Table of Contents
Part IV: The Survival of the UN-fit
Natural Selection: Fact or Fancy?
Is Nature Really
in a Constant State of Warfare?
IT IS truly amazing how, once an idea
has seized the public mind because it suits the temper of the
times, it is almost impossible to dislodge it. It must have been
apparent to millions of ordinary people who had any firsthand
knowledge of Nature at all that the picture proposed by Darwin
of a state of chronic warfare was completely unreal. Obviously,
Nature has not essentially changed since Darwin's time, so the
behaviour we see in the open country, whether in Canada or England
or Africa, is what it was in those days. And we do not
see animals constantly battling with each other. The supposed
"struggle" for existence is comparatively mild. Animals
establish their territories rather with enthusiasm than viciousness.
Nature is far from "red in tooth and claw," as Tennyson
1 of 13
of the first naturalists who had the opportunity to study Nature
at first hand over a period of many years was the Russsian prince
Petr Kropotkin. Petr was born in Moscow in 1842 and came of a
family belonging to the highest stratum of Russian aristocracy.
His home life was filled with love and gentleness, and though
his mother died when he was very young, her extraordinary gentleness
and affection stayed with her children all their lives. Although
his father owned very many serfs, it is evident that they were
always treated with exceptional kindness, and Petr himself in
his writings again and again returns to the gentility and great-heartedness
of these common people. He was educated for a military career,
but his real interests were in geography, zoology, botany and
anthropology -- more particularly with special reference to Siberia.
So Petr sought and obtained a commission in a Siberian regiment
where he seems to have spent more time in the study of nature
than in the study of warfare. Indeed, his work in zoology from
1862 to 1866 is consideered outstanding.
the influence of Darwin's Origin of Species, which had
come into his possession a little while before he went to Siberia,
tells us in the very first paragraph of his book how eagerly
he looked for "that bitter struggle for the means of existence
among animals belonging to the same species, which was considered
by most Darwinists (though not always by Darwin himself) as the
dominant characteristic of the struggle for life, and the main
factor of evolution."
book to which reference is made above is his Mutual Aid,
which was published by Kropotkin in 1902. (17) This appeared
first as a series of articles in the English journal The Nineteenth
Century, the first installment appearing in 1890. The book,
in which these papers were bound together, appeared subsequently.
It should be carefully borne in mind that this work was the result
of close observation in Nature, observation initially stimulated
by a search for evidence to bear out Darwin's thesis that a constant
struggle went on between living forms. The result, however, was
a total repudiation of the whole concept of struggle.
first he found himself in an area where there was no pressure
of numbers, where there was a paucity of life, where under-population,
not over-population, was the distinctive feature of the area.
Here he found that there was no "fearful competition for
food," which was an article of faith with most Darwinists.
So he attributed his failure to validate Darwin's basic thesis
to the fact that there were too few animals in northern Asia
to fulfill the requirements of adequate competitiveness.
when he sought out particular localities in which there was a
super-abundance of animals, he found that even here there was
no evidence of the kind of struggle which Darwin postulated:
I saw animal life in abundance, as for instance, on the lakes
where scores of species and millions of individuals came together
to rear their progeny; in the colonies of rodents; in the migrations
of birds which took place at that time on a truly American scale
along the Usuri; and especially in a migration of fallow-deer
which I witnessed on the Amur, and during which scores of thousands
of these intelligent animals came together from an immense territory,
flying before the coming deep snow, in order to cross the Amur
where it is narrowest � in all these scenes of animal life
which passed before my eyes, I saw Mutual Aid and Mutual Support
carried on to an extent which made me suspect in it a feature
of the greatest importance for the maintenance of life and the
preservation of each species. . .
It should be noted that Kropotkin
still believed this kind of mutual aid did contribute to "further
evolution." He was quite convinced
17. Kropotkin, Prince Petr,
Mutual Aid, Extending Horizon Books, Boston, 1955, Introduction,
18. Ibid, p.viii.
main thesis was correct, but his own observations continually
and in every way, and most emphatically, drove him to the conviction
that struggle in itself did not lead to improvement. Indeed,
struggle, when it became critical due to local famine had the
effect only of impoverishing the animals involved, both
in vigour and in health, so that, as he said, "No progressive
evolution of the species, can be based upon such periods of keen
found himself forced to reject completely the view that competition
was essential to improvement: (20)
persuaded that to admit a pitiless inner war for life within
each species, and to see in that war a condition of progress,
was to admit something which not only had not yet been proved
but also lacked confirmation from direct observation.
Kropotkin was quite willing to admit
that there is within each species a certain amount of real competition
for food "at certain periods." But he was very doubtful
from his own studies at first-hand in over-populated areas where
the competition is carried on to the extent argued by Darwin,
whether what competition there was played the part assigned
to it in the evolution of the animal kingdom. He felt that Darwin
was weakest when dealing with this point, which was, after all,
so crucial to his whole thesis. So he wrote: (21)
refer to his paragraph entitled, "Struggle for Life most
severe between Individuals and Varieties of the same Species,"
we find in it none of that wealth of proofs and illustrations
which we are accustomed to find in whatever Darwin wrote. The
struggle between individuals of the same species is not illustrated
under that heading by even one single instance [my emphasis]:
it is taken for granted; and the competition between closely
allied species is illustrated by but five examples, out of which
one at least (relating to the two species of thrushes) now proves
to be doubtful.
So, Kropotkin asked, "To what
extent does competition really exist within each animal species?
Upon what is the assumption based?" And his whole book is
a striking demonstration of the doubtfulness of Darwin's basic
proposition in this respect. Yet so powerfully had Darwinism
captured public imagination that very few people were either
aware of or paid the slightest attention to Kropotkin's writings.
Nevertheless, what he reported has continued to be of such interest
that Mutual Aid has constantly been reprinted and is constantly
running out of stock. (The latest reprint apparently was undertaken
in 1972 by the New York University Press.)
19. Ibid., p.ix.
21. Ibid., p.61.
This happy practice of reprinting some of the older
works has fortunately helped to offset the distressing tendency
of publishers of new works to favour only the printing of pro-evolutionary
literature, a not unnatural reaction to public demand, since
they have to stay in business by making a profit. But it has
had the unhappy effect of confirming in the public mind the supposition
that there is nothing to be said against evolution.
Do Animals Really
Overpopulate Their Territory?
Kropotkin's work stimulated others to take a fresh look at the
evidence. And some of these, even though they remained confirmed
evolutionists, nevertheless produced works, the cumulative effect
of which must in the end serve to undermine the whole evolutionary
fabric. I am thinking, for example, of W. C. Allee's book, The
Social Life of Animals, a work which as might be supposed
from its title, (22) sets out to demonstrate from evidence
acquired since Kropotkin's time that Nature is not a series of
warring states but a remarkably well-balanced cooperating society
of animals and plants.
this last work and in another book of similar nature entitled,
On Being Human, by Ashley Montagu, we may find an answer
to another question asked in the previous chapter. (23)
people, when they go to see pictures of animals in the wild,
expect to see large numbers. So animal photographers not unnaturally
take their cameras where the animals are numerous. The consequence
is that one inevitably has an impression of "the wild"
as teeming with animal life. In the Rockies we imagine that everywhere
there are flocks of mountain goats or other such creatures; in
Africa vast herds of zebra, giraffe, and even elephants. In point
of fact, this impression is the result very largely of selective
photography. So also, the inexperienced camera-man or the impatient
amateur comes away with one or two pictures showing a few animals
together � only after days of searching and a substantial
number of false alarms leading to wasted footage. Even where
man has not been the most common predator and where the fear
of him has not spread the alarm upon his approach, it is likely
to be the occasional animal, the curious and unafraid, which
will provide the amateur naturalist with his best opportunity.
fact is that very few parts of the earth are in any way
22. Allee, W. C., The Social
Life of Animals, Beacon Hill Press, Boston, 1938, p.233.
23. Montagu, Ashley, On Being Human, Schuman, New York,
with animals. The total number of birds per acre in most parts
of the world is very small and has been calculated out by weight
as being only a few pounds. Thus there may be a number of very
small birds whose total weight is a few pounds, or one or two
larger ones whose total weight is about the same. But the density
of individuals is very low. This is not true, of course, where
a small island standing alone as a refuge in a vast expanse of
ocean is occupied by tremendous number of birds or other shoreline
animals. For here the population per acre must take into account
the territory over which these animals feed � which is, of
course, far greater than the area of the island itself. It should
also be remembered that in terms of freedom of movement birds
enjoy a third dimension of dispersion, altitude.
is not to deny that birds flock together in vast numbers, a fact
which would seem to challenge the available food supply. Nevertheless,
there is very little fighting among such flocks unless they are
hedged in by man. And even here, as has been shown for geese,
when the animals are resting they will orient themselves as far
as possible so that each individual has a certain minimal free
space, or "facial distance" as it has been called,
in front of it. (24) And though it may take some time
for a large flock to settle down in this way, the birds respect
this "individual need" and avoid conflict. Even if,
due to a wire fence, crowding is extreme, it has been noted that
the peripheral individuals will all turn outwards taking up a
position which allows them to achieve the required facial distance
by looking through the wire fence and thus give the central birds
a better chance to achieve a position of no conflict. It seems,
therefore, that even under unnaturally stressful conditions most
animals will do all they can to keep the peace.
to man's interference, it appears that Nature is seldom crowded.
But wherever man has gone, he has been Nature's great disturber,
either exterminating animals entirely or forcing them to crowd
together unnaturally. Among species in which internicene warfare
has been observed, rats are probably pre-eminent. Yet rats are
in a special category, since they spread with man and compete
chiefly where men are crowded together. Due to historical circumstances,
therefore, it has often come about in the past that man's chief
acquaintance with behaviour patterns within species of animals
other than himself has been badly distorted because of his own
influence on these same species. In former times the rat population
24. McBride, Glen, "The
Conflict of Crowding," Discovery, April, 1966, pp.16-19.
greater than it now is, and city people commonly derived their
picture of Nature from these unnaturally congested creatures.
crowding and its accompanying competition is not characteristic
of animals in the wild, even where the environment might be expected
to encourage it because of its abundant food supply. Kropotkin's
initial researches were conducted in Siberia, which did not seem
to him to constitute a sufficiently favourable environment for
large numbers of animals. Nevertheless, he noted that many regions
enjoying a far more congenial climate than Siberia are equally
under-populated. For example, along the shores of the Amazon
River, in spite of the fact that food is plentiful as evidenced
by the great variety of mammals, birds, and reptiles, these are
very widely scattered, and it is only rarely that animals are
seen in any numbers. The fact is even more strikingly observed
in the forests of Brazil which afford ample food for birds and
yet, like the forests of Asia and Africa, are not over-populated
but rather under-populated. (25)
The same is true, according
to Kropotkin, of the pampas of South America, which, although
so admirably suited to herbivorous quadrupeds, affords the observer
with an astonishingly small number of visible animals. Indeed,
to one observer, W. H. Hudson, only one small ruminant was seen
in this immense grassy area. Land birds are also few in species
and numbers. By contrast, millions of sheep, cattle, and horses
introduced by man now graze upon a portion of these prairies.
areas can, under human husbandry, support far larger populations
of animals clearly suggests that the numbers to be found there
naturally are not being held down by competition. Nature does
not naturally over-populate; if anything, it under-populates.
so, many years after the publication of The Origin of Species,
the average city dweller still has the impression that every
inch of ground is teeming with life in such a way that there
is constant conflict between individuals for the available food
supply. The country man, on the other hand, is well aware of
the fact that for almost all species the distribution is sparse,
thinly spaced. One may have to search to find a live representative,
and as a rule one would have to scrutinize the area keenly to
find any dead animals.
if Darwin's picture had any truth behind it, the open country
ought to be teeming with competing animals and the competition
itself ought to result in many corpses lying around. Moreover,
among those species which are highly gregarious, such as
25. Kropotkin, Prince Petr,
Mutual Aid, Extending Horizon Books, Boston, 1955, pp.309,
in a local warren, or gophers, or any creatures which are found
in comparatively large numbers here and there, there is no evidence
whatever that their crowding has in itself led to a progressive
change in form. Yet, according to Darwin, the consequence of
this crowding should be just that, namely, progressive change,
leading to improvement of the species as a whole. It sounds reasonable
enough, but what has become more apparent as research among natural
communities of this kind has been extended, is that such competitive
crowding has precisely the opposite effect than was supposed
by Darwin. It leads to the elimination of the extremes and the
perpetuation of the norm. The odd or exceptional individuals
tend to be either destroyed or bred out by being overwhelmed
by the sheer numbers of the common types. Leo Berg, after a discussion
of the imagined effects of the supposed struggle for existence
pointed out that careful students of nature he (26)
. . . could not observe any perceptible
difference between the individuals which have survived and those
which have perished. As far as may be judged from the available
data, natural selection cuts off deviations from the standard
by destroying extreme variations [his emphasis].
He then gave some illustrations from
both animals and from plant species, and concluded: (27)
foregoing renders it doubtful whether mortality in natural conditions
possesses selective value, i.e., is contributing to evolution:
as a rule, individuals approaching the standard survive, and
all those which deviate therefrom perish, no matter whether their
distinguishing characters are retrogressions or give promise
of being able to advance.
in natural conditions thus not only does not assist evolution
but appears in fact to be a hindrance thereto.
Such an opinion
was held by Korshinsky: "The struggle for existence, and
selection connected with it, is an agency tending to restrict
the development of forms already produced by checking further
variations, but never contributing to the production of new forms.
It is a principle antagonistic to evolution."
Some years ago the animal ecologist
Charles Elton pointed out that this absence of evolutionary change
in crowded areas applies equally to plants. He wrote: (28)
certain intertidal communities of the sea do we find that animals
have reached the limits of space that will hold them. . . .
26. Berg, Leo, Nomogenesis,
Massachusetts Institute of Technology Press, 1969, reprint, pp.63,
27. Ibid., p.64.
28. Elton, Charles: in a report quoted as originating in Nature,
September 23, 1969, but not verified. See also his "Animal
Numbers and Adaptation," in Evolution, edited by
Sir Gavin de Beer, Oxford University Press, 1938, pp.127-137.
are the commonest objects meeting the eye in such spots? The
answer is mussels and seaweed. If there is a struggle for existence,
mussels and seaweed are thus in the very midcentre and vortex
of it. Evolution should here be proceeding at top speed. What
are the facts?
professor J. Ritchie, in his presidential address to the Zoological
Section of the British Association in August, 1939, handed down
the latest bulletin about mussel evolution. He said, "the
edible mussel (Cardium edule) has retained its specific
characteristics for two millions of years or more, its genus
in a wide sense lived 160 millions years ago in the triassic."
And as for the seaweed, those existing
today are not in any way different from those found in Cambrian
and Silurian seas -- which according to the evolutionists themselves
date back to at least 500 million years.
terms of numbers, the prize must certainly be given to insects
where one might therefore suppose that competition would be most
keen and evolution most in evidence. Estimates show that insect
species probably represent half of all species known, and in
terms of total numbers of individuals they are possibly four-fifths
of the world's population. One would expect to find even less
similarity between living specimens and their fossil ancestors
(by reason of the very pressure of numbers) than one finds between
living reptiles and their ancestors, where, because of the smaller
populations involved, there ought to have been very little pressure
towards change. In point of fact, precisely the opposite is the
case. Our reptile world is very different from the ancient world,
but our insect world is remarkably similar, a fact noted by Charles
the picture we get from two surveys spanning the past 70 million
years is that of a decline in primitive types of insects, a gain
in the relative abundance of the specialized orders, and some
substantial changes in the rates of certain groups of the total
population. But by and large the insect population of today remains
remarkably similar to that of an earlier age. All the major orders
of insects now living were represented (with little or no change
indicated) in the Oligocene Forest. Some of the specific types
have persisted throughout the 70 million years since then with
little or no change, indicating a pronounced fixity that gives
little promise of adaptive change in the future. Furthermore,
the insects of that age already showed great variety indeed,
in some groups that we have been able to compare in detail, we
find a greater diversity in the Oligocene insect fauna than in
the present one.
This means simply that there is no
real evidence of progressive diversification into the present.
The truth is that in various ways God seems to have so arranged
things that when severe conflict within a species is imminent,
due to a scarcity of food, migratory instincts
29. Brues, Charles, "Insects
in Amber," Scientific American, November, 1951, pp.60f.
a sufficient number of the community to go somewhere else. The
idea of constant warfare within the species is not borne out.
In fact some creatures, which would have a hard time to migrate
any distance, such as wingless aphids, if raised on an inadequate
diet actually develop wings and fly away.
spread of animals, in so far as it is not accomplished by human
disturbance, is generally assumed to be due to real ovepopulation,
that is, to the pressure of numbers. However, Charles Elton has
of Middleton on the introduced American gray squirrel in England,
and of Harrisson and Hallom on the great crested grebe, also
in England, have shown that spreading takes place equally in
years of abundance and in years of scarcity; in other words,
a great deal of spreading may be due to local movements at the
edge of the range and not to the pressure of numbers in the ordinary
In order to float his theory, Darwin
had to find some basis for selective pressures within a species.
Warfare between species was, he argued, of significance in favouring
animals whose structure gave the predator an edge in powers of
capture, or the preyed-upon an edge in the powers of escape.
This is how the horse got his longer legs, he suggested. But
the real effect of natural selection was supposed to be taking
place within a species as a result of conflict between members
of the same family or herd. But the way in which animals gradually
spread does not support this concept at all, because the so-called
territorial imperative leads rather to the expulsion of unwelcome
members of the species than to their destruction. The expelled
animals merely take up residence somewhere else: they are not
destroyed. Fighting over territory in the vast majority of cases
results in little or no bodily injury, as J. P. Scott put it:
"The occurrence of destructive fighting within a species
tends to be extremely rare." (31)
society in the natural habitat shows very little harmful destructive
fighting, even under conditions of great stress, as when . .
. subjected to general starvation. On the contrary, such societies
exhibit behaviour that would in human terms be called cooperative
or even altruistic.
Moreover, it is not the strong that
throw out the weak as a rule, but the original settler who drives
out the latecomer, and the term
30. Elton, Charles, The
Ecology of Animals, 3rd edition, Methuen's Monographs in
Biological Subjects, London, 1951, pp.71f.
31. Scott J. P.: reviewing "The Natural History of Aggression"
(a reported symposium), Science, vol.148,1965, p.820.
32. Ibid., p.821.
applies equally to later generations, i.e., younger animals.
The courage of an animal is not dependent on its physical fitness,
its size, or its age, apparently, but upon its sense of proprietorship.
So, provided it remains within its home base, a weak unfit specimen
may drive out the stronger, fitter member of its own species.
The term "survival of the fittest" becomes meaningless,
until one defines what one intends in any particular situation
evidence from the study in their natural environment of those
species which are supposed to be nearest to man (gorilla, chimpanzee,
and orangutan) indicates that they do not fight with one another
even for territory. (33)
The impression which Darwin
seems to have had of Nature as a battleground may well have arisen
from the fact that he limited his observations very largely to
animals in captivity. In a recent work by Claire and W. M. S.
Russell entitled (34) Violence, Monkeys and Man,
the authors show very clearly from some fifteen field studies
undertaken in natural conditions that aggressiveness between
monkeys and apes living together is rare. By contrast when the
same species are kept together in captivity, aggression between
cage-mates is frequent and sometimes severe. Evidently, they
conclude, food shortage is not the cause; unnatural crowding
itself would appear to be at the root of the trouble. And animals
see to it that crowding is avoided in Nature, unless it is normal
to the species.
seems clear enough that there is something basically wrong with
Darwin's Malthusian picture of Nature as being in a state of
antagonism as a consequence of the imbalance between the numbers
of animals in any given area and the food supply there. In the
first place, animals for the most part appear to be widely dispersed,
and they maintain their dispersion by territorial instincts which
lead them to defend their home country only by driving away to
a distance unwanted trespassers of their own species. Such trespassers
are not killed as a rule nor even seriously injured. The end
result is that the population density is maintained at a low
level. And yet this does not have the effect of weeding out those
animals which are slightly less capable and favouring those which
are more capable of survival, because the real strength of the
individual to defend his own territory depends not upon his size
or his fitness, but upon his
33. Montagu, Ashley, Letter
to the Editor under the heading "Animals and Man: Divergent
Behaviour," in Science, vol.161, 1968, p.963.
34. Russell, Claire, and Russell, W. M. S., Violence, Monkeys,
and Man, Macmillan, New York, 1968: reviewed by V. Reynolds
under the heading "Cures for Human Violence," in Nature,
January 4, 1969, p.99.
from the geographical center of it. A very superior individual
of any given species trespassing outside his own territory and
into the heart of the territory of an inferior individual of
the same species will almost always be put to rout because, in
Nature, the courage and tenacity of the defendant is normally
found to be far greater than that of the trespasser. This has
been observed and reported time and again. The sickly animal
at home has many times the courage and energy of the trespasser,
bursting with vitality though he may be.
can observe this, if one lives in the country, by studying the
behaviour of little creatures such as chipmunks. The defender
is full of valour the nearer he is to the center of his homeland.
When he chases a trespasser, he has all the edge at first, but
this edge slowly diminishes as the chase carries him further
from the centre. If the trespasser is being chased toward his
own home, he, in turn by contrast, will begin to develop greater
courage until there comes a point at which he is no longer trespassing.
The chase, meanwhile, may have carried the original homeowner
out of his own territory. Suddenly becoming aware of this, his
courage evaporates, he hesitates for a moment, and then somewhat
fearfully turns around and runs back to safety. As soon as this
happens, the original trespasser for a moment is in the ascendant
until the situation has once again reversed. And so one may see
two chipmunks chasing each other furiously nose to tail, A to
B, until the boundary is crossed, and then B to A with the same
vigour until the boundary is crossed in reverse. Robert Ardrey
confidence is at its peak in the heartland, as is an intruder's
at its lowest. Here the proprietor will fight hardest, chase
fastest. That confidence, however, will wane as the proprietor
approaches his border and vanish as he crosses it. Having entered
his neighbor's yard, an urge to flee will replace his urge to
fight, just as his neighbor's confidence and fighting urge will
be restored by the touch of his vested soil.
So these creatures maintain a certain
distance without doing violence to each other by a means which
allows the weak to survive as well as the strong, and the countryside
is not, as a consequence, loaded to the bursting point with animals
competing for the available food. As Ronald Good and many other
naturalists have been pointing out with increasing emphasis in
recent years, Nature is a beautiful system of balanced harmony.
In his review of Natural Communities by Lee R. Dice, Good
notes with satisfaction the gradual
35. Ardrey, Robert, Territorial
Imperative, Delta Books, New York, 1966, p.90.
that is taking place in the interpretation of Nature by more
recent authorities: (36)
and deepest reason for dissatisfaction is our failure to abandon
outmoded biological conceptions, and this has two main aspects.
More important, because of its profound significance to the wild
in general, is what may be called the "nature red in tooth
and claw" fallacy. One would imagine that the influence
that such a belief has had on human affairs in the past half-century
would at least raise doubts about its validity; but even more
odd is the apparent continuing failure to admit that the very
existence of a science of "natural communities" belies
it. For if nature was indeed as the poet (Tennyson) described
it, its condition would be chaotic and in a perpetual state of
disequilibrium. If there is nothing else to thank Dr. Dice for,
there is the support his book gives to the view that nature is
essentially a state of beautiful and delicate balance to which
each and every member makes its due, but only due, contribution.
In the second place, Darwin was quite
wrong in applying certain principles which he derived from Malthus.
Malthus had said, among other things, that animals raise more
offspring than they need to do to maintain their kind. This constantly
challenges the available food supply. But in commenting on this,
Medawar showed its essential fallaciousness: (37)
in this Malthusian syllogism, pointed out years ago by Fisher,
lies in its major premise. So far from producing a vastly excessive
number of offspring, most organisms produce just about that number
which is sufficient and necessary to perpetuate their kind. .
And where, by contrast, there are
tremendous numbers of animals, such as rabbits, insects, birds,
or even fishes, all the evidence points to the conclusion that
among these species there has been virtually no evolutionary
change. So, if evolution has ever occurred, it seems to have
nothing to do with population density or natural aggressiveness
among animals. L. L. Whyte pointed this out:
evolutionary steps, the branching-out into many different types,
seem to have occurred just when the ecological niches were relatively
empty, as in the conquest of land by vertebrates. . . . These
explosive phases seem to have happened when competition was at
a minimum rather than a maximum.
Commenting, Bertalanffy says that
"the identification of evolution
36. Good, Ronald: in a review
of the book by Lee R. Dice, Natural Communities, Ann Arbor,
Michigan, in Nature, July 11, 1953, p.46.
37. Medawar, Sir Peter B., The Uniqueness of the Individual,
Basic Books, New York, 1957, p.14.
38. Bertalanffy, Ludwig von, "Chance or Law," in Beyond
Reductionsism, ref.16, p.68.
adaptation is therefore by no means proved. It is a debatable
point, not an a priori principle of evolution."
Copyright © 1988 Evelyn White. All rights
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