Peter Macklem has written a very interesting short article that many readers of this blog might enjoy
Here are a few excerpts with some follow-up questions to think about.
Life’s order is characterized by emergent phenomena. These I define as the spontaneous development of self-organized order among ensembles that can neither be predicted nor explained by examining component parts in isolation. Spontaneity and self-organization mean that no external agent is sculpting the organism: it sculpts itself. Ensembles mean that an emergent system is composed of many parts. And for the component parts to self-organize, they must intercommunicate, interact, and cooperate. Life provides many interconnections: hormones, nerves, gap junctions, cytokines, and so forth. Thus understanding emergence requires studying the behavior of integrated networks. Reductionism cannot solve the secrets of emergence.
Crystals lie frozen and inadaptable deep within the ordered regimen. Deterministic chaos is found at the other extreme, characterized by weather-like instability and evanescence. Between crystals and weather a sudden phase transition occurs over a small range of energy consumption. It is here that conditions necessary for life are found. We the living exist in a complex regimen in the phase transition between order and chaos. We are there because that is the only place we can be both ordered but adaptable, stable but able to evolve. Crystals are stable and ordered but cannot adapt or evolve. Weather evolves but is unstable and cannot survive. Darwinian selection allows both survival and evolution only in the phase transition. Survival requires adaptations, but it also requires that in adapting we must preserve our order by a mechanism we call homeostasis.
Life and emergence obey the laws of physics and chemistry. But life has a third secret not mentioned by Schrodinger. The design of living organisms is not determined by physico-chemical laws. As Polanyi says, in a painting the physical and chemical properties of the paint determine what remains on the canvas, but the meaning of the painting is determined by the artist. Who is our artist? We sculpt ourselves; but our survival depends on Darwinian selection. Appropriate designs survive, inappropriate ones become extinct. Life is more than the properties of our paint. Understanding life requires knowledge of how the design of living creatures and emergent phenomena, appearing spontaneously in self-ordered, reproducing, interacting, energy-consuming, non-linear, dynamic ensembles makes us what we are. I believe this will be the next biological revolution.
Here are couple of questions that come to mind.
1. If you look at figure 1, where on that continuum would we put machines?
2. To what extent does the survival and evolution in the phase transition depend on life’s machines?
3. Just how much adaptation can occur within that phase transition without the remarkable design material we know of as proteins?