Improbability in the biosphere
Another consideration is that the sort of improbability that Shannon and Weaver write about is not a useful concept for understanding the working of the biosphere.
For Shannon and Weaver, improbability is either improbability vis-à-vis the workings of the entropy law, which we have seen, does not apply to the world of living things, or else it is improbability on the basis of probability theory, which they wrongly take to be the same thing.
In the world of living things, improbability, if we are to use this concept, means improbability vis-à-vis a system’s model or image of its relationship with its environment, which reflects its experience and that of its cultural group (if a human animal) and of its species for a specific purpose – that of assuring the system’s stability vis-à-vis its environment, and hence its survival.
Thus, as living things evolve, they develop the capacity to discriminate between an increasing range of different environment situations, to interpret them correctly and to react to them adaptively. A very simple organism such as the Dyonea Fly-trap that so fascinated Darwin can, when something lands in its trap, do one of two things: close it or not and it does so with the minimum powers of discrimination, since it cannot discriminate between an edible insect and an inedible pebble.
At the other end of the scale is a human animal that can handle a vast number of different signals and interpret them correctly and thereby has at its disposal an exceptionally large repertoire of adaptive responses. In the language of Shannon and Weaver, one can say that the human animal is capable of handling messages with a high degree of improbability and hence of high information value – thousands of bits of information – as contrasted with the mere one bit that the Dyonea Flytrap can handle.
The human animal, however, cannot handle each of these messages with equal ease. Nature is incredibly efficient. The ease with which a living thing can handle messages seems to be a function of their importance or relevance to its behaviour pattern (I shall consider this question in detail further on) and also of the probability, in terms of its own experience and that of its species, that such a message will actually be received.
In other words, information in the brain and nervous system is not arranged at random and hence does not display entropy but is on the contrary highly organised – as is all information made use of by natural systems within the biosphere (genetic information for instance).
This must be so, too, since the behaviour mediated by such information is characterised by its orderliness. The moves that make up a behavioural strategy – such as the development of an embryo in the womb, the bringing up of a child within the family unit, or the cultivation of a garden in a traditional society of horticulturalists, for instance – are not arranged at random. They are highly organised.Back to top
If information is organised, partly at least, in accordance with the probability of its being required, then systems living in a protected environment in which only probable things occur, will need to react adaptively only to a limited range of different environmental situations.
Those that live in a less well protected environment in which improbable things occur, will need to react adaptively to a wider range of more improbable environmental situations – and hence will have to make use of a correspondingly more sophisticated organisation of information, some of which may never have to be used.
Such a system is said to display behavioural diversity and to make use of information whose organization can be regarded as displaying a corresponding degree of diversity.
The behaviour that such diversity permits is referred to by Julian Huxley as “cladogenesis”. Holling refers to a system capable of such behaviour as displaying “resilience”. 
The diversity displayed by a natural system can also be regarded as its ‘redundancy’, or at least its apparent redundancy. It is not a measure of what a natural system does, at least in the short-term, but of what it is capable of doing. It measures all the signals it is capable of handling and all the responses it is capable of mediating, even though during the course of the system’s lifetime it may never have the occasion to exploit more than a minute fraction of these possibilities.Back to top
Redundancy in natural systems
It is astonishing just how much redundancy, in this sense of the term, is built into natural systems. To give an idea; if one of our lungs is destroyed, not only can we survive without it, but we can actually tolerate the destruction of most of the second lung as well. In fact, so long as 6 percent of one lung remains, we can go on living a fairly normal existence.
However, we would no longer be capable of undue exertions. Thus we would not react adaptively to a message which told us to sprint 100 yards at breakneck speed in order to avoid being eaten by a tiger. However such a message, it may he argued, is unlikely to be received.
Lashley [6a] has also shown that we can do very well with but a small part of our neocortex. A gene pool and the population it gives rise to, can also be decimated without bringing about the extinction of the species in question. When a human male ejaculates, he frees something like three hundred million spermatozoa, of these no more than one is required to fertilise a female.
Shannon and Weaver rightly regard a certain amount of redundancy as useful for counteracting the effects of noise. However they take it to be otherwise undesirable in that it reduces the information content of a message by reducing the freedom of choice of the sender and hence the variety of messages he can send.
But in the world of living things, as already mentioned, redundancy should, on the contrary, be identified with the diversity of variety of the messages that can be sent or received; rather than reduce a message’s information content, it must, on he contrary increase it – since it permits the mediation of an essential aspect of behaviour, its ability to adapt to improbable events.Back to top
Information is more than improbability
An even more serious criticism of the extension of Shannon and Weaver’s concept of Information is that it only provides a measure of the improbability of a message (whether it be the right or the wrong sort of improbability). Information, in the world of living things, as I have already intimated is very much more than this. This is also the view of Donald Mackay:
“To dress improbability up as a definition of information as some exponents do, seems the most unfortunate obscurantism. Unexpectedness is a measurable quality or attribute of information – not a definition of it.” 
This is also the view of Brillouin :
“it is naive to take simply the flux of signals per second, to multiply it by bits per signal in the communication engineering sense, and call the result ‘amount of information’ in the sense of transmission of knowledge (labelling everything one does not like, ‘noise’).”
First of all, in the world of living things, a message is not emitted because it is improbable, or, for that matter probable. It is emitted because it is of some relevance to the relationship between the sender and the receiver. Yet Shannon and Weaver are not in the least bit concerned with whether the receiver is interested in receiving a message, let alone whether he can understand it or is likely to believe it – all of which considerations must be of critical importance. Again this may make sense in the world of communications engineering, but not in the world of living things.Back to top
Information and its receiver
As Waddington  points out, information in the real world largely consists of instructions or programmes or ‘algorithms’. Thus, genes combine to provide instructions for protein-synthesis. A gene pool provides instructions for the renewal of a viable population. The brain and central nervous system provide instructions for the proper functioning of an individual’s metabolism and, for his day-to-day adaptive relationships with his environment (neurogeny). A culture provides instructions for the mediation of a society’s adaptive behaviour pattern.
These instructions, and hence this information, are not designed to be transmitted into a random environment. Information, as Brillouin notes, is not something “that can be poured into an empty vessel like fluid or even energy”.  This is one of the most important things wrong with the neo-Darwinist theory of natural selection, in which behaviour is seen as determined by the genes acting in what is taken, implicitly at least, to be a random environment.  
The genes are not dictators, as Weiss  puts it, but “interact in co-operation with the whole of which they are part”. The instructions they issue will only be obeyed by systems that have been programmed by their evolution and upbringing to receive, understand and believe them. This must be true of the transmission of instructions and hence of information in all living processes.
As Waddington writes,
“No transmission system can effectively carry information between a transmitter and a recipient unless the recipient accepts the message as meaningful . . . As the new born infant develops, for instance, it must be ‘moulded’ into an information accepter . . . and an entertainer of beliefs . . . [and] unless this happens the mechanism of information transfer cannot operate.” 
But this is not enough. The receiver of a message must also be structured in such a way as to be capable of acting on the information adaptively. As Waddington writes,
“It is no use pushing the DNA of your sperm into an egg unless the egg contains the polymerases capable of transcribing it into a messenger and all the rest of the machinery for turning out a protein according to specification.”
The cries of a baby in distress provide an important message to its mother who is not only geared to hearing them and understanding their significance but also to responding to them effectively. Otherwise there would be no advantage to be gained from the ability to detect them.Back to top
The quality of a message that will determine whether it will be detected, and interpreted by a natural system is its relevance to its behaviour pattern, or (what is the same thing) its importance to it.
Since information, in a natural system, is organised hierarchically – from the general to the particular – the importance of a message can be determined in accordance with its relevance to the most general and important information contained within a pattern of information or cybernism, which in turn should reflect its relevance to the most important or general phases of the associated system’s behavioural strategy.
Simple forms of life, it can be shown, are only capable of responding to messages which, in the psychological literature, are referred to as ‘stimuli’. Oatley defines a stimulus as
“that aspect of an event of biological importance to a particular animal to which it is sensitive, and by which the response is controlled.” 
This is clearly illustrated, he points out, by the behaviour pattern of the tick as described by Von Uexhull.
“In the tick’s world just three events are important: each is detected in terms of the presence of a single aspect of the situation, and each stimulus to which the tick is sensitive triggers a particular response. Thus when butyric acid is detected in the air, the tick releases its grasp on the branch from which it was hanging. It happens that butyric acid is a chemical secreted by the skin of mammals, and by letting go the branch when it detects this chemical it stands a good chance of landing on the back of a suitable host passing beneath it. Just as the zoologist classifies mammals by whether they suckle their young or have fur, the tick classifies them by whether or not they produce butyric acid. But unlike the zoologist, the tick when it is in the tree is quite insensitive to any other aspect of mammals. The tick is also equipped to detect mechanical stimulation from its host’s hair. This stimulus causes the response of crawling about. Lastly it detects heat, and this causes it to bore into the host’s skin. Thus events relevant to the life of the tick might plausibly be detected simply by receptors sensitive to butyric acid, mechanical stimulation, and warmth.” 
Such receptors will be capable of picking up all messages relevant or important to the behaviour pattern of the tick, the tick simply not being equipped to pick up messages of lesser importance.
The principle involved is clear to someone running a business enterprise. Among other things he must develop the ability to distinguish between the messages he receives that are of importance to his business and those that are not. Since he is likely to have few assistants and must fulfil by himself all the tasks required to assure the survival of his enterprise, he does not have the time to deal with relatively unimportant messages which he must simply ignore.
As natural systems evolve, they develop the capacity to deal with messages of lesser importance as well. This enables them to develop a correspondingly more subtle behaviour pattern which permits them to adapt with greater perfection to their specific environment. Nevertheless it will still be the more important messages with which they are primarily concerned.
To return to the analogy with the managing director of a business enterprise, we would then regard his organisation as having expanded. This means that when messages arrive which are not sufficiently important for him to take the time off to read and act upon, then, rather than simply reject them, he can now delegate them to subordinates at the appropriate ‘echelon of command’.
It is partly at least because our politicians and their scientific and economic advisers have, on the whole, failed to identify the important problems faced by the societies they have been elected to govern (population growth, social breakdown, deforestation, soil-erosion, desertification, pollution etc.) and devoted their time instead to dealing with short-term ‘economic’ triviata, that the world is in such a terrible state.
Nature, on the other hand, has proved very much more efficient. A natural system has a built-in capacity to select messages according to their importance to its welfare and survival and act on them at the appropriate echelon of command and with the appropriate sense of urgency.Back to top
Complexity and diversity
As we have seen in the case of the tick, the simplest informational and somatic organization permits adaptation to important events. On the other hand, that type of informational and somatic organisation which must build up for a system to become capable of adapting to trivial events, I shall take to be its ‘complexity’.
We thus have two types of biospheric organization: diversity, which, as it builds up, permits adaptation, to increasingly improbable events: and complexity, which, as it builds up, permits adaptation to increasingly trivial events.
Both complexity and density contribute to stability. The former by permitting ever more subtle adaptive responses to a specific environment, the latter by permitting adaptive responses (subtle or unsubtle, depending on their complexity) to many different environments.
The greater the instability of the environment, and hence the more it is likely to change, the greater must diversity develop even at the expense of complexity.Back to top
Importance and improbability
There is indeed a necessary connection between the importance and the improbability of messages, but it is not of a nature to justify Shannon and Weaver’s neglect of the concept of importance and their preoccupation with that of improbability.
On the contrary, it would be more accurate to associate the importance of a message with its probability.
From the point of view of a particular species, the most important genes are those that will confer on subsequent generations the most general features of this species, those, for instance, that assure that giraffes look and behave like giraffes rather than like fiddler-crabs or dung-beetles. It is extremely probable that these genes will be present and extremely improbable that the giraffe gene-pool will give rise to populations of such alien beasties.
On the other hand, it is less important and less probable that all giraffes should display the same superficial characteristics, since as we shall see, diversity, in so far as these superficial characteristics are concerned, is the rule rather than the exception.
The same can be said for messages coming from the outside. Living things both adapt to their environment and, at the same time, modify it so that it better satisfies their requirements and thereby becomes easier to adapt to. As this occurs so there is a corresponding increase in the probability of the emission and reception of important messages indicating the presence of those environmental constituents (the presence of food, shelter or the requisite members of the family and community) whose co-operation is required for adaptive behaviour.
At the same time, important messages indicating the presence of events that threaten the generalities of the behaviour pattern of living things (such as famines, epidemics and enemy invasions) must become correspondingly improbable.
The process of adaptation can be represented graphically by reduced discontinuities or fluctuations, corresponding to the building up of increasingly stable relationships between a system and its environment.
If improbable messages are to be identified with important messages – then it can only be with the latter threatening or negative type, rather than with the former co-operative or positive variety.
In fact, the term ‘important’ is far from ideal, as it tends to obscure this critical distinction between messages that are important because they favour an important process, and those are important because they threaten to prevent the occurrence of this process.Back to top
The non-plasticity of general information
Stability is but another word for continuity, and if a system’s behaviour is to be stable or continuous, so must the information in the light of which it is mediated.
The generalities of a system’s behaviour pattern can be shown to reflect its long-term experience; the particularities, its short-term experience.  The former must not thereby be modifiable to satisfy short-term ends – or the system’s basic continuity would be lost. They must, in other words, be non-plastic. It is easy to show that, in normal conditions, this requirement is adequately met.
Thus the genetic information formulated in the language of DNA which is transmitted from one generation to the next, and which provides the most general instructions for the reproduction of a population, is non-plastic in the short-term at least, though the position of science today is that it is non-plastic, even in the long-term.
In the same way, the basic features of a society’s worldview which we associate with its basic values – are also non-plastic. People imbued with these values are not willing to compromise on them; they are taken as given or self-evident. It is because such generalities are non-plastic that the continuity of information, as we have seen, can be maintained.Back to top