Posted by Jeeves
Today is the 200th anniversary of Charles Darwin, author of the Origin of Species and The Descent of Man, and commonly ascribed as the father of evolutionary thought. Evolutionary ideas had been alluded to by several philosophers and early biologists including Darwin’s own grandfather Erasmus Darwin. A paper containing a similar theory of natural selection by a contemporary biologist Alfred Russell Wallace convinced him to publish his seminal work. But, the comprehensive nature of the argument accompanied by detailed observations meant that, despite the modest competition, the theory of evolution by natural selection laid out by Darwin in The Origin of Species has gone down as ‘the single best idea anyone has ever had’.
Charles Darwin born in 1809
The beauty of Darwin’s theory of evolution is the elemental simplicity that describes the seemingly infinite complexity of the history of life on earth. Over hundreds of millions of years life transformed from the simple combination of a protozoan and a bacterium into the whole cornucopia of life that inhabits almost every conceivable part of our planet today, via the existence of everything that ever lived, ever. Its genius is that all that can be explained by a simple process of selection of minute genetic differences which increase the survival chances of that gene in a world of scarce resources and fearsome competition. Over many generations the combination of many small changes and their impact on the survivability of the host and therefore its genes leads to the emergence of new traits, new behaviours and eventually new species.
As a scientific concept Darwinian evolution has received universal acceptance and has underpinned the whole study of evolutionary biology and is a unifying principle in the biological sciences, much like Newtonian laws of gravity underpin the physical sciences.
Darwin as the founder of evolutionary biology had the misfortune of knowing less than all subsequent evolutionary biologists. There remains much legitimate debate concerning the actual processes and patterns of evolution. But subsequent discoveries of molecular genetics and numerous examples from the fossil record have shown the emergence of new species, transitional forms between known species and animal groups all occurring in exactly the way and by the exact method Darwin described. Fifty years after the publication of Darwin’s theory (and in the year of his 100th anniversary) there was still considerable doubt as to its legitimacy. But, as concurrent theories such as Lamarckian inheritance have been debunked, a further 100 years later we can now say that the evidence is overwhelming and there is no conceivable scientific alternative.
Unfortunately this scientific acceptance of Darwin has not been matched by public acceptance. The original publication of Darwin’s theory caused a huge outcry from the contemporary scientific and religious establishment. As scientific knowledge of biology has progressed legitimate scientific criticism has faded away. But, Darwinian evolution is still the target of religious attacks based on ardent belief, flawed and evasive arguments and misrepresented or bad science.
Natural selection creates a perfectly comprehensible and effectively simple explanation for the whole evolution of life with no need for external intervention by supernatural forces, omnipotent creators and intelligent designers. Evolution’s implicit threat to religion is that it demystifies the apparent miracle of life to a process of random chance driven by ruthless selection often caused by acts of remarkable violence. Evolution does not disprove the existence of gods but it really demarcates their area of operation. This threat has inspired an ongoing campaign which has created the allure of controversy and debate where there is none, and prevented Darwin from gaining the universal acceptance that he should. In recent years this religious assault has tried to assume a quasi-scientific cover with the theory of intelligent design.
I commented earlier that their is no conceivable alternative theory to describe the complexity of life. Intelligent design fails due to its adherence to supernatural forces in the action between designer and designed (or should that be creator and created). Some ID advocates have said that the exclusion of ID from the scientific lexicon on this basis is evidence of some convoluted arrogance and sinister atheisitic scientism. It is actually as a result of scientific method requiring hypothesis, experimentation, reproduction and then acceptance. ID by definition has only one being capable of experimentation. However, there is no clear consensus around many of ID’s arguments and no unifying theory to describe its processes. Most ID argumentsare flawed and misrepresented criticisms of evolution and rather than explaining these alleged flaws with an alternative scientific explanation they use them as proof of a supernatural intervention.
Much of the evidence to support Evolution (but by no means all) comes from the fossil record. At the time of the publication of The Origin of Species that record was a fraction of the size it is today and corresponding theories of geology were similarly underdeveloped meaning it was very unclear how old it actually was. We now know that this fossil record covers hundreds of millions of years. This record is also not a complete record of all life on earth. Only a tiny fraction of living organisms will die in the exact conditions that will favour preservation as fossils and only a tiny fraction of them will be discovered. Hard structures like bones, teeth and claws lend themselves much better to fossilisation than less robust structures like scales, skin and feathers.
The fossil record has alwasy been used as the stick to beat evolution and in Darwin’s day these accusations were far more credible. This record is now far more expansive and exclusively supports that theory. The apparent sudden appearance of complex forms in the Cambrian era has been shown to have happened over 35 million years and the hard and bony creatures that evolved at that time are much more likely to fossilise than the soft bodied creatures that preceded them. We now see extensive evidenceof complex life in the Pre-Cambrian seas in the fossil record. It is rarer because it is inevitably older and deeper and made up of species not conducive to fossilisation but it is there.
An absence of transitional forms in the fossil record caused Darwin much soul searching in his own lifetime. Now the fossil record is littered with transitional forms between species. The evolution of horses has over thirty transitional formsto link modern Equus to its earlier mammalian ancestors. Indeed some arguments state that transitional forms are seen in the higher taxa but not in more primitive forms, it is unclear why the designer would have designed some species to evolve and others to remain stable. Fossils like Archaeopteryx and Tiktaalik are clear evidence of special emergence between great animal kingdom groups and proponents of design have had to resort to clumsy reclassification into one group or another or making accusations of elaborate hoaxes.
The continuation of this argument is that the fossil record shows species in a stable state for millions of years. This is an inevitable result of evolution by natural selection. Increased mortality driven by changing circumstances, and concurrent scarcity of resources and competition for them, is the prime driver to the emergence of new forms. If a species inhabits an environment to which it is well suited with little competition for resources it will propogate and survive. With more offspring there will be a greater impact on the fossil record. The fossils we find are much more likely to show evolutions winners.
ID advocates also point to so called ‘living fossils’ or organisms alive today which appear in the fossil record in an apparently identical form hundreds of millions of years ago. Whilst this clearly demonstrates ancestry in many cases the fossilised specimen is not the same species. These are merely two closely related species with a highly successful collection of genes wll adapted to their environments and robust enough to weather the ravages of geological time. The many species of Crocodiles today are not the same as the first species of Crocodylidae to appear in the fossil record 200 million years ago.
Advocates of intelligent design make their trade by misrepresentation of scientific method and avoidance of scientific fact. They state that they merely wish to debate the controversy where none exists and then try and use that as a controversy that needs to be debated. They see evolution as having to prove itself every step of the way, explain every anomoly, justify every feature observed in taxonomy (which it does surprisingly well) and offer only a devotional faith in an ethereal puppet master as an alternative. They ascribe design to every living organism and see no need to explain by what process it was designed or, for what purpose. Their view of the world is that it is too complicated to be understood and therefore god did it. Luckily 200 years ago someone was born who didn’t accept such an elementary view of life.
Happy birthday Charles, and thanks for the single best idea anyone has ever had.
Tags: Charles Darwin, fossil records, Intelligent Design, Origin of Species, religious establishmen, The Descent of Man, theory of evolution
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