On the Origin of Species by Means of Natural Selection (thing)

The Theory

Since its introduction, the concept of evolution has been one of the most popular, yet most misunderstood themes of biology to the general public. Before the late 1850s, the most subscribed to idea of how life came to be as it is was divine creation. However, that would soon change.

The idea that life evolves was expressed by several eighteenth and nineteenth scientists. However, without a reasonable explanation for evolution, other scientists of the time opposed the idea vehemently. It wasn’t until 1859 that a naturalist from England, one Charles Darwin, provided convincing proof that species do evolve and suggested a means by which they do so.

To present his ideas, Darwin wrote a book in which he detailed his studies and observations and gave proof for the hypotheses he made. This rather technical book was called On the Origin of Species by Means of Natural Selection. This book, one of the most important books ever written, has directly impacted our civilization and sparked many new ideas and fields of science.

In the introduction to On the Origin of Species by Means of Natural Selection, Darwin had this to say, “The view that each species has been independently created—is erroneous. I am fully convinced that species are not immutable; but…are lineal descendants of some other and generally extinct species, in the same manner as the acknowledged varieties of any one species are the descendants of that species. Furthermore, I am convinced that Natural Selection has been the most important, but not the exclusive, means of modification.” Then, in the conclusion, he added, “Why, may it be asked, until recently did nearly all the most eminent living naturalists and geologists disbelieve in the mutability of species? It cannot be asserted that organic beings in a state of nature are subject to no variation; it cannot be proved that the amount of variation in the course of long ages is a limited quality; no clear distinction has been, or can be, drawn between species and well-marked varieties.” From these quotations, two of Darwin’s most profound axioms can be derived. First that species evolve through natural selection, and secondly, that species are not static in their design, but rather, can mutate. These two ideas are the staples that hold Darwin’s theory of evolution together.

This theory, the theory of evolution, has been modernized to included new discoveries made after the first printing of On the Origin of Species by Means of Natural Selection. However, those amendments were made to make the theory more complete, Darwin’s ideas are still the basis for the theory.

The theory is comprised of four major points. The first point is that variation is present within the genes of all species as the result of random mutations. The second point, commonly known as natural selection, states that in a given environment, some individuals of a species are better adapted for survival and therefore leave more offspring. The third point asserts that over time, change within a species leads to the replacement of old species by new species as less successful species become extinct. Fourthly and lastly, there is clear evidence from fossil and many other sources that the species now on Earth have descended from ancestral forms that are extinct. In a nutshell Darwin’s theory of evolution can be explained quite succinctly. Variation is the basis for all evolution; without it, species would truly be immutable. Thanks to variation, some individuals in a species are change very slightly. If these changes are bad for the individual, the individual will shortly die and not pass on the mutated gene, however, if the variation is advantageous to the individual, it is prone to better survive and have offspring that are also better prone to survive. This increased level of being prone eventually leads to a replacement of the not so prone to survive species by the individuals that are more prone. This can be seen in the fossil record of species that are now extinct.

It must be noted that Darwin did not develop all of his theories entirely by himself. While doing his field studies, Darwin read Charles Lyell’s Principles of Geology in which was detailed a theory of evolution by Jean Babtiste Lamarck. Lamarck’s theory was based on the concept of use and disuse. According to Lamarck, evolution occurs as structures develop through use, or disappear because of disuse, and that these “acquired characteristics” are passed on to offspring. Although now known to be wrong, this theory led Darwin to note how as he visited different places, there were things that could only be attributed to a process of gradual change or an evolution.

When he returned from his field studies, Darwin read an essay written by the English economist Thomas Malthus called Essay on the Principle of Population. In the essay, Malthus explained his principle of population: that the human population could cover the Earth’s entire surface within a very short period of time if it could reproduce unchecked, but would not due to death caused by disease, war, and famine.

Darwin, upon considering what Malthus had proposed, decided that Malthus’ principle of population applied to all species, not only humans. He determined that every organism had the potential to produce many offspring during its lifetime, but not all would survive. Those who would survive would do so for a reason. Here came Darwin’s most important conjecture: individuals that possess superior physical or behavioral attributes are more likely to survive than those that are not so well endowed.

The Reaction

Darwin’s contemporaries were very religious in nature. Their way of living was that of the Bible and anything opposing the facts that were written in the Bible were obviously great evils. Upon reading On the Origin of Species by Means of Natural Selection, the highly religious called Darwin a heretic, a dissident, and a schismatist. They were outraged that someone would tinker with one of the most basic truths in their religion: creation, the idea that all life was created by God and that it has not changed since he created it.

However, the enlightened few could not help but believe what Darwin had theorized; they could not ignore the evident. Ockham’s razor is a basic scientific idea that suggests that the simpler a theory is, the better. If two theories predict phenomena to the same accuracy, then the one which is simpler is the better one. Moreover, additional aspects of a theory which do not lend it more powerful predicting ability are unnecessary and should be stripped away. Those aware of Ockham’s razor would immediately believe Darwin’s view over those of the religious folk. The first theory, that an omni-powerful God created everything would seem too difficult and not easy to understand over the second theory, Darwin’s, where everything could be explained through reason and intellect rather than blind faith.

Darwin was a very wise man; he could foresee the controversy that his book would bring. To bring some of this controversy to rest, he included the this passage in the final page of On the Origin of Species by Means of Natural Selection, “…from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.

From the beginning Darwin was a creationist, and, despite the development of his theory, continued to be one. In the last passage Darwin clearly stated that God created one or a few very basic life forms and from those, all of the ones we have today evolved. He found this view more beautiful than that which he and most other people previously held (that God created everything and that it still is as he created it, without change). The idea that life has no limits and that life will continue to evolve into wonderful creations is indeed an amazing and awe-inspiring thought.

Relevance

If Darwin were a person of the twentieth century and released On the Origin of Species by Means of Natural Selection in our lifetimes, it would be difficult to tell what the reaction would be. Surely, there would be some criticism from the church and from various political parties. However, from the scientific community, Darwin would receive much praise. I would not find it surprising if Darwin were to receive the Nobel Prize for his contributions to science. Then again, I do not know under what category the prize would be given, since without him, there would be no genetics! By contributing the theory of evolution to the world he has changed it in ways unimaginable.

pealco's note: I wrote this for an extra credit assignment in high school biology.