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The legacy of Charles Darwin

Wednesday 30 December 2009

The legacy of Charles Darwin

Wednesday, 16 December 2009.
150 years since the publication of On the Origin of Species

Roy Farrar, from The Socialist (weekly paper of CWI England and Wales)

Charles Darwin’s theory of ’natural selection’ changed the way that we look at ourselves. It contradicted the idea of an outside ’intelligent designer’, so it met a reaction from the religious establishment that still exists in part today. Some schools, particularly in the US, are teaching evolution as ’one point of view’ alongside creationism - a literal interpretation of the Old Testament. However, Darwin’s 150-year-old ideas remain a vital and central part of any discussion about evolution.

Darwin’s insight broke through old certainties. Species are no longer seen as immutable; life has diversified by a process of the splitting of species; life today is just part of an enormously long history of origins, extinctions and diversification. Evolution will also continue. Organisms are reasonably well adapted to their environments, but adaptation seldom reaches perfection because environments vary continuously. Those best adapted to the transient environment survive to breed and pass their attributes to the next generations.

Writing to Friedrich Engels in 1860 about Darwin’s book On the Origin of Species, Karl Marx commented: "Although it is developed in the crude English style, this is the book which contains the basis in natural history for our view". A little later he wrote to German socialist Ferdinand Lassalle: "Darwin’s book is very important and serves me as a basis in natural science for the class struggle in history".

Leon Trotsky considered that Darwin’s findings were "the highest triumph of the dialectic in the whole field of organic matter", in revealing how a process of relatively small changes accumulate to produce qualitative change. The dialectical view is one of seeing processes rather than static things. On whatever scale, things are always subject to change. When On the Origin of Species was published, Engels commented: "all rigidity was dissolved, all fixity dissipated... the whole of nature shown as moving in eternal flux".

The detailed classification of plants and animals by early biologists formed the basis of our modern international schemes. They described how nature is arranged in a hierarchical way, that species fit in genera, genera in families, and so on. These patterns seen by biologists recognised the inter-relationship amongst life forms and already implied a branching and splitting of species. But others saw the patterns as a manifestation of God’s will, regarding classification as a way to read God’s mind - so natural history was considered a proper pursuit for even country parsons.

Growing evidence

Darwin grew up sharing the typical views of the privileged class that he was born into. He was in no sense an evolutionist when he set sail on the survey ship the Beagle, although he was deeply influenced by the work of the geologist Lyell and so aware that the Earth is very ancient. He was also acquainted with the ideas of the German embryologists, of the biologist Linnaeus, the unorthodox evolutionary views of the French naturalists, of Lamarck, and so on. This was the mix of ideas that the young Darwin pondered when he began to think seriously about nature.

The five-year voyage round the world in Beagle, coupled with his reading and studying after his return changed everything. The evidence from plant and animal life in South America, and in particular on the Galapagos Islands, prompted Darwin to admit the ’impossible’ - that species are not immutable. If species could change to the extent that Darwin had discovered then he had to accept that the reason South American fossilised animals were similar to modern forms was that they were connected by descent. Further, he concluded that there were patterns of common descent and that all life evolved from a common ancestor.

Darwin was prompted to conceive of a mechanism, an engine to drive evolutionary changes. This process he dubbed ’natural selection’; a self-organising of systems and matter on any scale, the process of the self-sifting of matter conditioned by its properties and environments. And further, this was not just a process of recycling, but a generator of novelty in our world. Darwin could not square the simple idea of evolution as a linear progression (as ape - human - angel) and observed the evidence in nature of the branching and splitting off of species, that is of diversification. He was the first to see evolution as a process of branching and divergence, hence the diagram appearing in Origin is one showing evolution as a bushy tree.

While recognising the importance of Darwin’s theories, Marxists were not uncritical. "I accept the theory of evolution of the Darwinian doctrine, but I regard Darwin’s method of proof (struggle for life, natural selection) only as a first, provisional, imperfect expression of a newly discovered fact." (Engels in a letter to Lavrov, 1875). Phrases such as the ’struggle for life’ might be applicable to flora and fauna, but Marx recognised that as an explanation of human society they bolstered the Malthusian fantasy that over-population was the motive force of political economy.

Marx and others noted Darwin’s politically conservative views which allowed the ’Social Darwinists’ to use such phrases in defence of capitalist exploitation. "Survival of the fittest" and "struggle for existence" were not at first used by Darwin but were later taken up by him as metaphors to describe his theory.

The Social Darwinists argued that social progress lay in the economic competition between the various Victorian factory owners, and that attempts at social reform to help the poor and the vulnerable were to be condemned as being against "nature’s intentions". Darwin meant in "the survival of the fittest" not the crude ’dog eat dog’ of capitalist society, of every individual pitted against another, but rather the way a species develops and survives by best adapting to its environment, coping with change and reproducing.

Why Marxists defend Darwinism

For Marxists, defending evolutionary thought is not just an academic question. It is part of the broader class struggle, of arming the working class against capitalist ideologies, distortions and falsifications. Opponents of evolutionary thought demand that we must answer everything, and that because there are gaps in our knowledge that this somehow ’proves’ that the theory is imperfect and so false. Dialectical materialists understand that, at any particular stage in history, there are questions that science is unable to answer. Human knowledge like everything else has a history, it develops all the time, and there are no fixed or absolute limits.

The material world goes through continual changes and our knowledge therefore changes and develops in turn. In the course of scientific investigation this or that detail may be incorrect, or inadequately explain processes, but we can clearly say that things can be explained without any resort to supernatural forces. The ’laws of nature’ revealed by scientific inquiry are not laws as we understand in the legal sense, but are the abstraction from, and the generalising of, our experience of the real relationships between things.

Engels explained: "It is precisely dialectics that constitutes the most important form of thinking for present day natural science, for it alone offers the analogue for and thereby the method of explaining the evolutionary processes occurring in nature, interconnections in general, and transitions from one field of investigation to another" (Dialectics of Nature).

Marx and Engels argued that capitalism is only one stage in the development of human society. They said that class society is not eternal but arose out of definite material conditions, evolving over time as a result of the pressure of the development of the productive forces, and that it will reach an end to its ’life’ and will be succeeded by a higher stage of society.

Fossils reveal their secrets

Darwin was not the first person to ponder change and development of life forms over time. His under-rated contemporary Alfred Russel Wallace had drawn virtually the same conclusions which helped prompt Darwin to publish his findings. Long before them, the ancient Greeks had found the fossils of sea creatures on mountains around the Mediterranean and accepted that those lands had formerly been covered by water. The Greek philosophers could conceive that humans had been preceded by other life forms.

The industrial activity of the capitalist era - particularly canal building - revealed definite patterns of rock layers. Older rocks lay under newer strata. Uninterrupted processes, similar to today, worked on those rocks to produce their shapes and forms. Hence, many millions of years must have passed to do so. By 1830, geologists had enough fossil evidence to suggest that simple organisms were to be found in the oldest rocks and there was an apparent progression to more complex forms as the rocks became more recent.

"After long reflection I cannot avoid the conviction that no innate tendency to progressive development exists," commented Darwin on ’apparent progression’, opposing the teleological view that saw evolution as having supposed goals.

Pioneering geologists such as Lyell and Hutton gave backing to the estimated age of the Earth, as able to support life, as at least the 300 million years postulated by Huxley and Darwin in 1869. The immensity of the "deep time" of the geologists provided a time scale in which the process of ’natural selection’ could be framed. The increasing evidence for the vast age of the Earth, which hinted at former worlds populated by strange and exotic life, opposed the biblical story of creation.

The earlier ’catastrophe’ theory of geology failed to advance understanding, as each new Earth created after each upheaval was claimed to be subject to completely different processes than any of the previous periods. In practice this led nowhere. "In order to proceed as a scientist, you assume that nature’s laws are invariant and you decide to exhaust the range of familiar causes before inventing any unknown mechanisms." (Gould, Time’s Arrow, Time’s Circle, 1987).

Engels said: "Lyell first brought sense into geology by substituting for the sudden revolutions due to the mood of the creator the gradual effects of a slow transformation of the earth... The defect of Lyell’s view - at least in its first form - lay in conceiving the forces at work on the earth as constant, both in quality and quantity ... the earth does not develop ... but merely changes in an inconsequent fortuitous manner." (Introduction to Dialectics of Nature).

These "defects" gave a platform for an obsession with ’gradualism’ in the political ideas of the Victorian era. Ideas, fully embraced by Darwin, led him and others, even today, to a very one-sided view of evolutionary processes. Modern palaeontologists Stephen Jay Gould and Niles Eldridge have put forward the theory of "punctuated equilibrium" in opposition to the bias of gradualism. "Punctuated equilibrium, as its essential statement, accepts the literal record of geologically abrupt appearance and subsequent stasis as a reality for most species, not an expression of true gradualism filtered through an imperfect fossil record" (Gould, Time’s Arrow, Time’s Circle, 1987).

The materialist origins of life

Any idea that organic substances, the chemical stuff of life, were mysteriously different in some way from ordinary, non-organic matter was dispelled when in 1828 organic compounds were made from non-organic materials in the laboratory. Darwin did not attempt to answer the question of how life first arose as he considered there was not sufficient evidence available to do so. But he expressed some thoughts on this matter in a letter to a friend in 1871: "It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present.

"But if (and oh what a big if) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, heat, electricity, etc, present, that a protein compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly devoured, or absorbed, which would not have been the case before living creatures were formed."

Years later the Soviet scientist Oparin and the British Marxists Haldane and Bernal took up this question of the origins of life by following the lines suggested by Engels.

"Engels showed that a consistent materialist philosophy can follow only a single path in the attempt to solve the problem of the origin of life. Life has neither arisen spontaneously nor has it existed eternally. It must have, therefore, resulted from a long evolution of matter, its origin being merely one step in the course of its historical development." (Origin of Life, 1935, Oparin)

The descent of humankind

Human evolution was only hinted at in Origin of Species, but in Descent of Man (1871), Darwin contended that we are descended from African apes. This was controversial at the time and argued over for 100 years, until the modern science of molecular biology proved Darwin right. Darwin underlined the material links between mammals and humankind. Engels explained that we had appeared as the result of definite material processes, but also emphasised our uniqueness as a social animal. That we are the only animal that, through labour, interacts with nature. That we consciously alter the natural world, and that this process of using labour also changes ourselves.

The nineteenth century idealist ’brain first’ view of human development was opposed by Engels. He argued that labour and social organisation are not the product of the brain, but the cause of the development of the hand and brain. In his 1876 essay The Part Played by Labour in the Transition from Ape to Man Engels explained how upright posture freed the hand for using tools, and that increased intelligence and speech came later. The finds of palaeontologists, such as Johanson and Mary Leakey, show that a fully upright gait clearly existed before brain development.

The very earliest stages of development remain unclear. With each new fossil discovery debates are reopened as to where each species should stand in relation to the others on the human evolutionary tree. But these remain the details; the main outline of our development stays the same.

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