Oxigênio em Delanda (2011)

With the emergence of the first living creatures the aqueous environment we have been exploring acquired a new feature: a gelatinous stratum of colonial bacteria at the interface between bottom sediments and water forming the earliest biosphere. This new stratum remained deceptively simple for over two billion years because the motionless microorganisms that composed it hardly changed in their anatomy. [Nota de rodapé 1: J. William Schopf, J.M. Hayes, and Malcolm R. Walter. Evolution of Earth’s Earliest Ecosystem. In Earth’s Earliest Biosphere. Edited by J. William Schopf. (Princenton: Princeton University Press, 1983). p. 375–81.] But contrary to what a superficial look at their external appearance may suggest those ancient organisms had managed to discover over that period of time all the biochemical processes of energy extraction that exist today. After that, evolution produced many new mechanisms to use energy to perform work, for complex locomotion or for neural control, for instance, but no new major ways of extracting energy from gradients. [Nota de rodapé 2: Franklin M. Harrod. The Vital Force. A Study of Bioenergetics. (New York: W.H. Freeman, 1986). p. 187.] Roughly, the earliest bacteria appeared on this planet three and a half billion years ago scavenging the products of non-biological chemical processes; a billion years later they evolved the capacity to tap into the solar gradient, producing oxygen as a toxic byproduct; and one billion years after that they evolved the capacity to use oxygen to greatly increase the efficiency of energy and material consumption. By contrast, the great diversity of multicellular organisms that populate the planet today was generated in about six hundred million years. Thus the history of the earliest biosphere is a narrative of how the capacity of the environment to sustain life was extended by the discovery through evolutionary search of the biochemical circuitry needed for fermentation, photosynthesis, and respiration. (Delanda 2011:61)

In populations of disembodied replicators there is only one parameter affecting the identity of assemblages. But with the emergence of the genetic code and the acquisition of a minimum of embodiment through encapsulation within a membrane, identity could now be defined in two different ways. As we saw in Chapter 5 the behavior of all ancient organisms was rigidly determined by their genes, that is, they could only learn as a species over many generations, so the coding parameter had a fixed high value for several billion years. But the territorialization parameter could change and lead to different types of behavior. Early bacteria lacked the ability to move and tended to form colonies that accumulated as layers at the interface between water and bottom sediments. To a casual observer these bacteria would have looked just like another sedimentary layer, motionless and unchanging in its anatomy, that is, very territorialized. But enormous changes were taking place within their membranes as the machinery to tap into external gradients slowly evolved. Starting with the chemical machinery behind fermentation these creatures learned how to tap into the solar gradient using photosynthesis and how to greatly increase the energy that could be produced from earlier methods using oxygen. These evolutionary achievements were veritable metabolic deterritorializations. The first mobile predators emerged and were able to break away from a behaviorally territorialized life thanks to the fact that they did not have to develop their own capacity to drive metabolic processes away from equilibrium: they simply absorbed bacteria as a whole developing a symbiotic relationship with them. (Delanda 2011:175-6)

DELANDA, Manuel. 2011. Philosophy and Simulation: The emergence of Synthetic Reason. Londres: Bloomsbury Academic.