The Apparent Gloom Of Darwinism

These considerations suggest that as a developing species we have come to a standstill and have little prospect of further biological advance.

Even if this were so, it need not bother us.

We might survive without any biological change for millions of years, like the crocodiles and many insects. Still from a certain philosophical pain t of view the idea is depressing, and I should like to try and make out a case for the contrary. To do so I must enter on a certain aspect of the theory of evolution which I find supported in Professor Julian Huxley’s well-known book on Evolution, I an aspect which according to him is not always sufficiently appreciated by recent evolutionists.

Popular expositions of Darwin’s theory are apt to lead you to a gloomy and discouraging view on account of the apparent passivity of the organism in the process of evolution.

Mutations occur spontaneously in the genome - the ‘hereditary substance’.

These are due to thermodynamic fluctuation, which is pure chance.

The individual has not the slightest influence on the hereditary treasure it receives from its parents, nor on the one it leaves to its offspring.

Mutations that occur are acted on by ’natural selection of the fittest'.

This again seems to mean pure chance, since it means that a favourable mutation increases the prospect for the individual of survival and of begetting offspring, to which it transmits the mutation in question. Apart from this, its activity during its lifetime seems to be biologically irrelevant.

For nothing of it has an influence on the offspring: acquired properties are not inherited. Any skill or training attained is lost, it leaves no trace, it dies with the individual, it is not transmitted. An intelligent being in this situation would find that nature, as it were, refuses his collaboration - she does all herself, dooms the individual to inactivity, indeed to nihilism.

Darwin’s theory was not the first systematic theory of evolution.

It was preceded by the theory of Lamarck, which rests entirely on the assumption that any new features an individual has acquired by specific surroundings or behaviour during its lifetime before procreation can be, and usually are, passed on to its progeny, if not entirely, at least in traces.

Thus, if an animal by living on rocky or sandy soil produced protecting calluses on the soles of its feet, this callosity would gradually become hereditary so that later generations would receive it as a free gift without the hardship of acquiring it.

In the same way the strength or skill or even substantial adaptation produced in any organ by its being continually used for certain ends would not be lost, but passed on, at least partly, to the offspring.

This view affords a very simple understanding of the amazingly elaborate and specific adaptation to environment which is so characteristic of all living creatures. I t is also beautiful, elating, encouraging and invigorating.

It is infinitely more attractive than the gloomy aspect of passivity apparently offered by Darwinism.

An intelligent being which considers itself a link in the long chain of evolution may, under Lamarck’s theory, be confident that its striving and efforts for improving its abilities, both bodily and mental, are not lost in the biological sense but form a small but integrating part of the striving of the species towards higher and ever higher perfection.

But Lamarckism is untenable.

Its fundamental assumption is that acquired properties can be inherited. But this is wrong.

The single steps of evolution are those spontaneous and fortuitous mutations which have nothing to do with the behaviour of the individual during its lifetime.

And so we are be thrown back on the gloomy aspect of Darwinism.

BEHAVIOUR INFLUENCES SELECTION

I now wish to show you that this is not quite so.

Without changing anything in the basic assumptions of Darwinism we can see that the behaviour of the individual, the way it makes use of its innate faculties, plays a relevant part, nay, plays the most relevant part in evolution.

There is a very true kernel in Lamarck’s view, namely that there is an irrescindable causal connection between the functioning, the actually being put to profitable use of a character an organ, any property or ability or bodily feature - and its being developed in the course of generations, and gradually improved for the purposes for which it is profitably used.

This connection, I say, between being used and being improved was a very correct cognition of Lamarck’s, and it subsists in our present Darwinistic outlook, but it is easily overlooked on viewing Darwinism superficially. The course of events is almost the same as if Lamarckism were right, only the ‘mechanism’ by which things happen is more complicated than Lamarck thought. The point is not very easy to explain or to grasp, and so it may be useful to summarize the result in advance.

To avoid vagueness, let us think of an organ, though the feature in question might be any property, habit, device, behaviour, or even any small addition to, or modification of, such a feature. Lamarck thought that the organ (a) is used, (b) is thus improved, and (c) the improvement is transmitted to the offspring. This is wrong. We have to think that the organ (a) undergoes chance variations, (b) the profitably used ones are accumulated or at least accentuated by selection, (c) this continues from generation to generation, the selected muta- tions constituting a lasting improvement. The most striking simulation of Lamarckism occurs - according to Julian Hux- ley - when the initial variations that inaugurate the process are not true mutations, not yet of the inheritable type. Yet, if profitable, they may be accentuated by what he calls organic selection, and, so to speak, pave the way for true mutations to be immediately seized upon when they happen to turn up in the ‘desirable’ direction.

Let us now go into some details. The most important point is to see that a new character, or modification of a character, acquired by variation, by mutation or by mutation plus some little selection, may easily arouse the organism in relation to its environment to an activity that tends to increase the usefulness of that character and hence the ‘grip’ of selection on it. By possessing the new or changed character the individual may be caused to change its environment - either by actually transforming it, or by migration - or it may be caused to change its behaviour towards its environment, all this in a fashion so as strongly to reinforce the usefulness of the new character and thus to speed up its further selective improve- ment in the same direction. This assertion may strike you as daring, since it seems to require purpose on the side of the individual, and even a high degree of intelligence. But I wish to make the point that my statement, while it includes, of course, the intelligent, purposeful behaviour of the higher animals, is by no means restricted to them. Let us give a few examples:

Not all the individuals of a population have exactly the same environment. Some of the flowers of a wild species happen to grow in the shadow, some in sunny spots, some in the higher ranges of a lofty mountain-slope, some in the lower parts or in the valley. A mutation - say hairy foliage - which is beneficial at higher altitudes, will be favoured by selection in the higher ranges but will be ’lost’ in the valley. The effect is the same as if the hairy mutants had migrated towards an environment that will favour further mutations that occur in the same direction.

Another example: their ability to fly enables birds to build their nests high up in the trees where their young ones are less accessible to some of their enemies. Primarily those who took to it had a selectional advantage. The second step is that this kind of abode was bound to select the proficient fliers among the young ones. Thus a certain ability to fly produces a change of environment, or behaviour towards the environment, which favours an accumulation of the same ability.

The most remarkable feature among living beings is that they are divided into species which are, many of them, so incredibly specialized on quite particular, often tricky performances, on which especially they rely for survival. A zoological garden is almost a curiosity show, and would be much more so, could it include an insight into the life-history of insects. Non-specialization is the exception.

The rule is specialization in peculiar studied tricks which ’nobody would think of if nature had not made them’. I t is difficult to believe that they have all resulted from Darwinian ‘accumulation by chance’. Whether one wants it or not, one is taken by the impression of forces or tendencies away from ’the plain and simple’ in certain directions towards the complicated. The ‘plain and simple’ seems to represent an unstable state of affairs.

A departure from it provokes forces - so it seems - towards a further departure, and in the same direction. That would be difficult to understand if the development of a particular device, mechanism, organ, useful behaviour, were produced by a long pe,arlstring of chance events, independent of each other, such as one is used to thinking of in terms of Darwin’s original conception. Actually, I believe, only the first small start ‘in a certain direction’ has this structure.

It produces itself circumstances which ‘hammer the plastic material’ - by selection - more and more systematically in the direction of the advantage gained at the outset. In metaphori- cal speech one might say: the species has found out in which direction its chance in life lies and pursues this path.