5.1 Knowledge Systems for Adaptation and Defence (SADS).
Living creatures have, during their evolution, acquired an implicit knowledge of their environment. They have, by selective pressures in the flow of many generations, been shaped to respond sensibly to their usual environment. This biological process has led to phylogenetic (ancestral) cognition. Cognition is expressed in the body-forms and -functions that exactly fit their environment:
the wings of birds carry information about the density of air. Ever since their reptilian ancestors did acquire wings birds have been the experts for air-transport
the flight muscles of insects are equipped for the rapid oscillations of insect wings that are so much smaller than birds wings. The production of such oscillations has been a special field of study by J.Pringle (see Appendix)
the fins of fish have during their formation acquired knowledge of the density of water, and so are equipped for motion in their particular environment
the sensory functions of animals and their feeding behaviours reveal that, during phylogeny, they have acquired the necessary knowledge about their usual sources of food.
By using the word 'cognition' to stand for 'knowledge embodied in structure and functions', we borrow from the sciences of the mind. Cognition is ordinarily used for mental processes such as perception, memory and thinking in the higher primates. In the present context cognition is used in the broad biological sense of "wisdom of the body", as expressed in its form and function, and as acquired in the course of evolution by the Genetic System for Adaptation and Defence (GAD). The meaning of cognition is thus transferred from the time-scale of human life events (minutes - years) to that of the evolutionary time-scale (centuries-aeons). J. Lovelock (1988) has gone even further and has described the entire biosphere, including the planet Earth itself, as one living organism (Gaia) with a cognitive network that touches and includes everything.
Extending the meaning of the term 'cognition' is a step towards reintegrating the sciences, and should be recommendable for that reason. Another example of extending the meaning of a word is the use of 'learning' for 'improved responding to environmental challenge on the basis of experience'. We are used to think that learning takes place in the brain. The immune or lymphoïd system for adaptation and defence (LAD) however is as such a complete learning system on another level. It has a memory that is extended by experience, and it keeps its internal representation of the environment up to date by adding to its knowledge. It also has a value system: an immune system that enables the individual to assess its material environment and so to interact with it for food and protection. In cooperation with the nervous system it discriminates what can be taken in and what is to be avoided.
In the course of evolution plant and animal species are forever improving their means to protect their integrity, to maintain and multiply themselves. The learning process in the evolutionary time scale is augmented by learning in the lifetime of the individual animal (ontogenetic learning). The difference between plants and animals in this respect is that plants have too little memory storage to learn much during one single lifetime; however they learn relatively fast in the evolutionary time scale, as appears from the abundant varieties of wild and cultivated plants.
Learning in an individual animal's life time resembles evolutionary learning, except for the time-scale. In immune and neural learning, Darwinian processes of variation and selection take place at a rapid rate. The generations of lymph-cells and neuronal components follow each other at a high rate, so that selections can take place at short intervals. Immune globulins are produced by the millions every second. The rate of learning is immense: the immune system (LAD) responds to change a million times and the nervous system (NAD) even a billion times faster, than the response rate in the time-scale of evolution of an animal species.
This fruitful application of evolution theory to shorter time-windows is lost on S.H.Nasr, professor of philosophy and sciences at the university of Teheran. In an article in Unesco Courier he declares that the theory of evolution is no more than a parody of the traditional gradation concept. Why a parody? This theory has revealed so much about nature, including human nature, that it has obliged scientists everywhere to revise their philosophy. Some people are afraid to do that. A parody? Darwinian evolution is the fulfilment of everything a gradation theorist could wish for!
The two systems within the vertebrate body that are open to evolutionary processes i.e. the lymphoid and the neural system, develop their adaptive memory-content during the individual's lifetime. In this way they foster appropriate behaviour in response to new stimuli. Such is the surprising solution of the enigma of learning: by varying the cellular and humoral output and selectively reinforcing the most fitting elements the best adaptive responses are fostered. The lymphoid system and the neuronal system belonging to one and the same organism, form part of each other's environment and as such influence each other's path of learning.
the immune or lymphoid system (LAD) handles information of a physico-chemical nature,
the nervous or neuronal system (NAD) handles information of perceptual, emotional and behavioural nature.
That these two systems work closely cooperate is the more fascinating since they are so different in form and substance. The immune system is for the greater part fluid, although thymus and bone-marrow and spleen provide a kind of substance; the brain is for the greater part solid. During the foetal stage nerve cells can migrate freely from one place to another, directed by similar fields of attraction as exerted by the lymphoid cells of the immune system. During it's whole life the brain restructures it's information content, even more freely than the lymphoid system does.
The two systems, LAD and NAD, enable individuals to regulate their interactions with the environment. Although the central nervous (neural) system responds a thousand times faster than the immune (lymphoid) system both systems have many properties in common:
both develop and maintain the two-way communication between the genetic core of an individual and it's environment (Map 5.2.2)
the communication-trajectory in the signal-exchange between an organism and it's environment is of a physico-chemical nature
the systems synthesise a large amount of protein, which they use for replacement of old molecules by new ones. Continuous replacement is a clever way to combine a permanent structure with an almost unlimited plasticity of function
both have a hierarchically organised (concentric) information processing system.
Some messengers in the immune system have a relatively short response time, that comes near the time-window of slow-acting neural components belonging to the autonomous system. Because systems that oscillate in closely corresponding frequencies influence each other, the immune and nervous systems interact, via hormones and other pathways of the autonomous system. A similarly mediated interaction is discussed with relation to epigenesis and metabolism in chapter (3) on Embryogenesis.
Throughout the vegetal and animal kingdoms chemical signals are active, as internal messengers or as messengers between plants and animals, as attractants or repellents. In higher animals and man the "chemical" senses remain active in receiving and transmitting vital information. Tastes and smells are detected by scanning and recognising the molecular surface configurations of odorants, in a similar way as antibodies recognize antigens. Recognition leads to depolarisation of neurons in the olfactory epithelium. The signals are decoded by the "rhinencephalon", a phylogenetically ancient drive and motivation centre that is a part of the limbic system of the brain's cortex. Odours can act as pheromones, also in humans. They often give rise to strong motives and to immediate, partly involuntary action.
5.2 A Sphere of Life in an ocean of uncertainties. Synergy guides growth.