Where is the purposelessness of evolution?

2012-03-23 08:54
We often hear talk of scientists claiming that evolution is a purposeless process. Some claim that purpose is an illusion because of evolution by natural selection. For example, Professor Larry Moran, a Professor in the Department of Biochemistry at the University of Toronto has this to say:

“One of the most astonishing discoveries of modern science is that the universe does not exhibit any signs of "purpose" or "goals." This single conclusion is probably more responsible for the profound conflict between science and religion than any other. The attractiveness of religion was that it seemed to answer the "why" questions that science, presumably, could not answer. Now, modern science tells us that the question was meaningless.”

He goes on to cite two other scientists, Douglas Futuyma and Richard Dawkins, who share the same views regarding purpose and evolution. Professor Moran also argues that this view comes naturally to many evolutionary biologists. This may very well be true for the majority of evolutionary biologists.

The question of whether there is purpose or not is of course not something that can be solved with empirical science. There is no experiment to test whether there is or isn’t purpose. Scientists do not qualitatively or quantitatively measure whether there is purpose. They don’t look through a microscope or use some other instrument and conclude that there is no evidence of purpose within a 99% interval of certainty. In other words, the question regarding whether there is or isn’t purpose is irrelevant to the empirical and real sciences. Professor Moran is right on this, the question of purpose is meaningless to empirical science. Empirical science does not deal with the question of purpose.

The question of purpose is for the logical and rational sciences. You guessed it, it is ultimately a metaphysical issue. Aristotle was one of the first to provide a full treatment of the concept of purpose. Later, scholars such as Aquinas built upon his ideas. For Aristotle, the purpose of something is identified with its natural ends or final causes. Teleology is the view that natural ends are natural phenomena and intrinsic to natural substances. Aristotelian teleology can be distilled to its simplest form as “every agent acts towards an end”.

I will use three simple examples to explain what this means. Firstly, an example of two electrons being repelled. Secondly, the role helicase proteins play in replication. Lastly, the example of gravity.

For electrons, simply put, the natural ends of electrons are;
1) The generation of an electric field.
2) The generation of an electrostatic potential.
3) The generation of a magnetic field.
4) The generation of a vector potential.

What happens with two interacting electrons is that each electron generates an electric field (among other natural ends). These fields interact and generate a force. This force results in the movement of the electrons away from each other. The electrons, interacting electric fields and forces all have natural ends. These include the generation of electric field, generation of force and generation of movement respectively.

Helicases are known to be ring-shaped (typically hexamers) motor proteins. DNA replication occurs at about 1000 base pairs per second. In the cell, DNA forms a double helix. However, during DNA replication in a cell helicases unwind DNA. They unwind DNA at about the same speed that DNA replication occurs. Watch this video (at around 2:00-2:30 mins) to visualize it. Helicase is the blue, round protein unwinding the DNA in red. Simply put, the natural end of helicase is to unwind DNA.

Gravity is a force that causes objects of mass to attract each other with a force proportional to their mass. Therefore, it simply follows that the natural end of gravity is to attract objects of mass with a force proportional to their mass. We may not know much about the mechanisms of gravity. There are various theories in loop quantum theory or M-theory etc. This however, does not take away what we know about gravity's natural ends.

Aristotelian teleology is a simple concept to grasp. Importantly, it should not be confused with Paley's or the IDers' "complexity" arguments for design. Richard Dawkins is an example of someone that mistakenly confuses Aristotelian teleology for Paley's views on design. In his books "River out of Eden", he writes:
"Notoriously, of course, the apparent purposefulness of living bodies has dominated the classic Argument from Design, invoked by theologians from Aquinas to William Paley to modern "scientific" creationists."

In his book, "The God Delusion" Dawkins also deals with Aquinas' teleological argument. Dawkins does not appear to be aware of the simple fact that the fifth way has NOTHING to do with Paley's watchmaker analogy or ID. Dawkins completely misses this and tears down a straw man. So to be sure, Aristotelian teleology and design arguments from complexity are very different and one should NOT be confused with thinking they are the same.

As it turns out, even Darwin was a teleologist. Darwin had good things to say about Aristotle. From Allan Gotthelf's article "Darwin on Aristotle": Darwin in a letter to William Ogle:
"Linnaeus and Cuvier have been my two gods, though in very different ways, but they were mere schoolboys to old Aristotle."


The reason why Darwin was a teleologist is associated with his view of natural selection. Darwin's idea of natural selection preserves elements of Aristotle's teleology. Professor Andre Ariew points out (in his article "Platonic and Aristotelian Roots of Teleological Arguments in Cosmology and Biology") that:

“How is natural selection a teleological "force"? I see remnants of two sorts of teleology operating in Darwin. The key to seeing both is within Darwin’s concept of natural selection which can be summed up as follows: as a result of individuals possessing different heritable abilities striving to survive and reproduce in local environments, comes an explanation for changes in trait composition of populations through time. Traits become prevalent in populations because they are useful to organisms in their struggle to survive. Aristotle's functional teleology is preserved through the idea that an item's existence can be explained in terms of its usefulness (Lennox 1993). What makes a trait useful is that it provides certain individuals an advantage over others in their own struggle to survive and reproduce. Secondly, the concept of individual striving to survive and reproduce plays the fundamental role in Darwin's explanation for the origins of organic diversity. The same concept reminds us of Aristotle's formal teleology – the striving for self-preservation.”

The natural ends of natural selection are just to "maximize reproductive success in particular environmental niches".  Alternatively, it "maintains” the prevalence of beneficial mutations. On the other hand, it "limits" or "favours" some variations over other variations. Natural selection may "steer" biological change toward the local maxima in the "fitness landscape". So it turns out even natural selection has a natural end if we accept that it is a real cause and force of evolution and not merely a descriptive term.

Professor John O. Reiss also notes that the fitness landscape metaphor has teleological implications. Implicit in the fitness landscape metaphor is the view that natural selection acts "as a force driving the population toward this improved future state". If evolution is anything close to the metaphor then the process is fundamentally teleological. The natural end of evolution, if the fitness landscape were not metaphorical, would then be improved future states.


Where then is the purposelessness of evolution? Perhaps it is associated with random variation. As it turns out, the random part in random variation is not really random when it comes to mutations. Professor Dan Graur writes in his article “Single-base Mutation” in Encyclopedia of Life Sciences that mutations do not occur randomly throughout the genome and the direction of mutation is not random. The only way variation is seen as random is that it is random in respect to the effect variation has on fitness.

The major problem with this is that the precise meaning of fitness has not been settled. There is still a major debate about what exactly fitness is supposed to mean (see this post for more on this issue).

John O. Reiss notes also make the following interesting remark:
“The rigor of this approach, however, is lessened because there is as yet no universally agreed upon measure of fitness; fitness is either defined metaphorically, or defined only relative to the particular model or system used. It is fair to say that due to this lack, there is still no real agreement on what exactly the process of natural selection is. This is clearly a problem.”

Without a proper definition of fitness, we can’t really say what natural selection is in the first place. Also, without a proper definition of fitness we can’t really make any sense of how variation can be random relative to fitness in the first place. Still, evolutionary biologists would like to see evolution as "random, purposeless variation acted on by blind, purposeless natural selection".


Yet, on a macro level, we observe the natural ends of organisms. Eating, breathing, mating etc. are all natural ends of living organisms. On a molecular level, the wonderful natural ends of molecular machines and even simple chemical reactions are all there. Moving to ever-smaller things we also see elementary particles acting for an end e.g. generation of fields, forces electrostatic potentials etc.

However, we are to believe that all these natural ends and evolution are apparently because of more basic processes that are essentially random, purposeless or without any natural ends. The question is where are these purposeless and random processes? Which gap do they fit in? What are these assertions based? They certainly are not based on any empirical science.

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