any modern evolutionary biologist.

contingency to be the main driving force of evolution

Moreover, the mutation must produce a minimal perturbation so as to respect the main function of the living cell, which is self-maintenance.

This is where the concept of contingency becomes relevant – a constellation of deterministic factors giving rise to events that are unpredictable and yet can be fully explained after they have occurred

Evolutionary changes are triggered by randomness and contingency, but the integration of the emergent genetic structures into their environment is far from random; it is a complex and highly ordered process.

not a random sequence of events but is guided by some emerging coherence,

In the language of complexity theory, this would mean that the closure of the vesicles in situ produces a bifurcation point at which an attractor, representing the entrapment of all 90 components, can emerge

“Reason, even in its most abstract form, makes use of, rather than transcends, our animal nature…Reason is thus not an essence that separates us from other animals; rather, it places us on a continuum with them.”

In other words, violence is not a general human characteristic, but rather a specifically male human characteristic.

Bateson (1972) listed a set of criteria that systems have to satisfy for mind to occur. Any system that satisfies those criteria will be able to develop the processes we associate with mind – learning, memory, decision-making, and so on.

In Bateson's view, these mental processes are a necessary and inevitable consequence of a certain complexity that begins long before organisms develop brains and higher nervous systems. He also emphasized that mind is manifest not only in individual organisms but also in social systems and ecosystems.

The central insight of the Santiago theory is the same as Bateson's – the identification of cognition, the process of knowing, with the process of life.