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The Idea of Evolution Evolving: A Critical Look at Darwin
Science is continuously evolving, just as the idea of evolution evolved from previous thought and continues to evolve into more complex ideas in the present day. From the very onset of The Origin of Species it is evident that Charles Darwin’s ideas are consistently evolving:
“After five years’ work I allowed myself to speculate on the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions, which then seemed to me probable: from that period to the present day I have steadily pursued the same object… My work is now nearly finished; but as it will take me two or three more years to complete it, and as my health is far from strong, I have been urged to publish this Abstract.” (p. 3)*
This formulating and re-formulating of ideas contributed to Darwin’s idea of the scientific method. He believed that there was a certain method or methodology to approaching the natural world and all other scientific pursuits.
Darwin acknowledged that the idea of evolution was not new. His grandfather, Erasmus Darwin, actually speculated on the idea. This can be seen in one of his many poems about nature:
Organic life beneath the shoreless waves
Was born and nurs’d in ocean’s pearly caves;
First forms minute, unseen by spheric glass,
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Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.
-Erasmus Darwin, 1802
Early thought on evolution can be traced back even farther to Buffon. He believed that species’ forms were fixed. Other early thinkers include Carl Von Linnaeus, a botanist, zoologist, and taxonomist, Jean Baptiste Lamarck, a naturalist, and Georges Cuiver. Lamarck’s theory, Lamarckianism, was the idea that characteristics acquired during an organism’s lifetime could be passed on to its progeny. Darwin rejected this idea in formulating his idea of natural selection. Georges Cuiver was the first scientist to recognize the significance of fossils and the idea of extinction. The idea of extinction was revolutionary at the time because most organized religions believed that species were perfectly created. It was impossible for them to understand the concept of perfectly created species dying out. Darwin understood this idea and expanded upon it theorizing that less adapted organisms will decrease in number until finally they no longer exist.
Darwin’s contemporaries greatly influenced him. His principle influence was Charles Lyell. His book Principles of Geology went around the world with Darwin on the HMS Beagle. Lyell developed the idea of uniformitarianiam. He believed that the earth and its features were shaped by everyday activities, such as, erosion and sedimentation.
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Darwin’s thought was greatly affected by this idea of uniform change. He could easily observe that the world was in constant flux. This continuous change is the driving factor in evolution. Darwin observed organisms adapting to their environment and evolving. Another contemporary that influenced Darwin was Thomas Malthus, a political economist who wrote An Essay on the Principle of Population. Here is an application Darwin makes on his ideas:
“In the next chapter the Struggle for Existence amongst all organic beings throughout the world, which inevitably follows from the high geometrical ratio of their increase, will be treated of. This is the doctrine of Malthus, applied to the whole animal and vegetable kingdoms. As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected.” (p.5-6)
This passage explicitly shows how Darwin can take an idea from another great thinker of his time, in this case, Malthus, and apply it to his theory of natural selection and ultimately the evolution of species as it enables it to survive. Darwin played off of many ideas other writers formulated.
From the cumulative effect of the ideas of his contemporaries and many of his own speculations, Darwin developed his theory of evolution of species by the process of natural selection. Below is a summary of his main points:
(1) Variation exists within any given population.
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(2) Individuals produce more offspring than can possibly survive.
(3) The environment will act as a selecting force allowing those individuals who are best adapted to survive and reproduce. While less adapted creatures will die out or decrease in numbers.
(4) Accumulated variations can cause divergence of species.
(5) These variations can be passed from one generation to the next.
(6) Sexual selection causes variations between one sex and the other.
Darwin’s first four principles can be easily verified by observing the natural world. The variations Darwin referred to in the 5th principle I listed was his weakest point at the time. Unbeknownst to him, Gregor Mendel had researched the means of inheritance. He was able to specify further the way in which traits were passed through successive generations. Mendel’s work, though ignored at the time, has become a turning point in the evolution of science. The means, he called factors at the time. They have now are more commonly referred to as chromosomes. These ideas were developed even further with the discovery of DNA and cellular genetics. Means of inheritance are now highly specified and the most easily verified of Darwin’s points. Scientists now know about sex-linked traits, anueploidy, trisomy, monosomy, and other chromosome abnormalities such as XYY syndrome. Genes can be mapped out and the process of inheritance is much more clearly understood. I am only giving a few examples here because genetics has developed into a very expansive field of science that is still growing present day. With new companies such as Celera Genomics, scientists are pushing the world into a biotech
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century where fears are arising that one day we will actually be able to genetically engineer our children.
Just as Darwin discredited some of his contemporary’s theories, some of his ideas have been discredited as well. Main ideas of controversy were Darwin’s ideas about gender and race. In his view, women were almost a sub-species to man. We know that this is simply absurd. Women and men have more in common than different, as do different races of people. The development of genetics has shed some light on the issue. All humans share 99.9% of the same genes. Where the differences arise is very slight. Science evolves continually.
The idea of evolution evolving can be clearly seen by looking at the work of great thinkers past, present, and future. Darwin’s specific concept of information gathering, speculation, and formulation of theories can be easily understood in the light of scientific discovery. Darwin knew that he didn’t see the whole picture of the natural world, but his insights have given future scientists whole new worlds to discover and speculate upon.
18 September 2003
My commentary on Darwinianism and his theory of Evol-lution…