IX. RECENT EVOLUTIONISM
During recent decades the explanatory range of the
doctrine of evolution has expanded, its conceptual
structure has become more intricate, and several fur-
ther attempts have been made to give it a metaphysical
formulation. Evolutionary explanations now occur in
biochemistry, cultural anthropology, and relativistic
cosmology as well as in biology. Classical Darwinism
has been replaced by an enlarged theory of natural
selection which does greater justice to the facts of the
living world. The changes that have taken place in the
history of life are recognized to be extremely complex,
and a corresponding complexity has had to be intro-
duced into the conceptual schemes employed to ac-
count for those changes. At the same time, interest in
schemes of metaphysical evolutionism has continued,
especially among philosophically-minded biologists. A
brief account of these trends will conclude the present
article.
In Darwin's day there was little knowledge of the
causes and the nature of variations which occur in
populations. The laws of heredity were first worked
out by Mendel in 1865, but they did not become widely
known until 1900. The laws provided the basis for the
science of genetics which advanced rapidly in the first
three decades of the twentieth century. During that
period geneticists were indifferent or hostile to
Darwinian selection. By the fourth decade, however,
a theoretical breakthrough had been achieved which
enabled R. A. Fisher (1930) and J. B. S. Haldane (1932)
to restate the doctrine of natural selection so as to
reconcile it with the principles of genetics. The result
has come to be known as the “synthetic theory” of
evolution which is now generally accepted (J. Huxley,
1943; B. Rensch, 1947; G. G. Simpson, 1949).
The new synthetic theory, like classical Darwinism,
undertakes to explain evolutionary changes in natural-
istic terms. But it avoids past oversimplifications by
correlating a number of causal factors to account for
those changes. Hence the theory admits phenomena
unrecognized by the Darwinians, such as different rates
and levels of evolution, different degrees of selection
pressure, evolution without speciation, etc. Further-
more, in the new theory the central feature of selection
is differential reproduction, not individual survival.
Hence the struggle for existence, the destruction of the
unfit, and the survival of the fit become special cases
of selection rather than identical with it. T. H. Huxley's
“gladiatorial theory of existence” can now be charac-
terized as a Victorian myth (Simpson, 1949).
The causal factors assembled by the synthetic theory
purport to explain pre-human biological evolution, but
they do not purport to explain what happened after
man emerged. For it is conceded that human evolution
has been powerfully influenced by cultural factors that
man himself has produced. Hence his history has been
quite unique among living things. Other animals have
been made by natural processes acting on them. Man
has very largely made himself by means of culture,
a new kind of adaptive mechanism. These facts were
systematically underlined by the rise of evolutionary
cultural anthropology in the nineteenth century. Works
such as Sir Henry Maine's
Ancient Law (1861), E. B.
Tylor's
Primitive Culture (1871), and Lewis Henry
Morgan's
Ancient Society (1877) laid some of the foun-
dations for a science of cultural evolution. After the
turn of the century, interest in this subject waned for
a time, but it has recently been revived by the writings
of L. A. White (1949), V. G. Childe (1936; 1951), and
J. H. Steward (1955). The subject contains many un-
solved problems, but evolutionary explanations appear
to provide one fruitful way of tackling them (see
Dobzhansky, 1962).
At the other end of the scale, evolutionary explana-
tions have been introduced into discussions of the ori-
gin of life. Innumerable accounts of how the first living
things came to be occurred in ancient religious tradi-
tions. But the subject eluded a scientific treatment, so
that Darwin could say as late as 1863, “it is mere
rubbish, thinking at present of the origin of life.” Nev-
ertheless, T. H. Huxley dealt with it in 1868, as did
John Tyndall in his Belfast address of 1874. With the
rise of twentieth-century biochemistry an evolutionary
approach to the subject became possible. A most influ-
ential hypothesis was stated by A. I. Oparin (1924;
trans. as The Origin of Life, New York, 1938) and by
Haldane (1929). According to a recent modified version
of this hypothesis, life originated by a process of chem-
ical evolution on the earth, before there was free oxy-
gen in its atmosphere. Through the action of ultraviolet
light, inorganic material gave rise to organic molecules,
which in turn evolved into complex biological
polymers having a primitive capacity to reproduce.
From these diffused polymers, specific closed organisms
developed, culminating in the nucleated cell. At this
stage chemical evolution was succeeded by organic
evolution (see Bernal, 1967).
This speculative reconstruction recognizes a sub-
stantial difference between chemical and organic evo-
lution. Yet the two processes are assumed to have some
formal elements in common. “One of these is the con-
cept of the survival of the fittest, of the maintenance
of one particular molecular pathway as against others
for which certain material substances proved to be
lacking” (Bernal, p. 30). It is supposed that random
combinations of inorganic elements were subject to a
kind of natural selection by which increasingly complex
and efficient aggregations were built up. Ultimately
one type of aggregation survived, and gave rise to
proto-life. Many unsolved problems remain in this area,
including that of explaining how the capacity for mo-
lecular replication or reproduction could have evolved.
Evolutionary conceptions figure in modern astron-
omy at two points. (1) There is a well-grounded theory
of stellar evolution which concerns the life-cycle of
main sequence stars. A developmental pattern has been
worked out that specifies a regular succession of phases
in a normal star's history. (2) There is also a group
of cosmological theories—relativistic descendants of
the cosmologies of Descartes, Kant, and Laplace—
which are based on evolutionary models. Here accounts
of the evolution of the nebulae from a primordial,
hyper-dense mass are proposed. These accounts are
based partly on mathematical deductions from obser-
vations and partly on purely hypothetical interpola-
tions that are not in conflict with observations. Yet as
in the case of the origin of life, cosmological evolution
is a subject containing many disputed issues.
The spread of evolutionary ideas in the sciences has
kept alive an interest in giving the ideas a metaphysical
generalization. This interest has been mainly mani-
fested, however, among workers in the life sciences
rather than among professional philosophers whose
anti-speculative predilections have been strong in re-
cent decades. Accordingly, generalized evolutionism
has tended to be lacking in philosophical finesse, and
has been little more than a semi-popular extension of
scientific material.
In various publications, Sir Julian Huxley has con-
tended that evolution encompasses “all the historical
processes of change and development at work in the
universe: in fact, it is the universe historically re-
garded” (1960, pp. 20-21). The overall process from
“cosmic star-dust to human society” is continuous, yet
it has three distinguishable phases which have super-
vened in the course of time: the cosmological, the
biological, and the psycho-social. Each of the phases
has its own self-transforming mechanisms, which dis-
play increasing efficiency, and so ensure genuine evo-
lutionary progress. Basically, what undergoes evolu-
tion, Huxley contends, is “the world stuff.” It is per
se neither mental nor material, but it has mental and
material aspects or “potentialities.” Prior to the
psycho-social phase, the universe was devoid of pur-
pose. With the appearance of homo sapiens, however,
purposes entered the cosmic scene. Human purposes
allow men to influence the course of evolution, if they
so decide, and hence man has become “the sole agent
of future evolutionary advance” (1953, p. 132).
A materialistic form of evolutionism is advocated by
Simpson (1949; 1964). He distinguishes (a) the nonevo-
lutionary dimension of the universe—the enduring
properties of matter-energy—from (b) the evolutionary
dimension—the temporally successive, cumulative
changes of configuration or structure that make up the
history of life. The properties in (a) constitute the
ultimate causal explanation of events, but historical
explanations do have a limited place in relation to (b).
Man is unique in being “the highest form of orga-
nization of matter and energy” (1949, p. 344). He is
the result of a purposeless, materialistic process. But
he does exhibit some behavior that is purposeful, and
that can be influenced by “an ethical need” within and
peculiar to himself. The need impels him to adopt
ethical standards for the guidance of his conduct in
society, but these standards are relative to changing
circumstances, and are never absolute. Simpson stresses
man's basic trait of “responsibility.” It is through the
exercise of this trait at the present critical point of
human affairs that homo sapiens can ensure either the
future welfare of the species or its early extinction.
As to whether mankind will face up to that respon-
sibility, Simpson finds no reason for despair, “but a
good deal of reason for pessimism.”
A more optimistic, religiously-oriented form of evo-
lutionism is presented in the posthumous writings of
the Jesuit paleoanthropologist, Teilhard de Chardin
(1955 ff.). Like Julian Huxley, he has espoused a
grandiose vision of cosmic evolution, or “cosmo-
genesis,” which is orthogenetic in the sense that it
depicts evolution as having been marked by a steady
increase in the complexity and concentration of the
stuff of the universe. This stuff has an external “material
face,” but inwardly it is psychical or spiritual. In its
evolution, successive thresholds of integration have
been passed, so that each later level is more intensely
concentrated or “involuted” than its predecessors. The
human level has added to the planet a new envelope,
the “noosphere,” which has been superimposed on the
biosphere. The concentration engendered by the
noosphere will make possible further human evolution.
Its outer manifestation will be the forming of a single
world-culture, and its inner state will be the melding
of individual consciousnesses in a Hyper-Personal
Consciousness “at a point which we might call
Omega.” Teilhard's concept of Point Omega is obscure,
like much else in his evolutionism. Apparently, Omega
is God, insofar as He determines the direction and
constitutes the goal of cosmic history. The melding of
personal consciousnesses at Omega will be achieved
by the power of love, which forms “le Milieu divin”
within which evolution takes place. All this represents
the expression of a mystical outlook having little con
cern with precise ideas or with the relation of what
is affirmed to any evidence.
It is plain that evolutionism is a family of concep-
tions having great vitality and viability. Its long, influ-
ential history is likely to be matched by its continuing
future impact on man's thinking about the world and
about himself.
