The Ghost in the Machine (18 page)
hierarchy is part of the price paid for differentiation and specialisation.
The price is of course worth paying so long as the individual lives
under fairly normal conditions, and can safely rely on his more or less
automatised routines. But conditions may arise when this is no longer
the case, and it becomes imperative to break with routine.
The Challenge of Environment
This brings us to a point of vital importance which I have so far not
mentioned: the influence of the environment on the flexibility or rigidity
of behaviour.
If a skill is practised in the same unvarying conditions, following the
same unvarying course, it tends to degenerate into stereotyped routine,
and its degrees of freedom freeze up. Monotony accelerates enslavement
to habit; it makes the rigor mortis of mechanisation spread upward in
the hierarchy.
Vice versa, a changing, variable environment demands flexible behaviour,
and reverses the trend towards mechanisation. The skilled driver on the
familiar road from his home to his office hands over to the automatic
pilot in his nervous system, while his thoughts are somewhere else; but
if he gets into a tricky traffic situation, he will suddenly concentrate
on what he is doing -- the man takes over from the computer. However,
the challenge of the environment can exceed a critical limit where it
can no longer be met by skilled routine, however flexible -- because
the customary 'rules of the game' are no longer adequate to cope with
the situation. Then a crisis arises. The outcome is either a breakdown
of behaviour -- 'when in danger or in doubt, run in circles, scream and
shout'. The hierarchy has disintegrated. The alternative possibility is
the sudden emergence of new forms of behaviour, of original solutions --
which, as we shall see, play a vital part in both biological evolution
and mental progress.
The first possibility is demonstrated by the cat which, unable to comply
with the strict rules of its canon of hygiene, goes through the pointless
motions of trying to bury the mess under the hard kitchen tiles. Human
beings in a crisis are capable of equally senseless behaviour, repeating
the same hopeless attempts to get out of it.
The alternative possibility is demonstrated by the unexpected
improvisations of the digger-wasp, the reorganisation of labour in the
mutilated beehive -- or a chimpanzee breaking a branch from a tree to
rake in a banana beyond the reach of its arm. 'Original adaptations'
of this kind, to meet challenges of an exceptional nature, point to
the existence of unsuspected potentials in the living organism, which
are dormant in the normal routines of existence. They foreshadow the
phenomena of human creativity, to be discussed in
Chapter XIII
.
Summary
On successively higher levels of the hierarchy we find more complex,
flexible and less predictable patterns of activity, while on successively
lower levels we find more and more mechanised, stereotyped and predictable
patterns. In the language of the physicist, a holon on a higher level of
the hierarchy has more degrees of freedom than a holon on a lower level.
All skills, whether derived from instinct or learning, tend with increasing
practice to become mechanised routines. Monotonous environments facilitate
enslavement to habit; while unexpected contingencies reverse the trend,
and may result in ingenious improvisations. Critical challenges may lead
to a break-down of behaviour or to the creation of new forms of behaviour.
The higher echelons in a hierarchy do not normally communicate directly
with lowly ones, but through 'regulation channels', one step at a
time. A short-circuiting of intermediary levels may cause disorders of
various kinds.
Part Two
BECOMING
IX
THE STRATEGY OF EMBRYOS
Benjamin Franklin's reply to a lady who queried the usefulness ofThe classical Darwinian answer to the question how man was created
his work on electricity: 'Madam, what use is a new-born baby?'
out of a blob of slime is much the same as Watson's answer to the
question how Patou creates a gown out of a piece of silk: 'He pulls
it in here, he pulls it out there, makes it tight or loose at the
waist. . . . He manipulates his material until it takes on the semblance
of a dress. . . .' The evolutionary process is supposed to operate by
similar random manipulations of its raw material -- pulling it in here,
pushing it out there, putting a tail on here, putting an antler there --
until 'a pattern is hit upon', fit to survive.
Flat-earth science explains mental evolution by random tries, preserved
by selective reinforcement (the stick and the carrot), and biological
evolution by random mutations (the monkey at the typewriter) preserved by
natural selection.
Mutations
are defined as spontaneous changes
in the molecular structure of genes, and are said to be
random
in the sense that they have no relation whatsoever to the organism's
adaptive needs. Accordingly the great majority of mutations must have
harmful effects, but the few lucky hits are preserved because they
happen to confer some small advantage on the individual; and given
sufficient time, 'anything at all will turn up'. 'The hoary objection',
Sir Julian Huxley wrote, 'of the improbability of an eye or a hand or
a brain being evolved by "blind chance" has lost its force' -- because
'natural selection operating over the stretches of geological time'
[1] explains everything.
In fact, however, the hoary objection has been steadily gaining in force
during the mid-century decades -- so much so that there is hardly a
prominent evolutionist alive who has not expressed some heretical views
concerning some particular aspect of the orthodox doctrine -- while
staunchly rejecting the heretics of others. Although these criticisms
and doubts have made numerous breaches in the walls, the citadel of
neo-Darwinian orthodoxy still stands -- mainly, one supposes, because
nobody has had a satisfactory alternative to offer. The history of science
indicates that a well-established theory can take a lot of battering and
get into a tangle of absurdities and contradictions, yet still be upheld
by the Establishment until an acceptable global alternative is offered.*
But historically the only serious challenge to neo-Darwinism came from
Lamarckism; and Lamarckism had much valid and scathing criticism, but
no constructive alternative to offer.
* See Thomas Kuhn's thesis of 'Paradigm-Change' [1a], and the chapterIndeed, for nearly a hundred years, the theorists of evolution have
on 'The Evolution of Ideas' in The Act of Creation.
been fighting an embittered Civil War of Lamarckian Roundheads versus
Darwinist Cavaliers. The actual dispute was of a complex, technical
character; but it was highly charged with metaphysical, emotional and
even political implications. In the Soviet Union, the Darwinian Cavaliers
were summarily sent to labour camps under Stalin, and the survivors
summarily rehabilitated under Khrushchev: an episode known as the 'Lysenko
affair'. The main issue -- over-simplified and put in a nutshell -- is
this: Lamarck believed that the adaptive modifications of physique and
ways of life, which an animal acquires to cope more effectively with its
environment, are transmitted by heredity to the offspring ('inheritance
of acquired characteristics'). Thus if a boxer develops strong muscles
by training, then his son, according to Lamarck, ought to be born with
strong muscles. This would provide a sensible and reassuring view of
evolution as the cumulative result of learning through experience and
training for a better life; but unfortunately, as so often happens, the
commonsense view turned out to be inadequate. To this day, in spite of
great efforts, Lamarckism has failed to produce conclusive evidence to
prove that acquired characters are transmitted to the offspring; and
it seems fairly certain that, while experience does affect heredity,
it does not do so in this simple and direct way.
But the failure of Lamarckism in its primitive form does not mean that
the monkey at the typewriter is the only alternative to choose. Random
mutations, preserved by natural selection, without doubt play a part in
the evolutionary process -- just as lucky coincidences play a part in the
evolution of science. The question is whether this is the whole truth,
or even the most important part of the truth.
A number of corrections and amendments to neo-Darwinian theory have been
proposed by evolutionists over a number of years; and if these were to
be put together, there would be little left of the original theory --
as amendments to a Parliamentary bill can reverse its emphasis and
intent. But, as already said, each critic had his particular axe to
grind, with the result that ''Tis all in pieces, all coherence gone' --
as John Donne lamented when medieval cosmology was landed in a similar
crisis. In this and the next three chapters I shall collect some of
these bits and pieces, and attempt to fit them together.
Docility and Determination
It takes fifty-six generations of cells to produce a human being out
of a single, fertilised egg-cell. This is done in a series of steps,
each of which involves (a) the multiplication of cells by division,
and the subsequent growth of the daughter-cells; (b) the structural
and functional specialisation of cells (differentiation); and (c) the
shaping of the organism (morphogenesis). Needless to say, all three are
complementary aspects of a unitary process.
Morphogenesis proceeds in an unmistakably hierarchic fashion. The
development of the embryo from a shapeless blob to a roughed-in form, and
through successive stages of increasing articulation, follows the familiar
pattern described in previous chapters; I have mentioned the analogies
with the sculptor, who carves a figure out of a block of wood, and with
the spelling out of an amorphous idea into articulate phonemes. The
step-by-step differentiation of cell-groups up to their ultimate
specialisation presents the same hierarchically arborising picture:
(after Clayton [2]). Diagram of some of the pathways open to earlyThe diagram schematises some of the developmental possibilities of the
ectoderm in the amphibian embryo. Three only of the many inductive
relationships are indicated by arrows.
ectoderm in the amphibian embryo. (The ectoderm is the outermost of the
three layers of cell-populations into which the embryo differentiates
at an early stage; the other two are mesoderm and endoderm.) The arrows
on the left side of the diagram indicate the action of certain adjacent
tissues ('inducers') which, when brought into contact with the ectoderm,
act as
chemical triggers
on it. Those regions of the ectoderm which
are in direct contact with the inducer-tissue will differentiate by stages
into the animal's nervous system, including brain and eye-cups. Other
regions of the ectoderm will, owing to their different surroundings,
specialise in other ways. If a cell-population develops into 'skin', it
may further specialise into sweat glands, horny layers, and so on. At
each step biochemical
triggers
and
feedbacks
determine
which of the alternative developmental pathways among several possibles
a group of cells will actually follow.
Thus, when the eye-cups (the future retina), which grow out of the
brain at the end of two stalks (the future optic nerves), make physical
contact with the surface, the skin over the contact area folds into the
concave cups and differentiates into transparent lenses (see arrows on
the fight of the diagram). The eye-cup induces the skin to form a lens,
and the lens in its turn induces adjacent tissues to form a transparent
horny membrane, the cornea. Moreover, if an eye-cup is transplanted under
the skin on the belly of a frog embryo, the skin over it will obligingly
differentiate into a lens. We may regard this obligingness or 'docility'
of embryonic tissue, its readiness to differentiate into the kind of
organ best suited to the tissue's position in the growing organism, as a
manifestation of the
integrative tendency
, of the part's subordination
to the interests of the whole.
But 'docility' is again only one side of the picture; the other
is 'determination'. Both are technical terms. 'Docility' means the
multipotential capacity of embryonic tissue to follow this or that branch
of the developmental hierarchy according to circumstances. But along
each branch there is a point of no return, where the next developmental
stage of the tissue is 'determined' in an irreversible way. If, at the
earliest, so-called 'cleavage stage' of its development, a frog-embryo
is split into two, each half will develop into a complete frog, not, as
it normally would, into a half frog. At this stage each cell, though it
is a
part
of the embryo, has retained the genetic potential to grow,
if need be, into a
whole
frog -- it is a true, Janus-faced holon.
But with each step of development along the branching tree, the successive
cell-generations become more specialised, and the developmental
'choices' before a given cell-tissue -- its genetic potential --
become more and more restricted. Thus a piece of the ectoderm may
still have the potentiality to develop into a cornea or skin-gland,
but not into a liver or lung. Specialisation, here as in other fields,
leads to a decrease in flexibility. One might compare the process with
the series of curricular choices which face the student, from the first
broad alternative between Science and the Humanities, to the final
'determination' which turns him into a marine zoologist specialising
in echinoderms. At each point of decision, where the pathways diverge,
some minor hazard or incident may act as a trigger which 'induces' him
to make this or that alternative choice. After a while, each decision
becomes to a large extent irreversible. Once he has become a zoologist,
there are still numerous pathways of specialisation open to him; but
he can hardly retrace his steps and become a barrister or a theoretical
physicist. Here, too, the 'one-step rule' of hierarchies applies.
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