Ecological succession rehabilitated

Sequential development

The principle of succession is clearer if it is seen in the light of the general-systems approach. It then becomes apparent that it is not a unique phenomenon as modern ecologists tend to see it, but rather a specialised instance of a very much more general principle, one which is best referred to as ‘sequential development’.

All life processes can be shown to be sequential. This implies that their various stages must occur in the right order, so much so that if one stage is left out, then the succeeding stages will not occur or will occur but imperfectly. It also implies that each stage must occur in the correct spatio-temporal environment, the only one to which behaviour at a given stage is adaptive. Let me make this a little clearer.

All behaviour must be seen as modifying the environment. Such modification is not random from the point of view of the strategy of which the behaviour is an integral part. On the contrary, the new environment will be that which will best serve to trigger off the next stage in the strategy. This does not mean that the whole process is predetermined in a precise way, for at each stage, there may be a large number of possible variants of a basic behavioural response, of which only one or more, are likely in given conditions to be mediated.

There is a third feature of sequential development. It is that it must occur at the appropriate rate. If it is speeded up or slowed down, the end product is unlikely to be optimum. The reason is that any behavioural process or strategy, because of the hierarchical nature of the biosphere, is likely to be part of a larger process or strategy with which it must be correctly synchronised. The inertia, caused by the need to synchronise a process with a host of others, Rupert Riedl refers to as its “burden”. [47]

Piaget is struck by the “sequential character of development”. He defines sequential development as

“une suite de stades dont chacun est necessaire, donc dont chacun resulte necessairement du precedent (sauf le premier), et prepare le suivant (sauf le dernier). Dans le domaine de l’embryogenese des Metazoaires il semble en etre ainsi, puisque les grands stades se retrouvent toujours et dans un ordre constant.” [48]

“A succession of stages of which each is necessary, and therefore of which each inevitably follows from its predecessor (except the first) and pepares the way for its successor (except the last). In the embryogenesis of the Metazoans it appears to be so, because the major stages are always present, and follow in the same order.” [48]

Indeed, because embryological development occurs within a highly protected and ordered environment and because it so obviously constitutes a planned strategy, its sequential nature is apparent to all.

Piaget notes how Waddington explains this in his famous book The Strategy of the Genes. Waddington maintains, according to Piaget, that:

“les actions polygeniques et pleiotropiques du genome ne sont pas a concevoir comme un systeme exclusivement ascendant, mais a chaque étape, de nouveaux genes jusque-la non actifs (quoique naturellement presents des le depart) sont mis en activité par les résultats des actions déjà effectuées par d’autres genes; par exemple le résultat X produit par les genes a, c, et e, active en retour le gene b qui, synergiquement avec a et d produit le résultat Y, qui va activer d’autres genes, etc. Il y a donc la un systeme à boucles, et dont les étages superieurs sont modifiés par le milieu, puisqu’il s’agit du phenotype, mais par un processus selectif ‘sous controle génique’ puisque relatif a ces synthèses successives dependant du genome.”

“the polygenic and pleiotropic actions of the genome should not be thought of as exclusively linear: they are rather iterative, and in each iteration formerly inactive genes (while present from the beginnning) are activated by the results of actions already performed by other genes; for example, result X produced by genes a, c, et e, activates in turn gene b which, synergetically with a and d produces result Y, which goes on to activate other genes, etc. There is thus a bootstrapping process, whose final stages are modified by intermediate stages which express the phenotype, by a selective procedure ‘under genetic control’, because it is relative to these successive syntheses dependent upon the genome.”

Cognitive development in a child also proceeds in a sequential manner. This is unquestionably the view of Piaget who writes

“le problème du caractère sequentiel des stades se retrouve en psychologie pour ce qui est du development des fonctions cognitives et il est important de noter, qu’en ce domaine les stades sont d’autant plus nets et d’autant plus sequentiels que l’on a faire à des regulations mieux differenciées et portant sur un champs plus large.” [49]

“the problem of the sequential nature of stages of development arises in psychology as regards the development of cognitive functions, and it is important to note that in this field the stages are so much more distinct and sequential as to require better differentiated regulations, beaing across a broader field.” [49]

Dr Inhelder, who worked with Piaget for many years, pointed out at Arthur Koestler’s famous Ansbach Symposium that

“learning is definitely dependent upon the subject’s development level. Generally, in all this research, it has been shown that the child never manages to accomplish more than the passage from one sub-stage to the next without ever jumping a stage.”

She also noted that her research now enabled her to answer the often asked question whether it was possible to accelerate the passage from one stage to the next – the answer was clearly ‘no’. Indeed

“if mechanisms in mental development can be compared to what Waddington ‘in embryology’ calls ‘creodes’ or necessary paths with a ‘time tally’, it appears obvious that development always has an optimum rate, neither too slow nor too fast.” [50]

In summing up her views of cognitive development in a child, she stated that

“the research undertaken in Geneva over the last 40 years has brought to light the fact that development does not occur by chance through encounters with the physical and social environment but follows a certain direction. In the development of thought, particularly, there are sequences or stages of progressive structuration. We took this development to obey laws of self-regulation of endogenous origin, but to be subject to continuous modifications under the influence of the feedback resulting from exchanges with the environment.” [51]

In other words, for her, cognitive development is governed by precisely the same laws that govern embryological development. This is not, after all, very surprising since the development of a foetus within the womb and that which occurs after a child is born, clearly form a single process. The notion that they should be governed by different laws is only conceivable because scientific knowledge is arbitrarily compartmentalised and those two sub-processes are thereby studied by separate disciplines.

It is for the same reason too that the idea can be seriously entertained that this wider process is itself radically different from other life processes, such for instance, as the development of an ecosystem. Indeed, at a certain level of generality all life processes must be seen as governed by the same general laws. This is the thesis of Von Bertalanffy’s General Systems Theory and it is a very important one, which few scientists have been willing to face, largely because it is so difficult to reconcile with the reductionist method to which they are so committed.

One such general law is that of sequential development which is known in ecology as ‘succession’. It is equally unacceptable to mainstream science and hence to modern ‘scientific’ ecology – because it implies that life processes are goal directed, highly integrated, indeed linked mutualistically with their environment and come to an end once their goal – the maximum stability or homeostasis possible in the circumstances – has been achieved.

Such a view is also incompatible with the reductionist approach as it is with the scientific dogma that the changes brought about to the biosphere by modern science and technology are anything but destructive and regressive – which they must clearly be seen to be when viewed in the light of holistic ecology.

References

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