#3 Modified Traits

Darwin founded his Theory of Descent with Modification through Natural Selection by likening Natural Selection to artificial selection by Man of domesticated animals. 

Artificial selection

Charles Darwin knew a lot about artificial selection from his pigeon fancying hobby –which was more of a home-based experiment than a simple hobby.  Man has produced many varieties of domesticated animals and cultivated plants, often with quite stunning traits.  In Chapter 1 of The Origin of Species Darwin describes artificial selection as nature providing variations in traits and Man adding them up in certain directions useful to him to produce an accumulative selection.  The importance consists in the great effect produced by the accumulation in one direction, during successive generations of slight differences (Origin, page 38).

The domestic breeds of pigeon – pouters, fantails, runts, barbs, dragons, carriers and tumblers are all descended from one wild species –the rock pigeon.  Darwin thought that the different breeds differed so extraordinarily in length and form of beak that they would have been ranked as distinct genera had they been found in the wild.

The breeder of domesticated animals produces the desired trait over many generations of breeding by selecting offspring that carry the desired trait to some degree and allowing these favoured individuals to survive and breed, while disposing of the remaining offspring.


In the wild, in order to survive, organisms must be adapted to their environment.  Darwin showed by careful analysis of many facts that natural populations have many variations in physical traits and individuals carrying advantageous traits that afford them greater adaptation survive and leave more offspring than less adapted individuals.  Darwin theorized that the continuing natural selection of slight variations in traits carried by individuals brings about the modification of these traits, and the continuing process leads to speciation.

Species and varieties

In the first two chapters of The Origin of Species Darwin discusses the difficulties that naturalists had of deciding whether closely related forms were distinct species or varieties of the same species.  He shows that each naturalist made a different classification with some naturalists ranking forms as distinct species and others ranking the same forms as varieties or geographical races of the same species.

Darwin concluded that no clear line of demarcation can be drawn between species and sub-species.  Species can be thought of as strongly marked and permanent varieties (Origin page 59).  This leads to the conclusion that species could not have been separately created.


Darwin supports this conclusion by information on hybridism.  The degrees of fertility between plants and animals of different varieties, species and genera do not show a definite demarcation.

From the amassing of observations Darwin concludes that allied species are co-descendants from common stocks; species belonging to a genus are descended from one species that has been modified through Natural Selection.  He writes that the view that most naturalists at the time entertained and which he formerly entertained – that each species has been independently created – is erroneous.

 “I am fully convinced that species are not immutable; but that those belonging to what are called the same genera 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.”  (Origin page 15).

Later in The Origin of Species Darwin expands this view of common descent to families and orders, and finally to class level. 

To summarize, Darwin defined Natural Selection as the preservation of favourable variations and the rejection of injurious variations.  Darwin established his Theory of Common Descent mainly to class level.  Thus, Natural Selection would bring about the modification of structures and other traits such that all the species belonging to one class would have evolved from a common ancestor.  (Common descent at class level will be discussed further in Chapter 6).

The modification of traits is the first strand of evolutionary thought in The Origin of Species.

#2 Evolutionary Thought

During the 17th and 18th century classification of the natural world led to the observation that species of plants and animals are found as variations on common themes.  It is this observation that impressed many naturalists and in the 19th century led Charles Darwin to seek an explanation.

A general belief in direct creation by God prevailed in Christian Europe at this time. But by the 19th century, naturalists generally believed in the continuous special creation of each species of plant and animal, while varieties belonging to species were believed to be produced by secondary causes.  The secondary causes included the artificial breeding of animals and cultivation of plants by Man to produce a great diversity of varieties.  It was known that extinctions had occurred in past geological eras and that ancient forms of life found as fossils are no longer found living today.  It was thought by many that God replenished the Earth with the creation of new species after extinctions had occurred; there was a general belief in Progressive Creationism.

Over the course of the famous five year voyage around the world as naturalist on board HMS Beagle between 1831 and 1836, Charles Darwin became convinced that species are not fixed.  Many years later, after much work on barnacles, beetles, orchids and all manner of other natural things including a hobby in pigeon fancying, Darwin wrote On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life published in 1859.

In The Origin of Species Darwin argued against the doctrine of the creation of each separate species.  Belief in the design of each species of plant and animal by God was known as the fixity, immutability or permanence of species. 

There had already been some attempts at an evolutionary understanding of the world, the most famous of which was proposed by the French naturalist Chevalier de Lamarck in Zoological Philosophy (1809).  Lamarck’s evolutionary ideas were quickly rejected, although the term ‘biology’, which he coined, became widely used.  Darwin’s own grandfather, Erasmus Darwin (1731-1802) also held evolutionary views.  Erasmus Darwin was a free thinker and political radical, who founded a philosophical society in Derby.  He had an unusual talent for writing scientific treatises in rhyming verse.  Erasmus Darwin wrote Zoonomia or the Laws of Organic Life in 1794-1796 in which he expressed the notion that species modify themselves by adapting to their environment with purpose residing in the desires of the animal itself.  Lamarckism was similar to this view.

Vestiges of the Natural History of Creation (1844) published anonymously by the Scottish autodidact and publisher Robert Chambers also had some influence at the time.  The case for evolution in Vestiges rested upon the observation that fossils found from the most ancient to the most recent geological strata demonstrate a gradual ‘ascent’.  It was proposed that new species could arise by sudden mutations in the course of reproduction.  These ‘hopeful monsters’ met with much ridicule from other naturalists and professors such as Adam Sedgwick.  However, Sedgwick argued against Vestiges on the grounds of theology, rather than science.  (The geological collection of Adam Sedgwick is kept at Cambridge University and is open to the public).

Evolution was ‘in the air’, especially among families with progressive ideas such as the Darwins, but Charles Darwin went much further.  He hit upon a new idea and followed it up with detailed scientific arguments.  Darwin proposed what he described as a principle of evolution and laws of variation in organic beings; he named the principle Natural Selection.  Natural Selection, as conceived by Darwin, is a natural process which is not guided towards any defined purpose or preconceived goal.  Even so, Darwin believed that the principle would have been set up by God in the beginning with the creation of the first forms of life. 

In how Natural Selection stands in relation to the Creator, Charles Darwin suggests that the Creator created the laws of science.  Darwin states emphatically in letters such as in a letter written to Asa Gray dated 22nd May 1860, that he never had the intention to write “atheistically” (Francis Darwin 2000, page 249).  Darwin writes in this letter, “I am inclined to look at everything as resulting from designed laws, with the details, whether good or bad, left to the working out of what we may call chance.”  Further down Darwin concludes, “I can see no reason why a man, or other animal, may not have been aboriginally produced by other laws, and that all these laws may have been expressly designed by an omniscient Creator, who foresaw every future event and consequence.”

Within Darwin’s concept of Natural Selection described in The Origin of Species there are three main strands of evolutionary thought.  I will explore the three strands of evolutionary thought under the subtitles Modified traits, Highly perfected organs and Replacement of less-improved forms.

#1 Natural Selection: Strands of Evolutionary Thought

The Theory of Entropic Evolution includes the concept of Natural Selection.  But what is this concept?  In fact, as Charles Darwin presented it, the concept of Natural Selection is more than one single concept – it is a concept composed of several strands of thought.  The objective of this chapter is to untie those strands and examine them.

The Origin of Species is one of my favourite books and very enjoyable to read.  I first read it when I was at University studying biology (in my first year) and its influence has stayed with me ever since.  Although I do not reach the same conclusions as Darwin, I have always felt complete oneness with his thought processes and the mode of his reasoning.

Due to the importance of Natural Selection and associated concepts for the Theory of Nanocreation and Entropic Evolution, I am going to give a detailed description and analysis of the ideas contained in The Origin of Species in this chapter / series of posts.

I will also take this opportunity to discuss the relationship between belief in Evolution and faith, and types of Creationism.