Tuesday, June 16, 2009

Darwin's On the Origin of Species

On the Origin of Species (Oxford World’s Classics Edition)
Charles Darwin
Reviewed by Ben Picozzi

On the Origin of Species (fully titled On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life) is Charles Darwin’s seminal work on the evolution of species according to natural selection. Although The Origin was originally intended as a rushed abstract to a larger species book, he never took up the species book and instead The Origin became his definitive engagement with evolutionary theory.

The Origin is remarkably devoid of citations and other academic conventions. Darwin does cite other sources on occasion, but he references authors by name and experiment. On the rare occasions in which he does cite publications, he does not include page numbers. While this may have been a byproduct of the rushed nature of Darwin’s writing, the uncluttered nature of the text makes it easy to read without being bogged down by an endless series of accreditations. Likewise, Darwin retreats from the austere language of science in favor of a more accessible – but no less compelling – style. This approach is consistent with his portrayal of evolution and natural selection. From its’ opening paragraph, which recalls Darwin’s voyages aboard the Beagle, to its conclusion, which Darwin ends with a famous appeal to the ‘grandeur’ of human life, Darwin presents evolution as not just an abstract scientific theory but something which can be appreciated by anyone.

However, all of this does not mean that The Origin is not a serious scientific text. Darwin treats his argument with the attention to rigor and organization expected of a writer attempting to persuade an educated audience. Darwin is remarkably thorough in anticipating and addressing potential objections. On several occasions, I would posit a particular objection to the text, only for Darwin to address that objection in the very next paragraph! Furthermore, Darwin devotes an entire section to responding to ‘difficulties on the theory’ of natural selection in an effort to preempt his rivals. The section on ‘instinct’ is another defensive measure, written with a view to dismissing the possibility of instincts which stand outside of evolutionary processes.

Despite the attention which he pays to his opponents, Darwin also builds his own positive case for his evolutionary theory. Again, the structure of The Origin demonstrates Darwin’s understanding of argument in addition to science. He begins with the easily-grasped example of domestic selection, which he uses to prime his audience for the possibility that there is a similar process of ‘natural selection’ which occurs in non-domestic settings. He then motivates this possibility with a discussion of the conditions – namely, scarcity – which make a theory of natural selection plausible. He concludes with a discussion of independent evidence supporting such a theory.

Darwin’s theory of evolution by natural selection is not perfect. He does make some mistakes. Notably, his lack of an understanding of heredity, leads him to bizarre conclusions concerning instances of ‘atavism’ or ‘reversion’ in which offspring will exhibit the traits of ancestors several generations removed. Likewise, his focus on the ‘struggle’ of the macroscopic world is myopic with respect to the microscopic world of disease and parasitism now believed to be the primary driver of evolutionary change. Much of what he writes about species migration is written in ignorance of continental drift. These are just the obvious mistakes. The unobvious mistakes are still a matter of controversy. The debate between functionalism and formalism is still ongoing. If you believe Gould, Darwin’s focus on gradualism, which he inherited from geological theory, underdetermines the role that sudden changes in environment – Gould’s punctuated equilibria – play in producing evolutionary change. But for all that Darwin got wrong, he got many things right. The evidence he provides for evolution – morphology, embryology, vestigial organs, etc. – is the same evidence which is still taught in high school classrooms today. The persistence of Darwin’s original examples is a commendation of his capabilities as a scientific thinker. His discussion of taxonomy is similarly revolutionary.

It might be tempting given the increasingly-tedious debate between religion and science to try to read The Origin without attending to any rival religious theories. However, such an attempt would be futile. Much of Darwin’s aforementioned negative project of responding to objections addresses religious theories in some form. Notably, Darwin devotes an entire chapter of the book – the section on ‘difficulties’ – to refuting the objections of his opponents, which included the creationists of his day. Many of these objections, including the absence of transition species in the fossil record and the supposed ‘irreducible complexity’ of certain features, are the same arguments raised in contemporary debates. In fact, in the passage devoted to irreducible complexity, Darwin explicitly attacks the belief that such features require a ‘Creator’. ie. God. Likewise, his discussion of the ‘instincts’ is an attempt to naturalize the mind and deprive his religious opponents of a powerful argument against religion and for divine intervention.

That stated, religion does not have to be the reason why one chooses to read The Origin. Large sections of the text do not directly engage religious theories. Likewise, while the text has obvious scientific value, science alone should not be the justification. Modern biology textbooks, while inspired by Darwinian principles, offer a more accurate and concise theory of evolution. However, what The Origin apart from these pretenders is the historical-cultural context in which it was produced. Darwin’s book provides a unique insight into the Victorian world and the powerful argument which changed it.

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