NEO-DARWINISM

Neo-Darwinism, the dominant interpretation at present, attempts to operate within a strictly materialistic framework. Evolution is regarded as a gradual process that comes about through the interplay of two factors: random mutations (accidental changes of genetic material) and natural selection that enables some of these changes to take over on the basis of their adaptive and reproductive advantages. The dynamic of evolution is based on the struggle and competition within and between species for limited resources. Although this process is considered directionless, it is apparently responsible for bringing forth the successive forms of life from single cell organisms to human beings. This interpretation of evolution has its merits, but also has some flaws. It was widely accepted in the 20th century not because it explained everything perfectly, but because it accounted for the facts better than any alternative and because it fitted well with the prevailing ideology of materialism. The purpose of what follows is not an attempt to prove Neo-Darwinism wrong, but to show that it is incomplete, which is why it cannot provide plausible explanations for all the characteristics of evolution (e.g. the increase of complexity) and for all the paleontological and biological facts. Actually, almost every key term associated with this view: chance, natural selection, competition, and gradualism, raise some doubts, especially if taken dogmatically as it is often the case at present[1].

  • [1]. The phrase ‘survival of the fittest', which is also linked to this model is not considered, because, as biologist Waddington already pointed out a long time ago, it is just a tautology: the existing species have survived because they have been the fittest, and they are the fittest because they have survived.

Chance

The materialist view is that all the changes in living organisms from the original single cell to a great variety of species that have existed and exist nowadays are the result of accidental genetic mutations[2]. Sure enough, some mutations may be accidental, but the claim that all the mutations in all the organisms have been, seems improbable for several reasons.

The effects of random mutations are almost always harmful and incur a loss, not a gain of information and complexity. Only in extremely rare cases may they be harmless. As Denton points out, ‘the fact that the vast majority of all mutations which have some detectable influence on the functioning of the organism are deleterious suggests that each functional living system is indeed enormously constrained to adaptive changes along only a tiny fraction of all the possible evolutionary trajectories available to it' (1998, p.341).

Even if an advantageous mutation occurs, the chances of it spreading throughout the population are very small and the chances against are extremely large. Taking into account the number of mutations that should have taken place, it is highly improbable that they would randomly lead from a single cell organism to human beings. The above quoted biologist states that ‘...evidence for the doctrine of the spontaneity of mutation is hardly ever presented. Its truth is nearly always assumed' (ibid., p.286). Chance mutations acted on by natural selection could scarcely account for variations within species (microevolution) let alone for successive variations among them (macroevolution). A blind process on an erratic trial-and-error basis is not impossible, but is incredible. Laszlo concludes:

...A random process could not have produced the kind of order that we meet with in our experience; it could not even have produced the kind of chaos that surrounds us at times. The fact is that pure, unadulterated chance could not have existed in the universe even if it coexisted with strands of order. If a series of chance events had punctuated the developmental process, the things that would have emerged out of that process would have randomly diverged among themselves... Given a process that is subject to pure chance, even previously ordered things would each grow their own way... Evidently, mere chance did not dominate the evolutionary process: there must also have been a significant degree of binding and coordination. (1993, p.18)

 

A usual response by neo-Darwinists to these challenges to chance as an explanation for the evolutionary process is that given enough time, random mutations would eventually lead to the complex life forms that exist today. However, this does not hold water, especially if long periods of stagnation are taken into account. The rates of mutation necessary are staggering, even within billions of years, considering the cost involved in disposing of the predominant bad mutations. Also, for a good mutation to become fixed in a population, all those individuals which do not have the new trait must die. When these considerations are combined with the low rates of reproduction of many animals, there has hardly been enough time for the present species to have evolved. To quote Laszlo again, ‘it is highly unlikely that random processes could have constructed an evolutionary sequence of which even a basic element, such as a protein or a gene, is complex beyond human capacities'. (ibid., p.91)

 

Environmental changes - another reason that makes evolution by chance implausible is adaptation to environmental changes. A suitable habitat may become less suitable in a relatively short time, which may threaten the survival of some species. In order to carry on, they have to adapt to new conditions. But, if species changed only by random and gradual mutations, they could not adapt fast enough. Yet, many somehow have managed to do so, by producing numerous and complex mutations that were just right.

 

Specific mutations - chance may play a part in mutations, but there are many instances indicating that genetic mutations are not always random and that specific genomic changes can take place under certain con­ditions. For example, both plants and insects can mutate so as to decontaminate the chemicals that enter their environment and develop a resistance to toxic substances. Some experiments (carried out independently by John Cairns and Barry Hall) also show that bacteria seem to be able to mutate solely their defective genes. Purely random mutations could never be so specific.

 

Inter-species consistency (evolutionary convergence) - despite the staggering variety of organisms brought forth during the Cambrian period (about 500 million years ago), the species that now populate the Earth exhibit striking regularities both within and among themselves. Some highly specific anatomical features show remarkable consistency among species with very different evolutionary histories. For example, the wings of birds and bats have similarly positioned bones as the flippers of seals and the forelimbs of equally unrelated amphibians, reptiles and vertebrates. Diverse species also exhibit common orders with regard to the position of the heart and the nervous system: in endoskeletal species the nervous system is in the back and the heart in the front position, while in exoskeletal species these positions are reversed. Another example is the eye: its basic structure appears to have been invented independently by about forty unrelated species. Organisms faced with the same challenge repeatedly arrive at the same solutions. Even if chance is streamlined through natural selection, the convergence of many highly ‘creative' solutions beggars belief.

  • [2]. It may be worth mentioning that Darwin is not responsible for this but his followers, who are trying, as any other ideologists or religious people, to be more Darwinian that Darwin himself. He allegedly wrote: ‘I cannot, anyhow, be contented to view this wonderful universe, and especially the nature of man, and conclude that everything is the result of brute force. 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' (in Fontana, D. 2003. p.73).

Natural selection

Natural selection is also a problem. Although it can weed out the misfits, natural selection cannot make new things (selection means choosing a few from a greater number). It does not create features but merely selects those that provide a greater survival value, and by doing so only narrows the width of the evolutionary process. Although Neo-Darwinists usually claim that the growth in complexity is the result of adaptation to environment, the appearance of increasingly complex organisms cannot be predicted solely from the work of natural selection upon random mutations.

The classical Darwinian mechanism works mainly to adapt individuals to their existing niches; individual variations do not contribute significantly to the emergence of new, more complex species. Even more importantly, many simple organisms are equally or better adapted to environmental variations than complex ones. Only they can be found in extreme conditions. Some unicellular life forms are spread across different environments much more than complex organisms (with the exception of humans). Evolutionist Gould states that ‘...without question, these earliest and simplest cells, the bacteria and their allies, remain the most abundant, widespread, and successful of all living things' (1988, p.44). If only adaptation directs evolution, evolution should not have moved from one cell organisms. This reasoning can be pushed even further:

If mere survival is the sole desideratum, then it would seem that some rudimentary type of organism would be all that is needed. And there would seem no reason why even a rudimentary type of organism should appear, since it could not hope to rival in longevity the everlasting rocks - but unstable DNA? (Edmunds, 1997, p.159)

Natural selection also cannot adequately explain long term adaptive changes. Some changes have immense consequences, and yet they could not have had adaptive advantages when they happened. One example is bisexual reproduction that increases diversity at great cost. Laszlo points out that ‘such a mechanism, while offering an obvious long-term advantage (the more rapid spread of advantageous mutations) does involve an equally obvious short-term disadvantage (the reduced average number of descendants due to males failing to produce offspring)' (1993, p.169).

Finally, natural selection seems to be based on a circular argument (everything that survives is adaptive and therefore selected, and everything that is selected is adaptive and survives) so it cannot be refuted, which does not make good science. When natural selection is used to explain everything, even mutually contradictory adaptations (e.g. the indistinctive colours of some insects, as well as very distinctive colours of others), in fact, it does not explain much.

Competition

A popular science writer, Hazen, describes evolution in the following way:

Charles Darwin proposed that evolution occurs because of the constant struggle for survival. Many more individuals of most species are born than can possibly survive. In the brutal competition for limited resources, individuals with advantageous traits are more favoured to survive long enough to pass those traits on to offspring. (1997, p.197)

This scary way of interpreting the evolutionary process, using phrases such as ‘survival of the fittest', ‘struggle', ‘brutal competition' and so forth, is fairly typical. Such a view was already popular in Darwin's time, probably as a reaction to the idealisation and glorification of nature by the Romantic movement.[3] However, this outlook is biased. No doubt that struggle and competition exist, but cooperation and symbioses within a species and between species is at least equally important[4]. For example, in order to start creating multi-cell organisms, some single-cell organisms must give up their capacity to reproduce - which is a striking example of symbiotic cooperation leading to complexity, but is contrary to ‘selfish gene' (or similar) interpretations. Using loaded adjectives such as ‘brutal' even in connection to the predatory nature of certain species is misleading. Every organism must die, and the suffering of those individuals who are unfit or misfit would probably be longer and more brutal without predators.

More importantly, if competition is the only driving force (between species, as well as within a species), one would expect that super-bacteria, super-plants or super-animals would have developed well before the appearance of humans and have taken over the whole eco-system. Yet, a delicate balance in nature that allows development seems to be permanently preserved. In rare cases when a particular type of species starts to dominate to the extent that they prevent further evolution, they conspicuously get wiped out. Many researchers have argued, for example, that mammals and thus humans could not have evolved without the demise of the dinosaurs (presumably, this has not been the fate of humans, although they are now dominant, because evolution so far has continued within the species - a point taken on in the following chapters).

  • [3]. His contemporary, poet Tennyson, famously characterised nature as ‘red in tooth and claw'.
  • [4]. After a long battle, the scientific community nowadays looks more favourably upon the proposition of Lynn Margulis that the cooperation between organisms, rather than competition, is the chief agent of natural selection. In a consolatory fashion, she said that ‘Darwin's grand vision was not wrong, only incomplete'. The position here is that the same applies to some other tenets of Neo-Darwinism.

Gradualism

The Neo-Darwinian theory maintains that life has been subject to a process of gradual transformation that allowed it to move from simple forms to ever more complex ones in small steps. Early life consisted of tiny unicellular organisms living in water, and every other form, extant or extinct, is connected by an unbroken chain of intermediate species to these first ones. This is not exactly the picture that one would get from the available fossil evidence. If evolution had been gradational, there should be greater variations between fossil specimens reflecting every small step in the process. But, this does not seem to be the case. Although there are an abundance of fossils of fully formed species, there are few contenders for their transitional forms (hence the phrase ‘missing link'). For example, there are no traces of the evolutionary ancestors of the trilobites in the rock layers beneath where the trilobites are found. It seems that trilobites, with their sophisticated optical systems, appear in the geological record relatively suddenly. These occurrences cannot be fully accounted for by the incompleteness of available data. Mounting paleontological evidence suggests that ‘speciation' (the emergence of new species) is a rapid process. Species change in relatively swift bursts, without leisurely transition periods[5]. These episodes of fast speciation are separated by fairly long spans during which no significant alterations can be detected. In other words, species appear abruptly, often in entirely different forms, and remain substantially unchanged for millions of years - a condition of stasis at odds with Darwin's model of continuous change. Then, just as quickly they become extinct and are immediately followed by other very different species[6]. The fossil record demonstrates abundantly that each episode of extinction was followed by a period when new forms proliferated, filling the ecological niches emptied by the old. Not only individual species but entire genera make their appearance in relatively short time. One example is the so-called Cambrian explosion about half a billion years ago, the sudden emergence, in the span of a few million years, of a great variety of the bigger animals that now populate the earth. The rapid evolution of mammals between 60 and 65 million years ago is another instance of this recurrent phenomenon. It is significant that every new cycle is not made of species at the same level of complexity, but more advanced ones.

 

This does not refute the continuity of the evolutionary process and certainly does not imply that an external force directly interferes with it, as the creationists (or the proponents of ‘Intelligent Design') would like to believe[7]. Slow, continuous change (within species) may be the norm during periods of environmental stability, while rapid speciation may occur during periods of environmental stress. When the milieu changes and the existing niches disappear, some species die out. Then the ‘peripheral isolates' (species that live in relatively small numbers) invade the centres of dominance and take over as the new main species. Also there are some creative solutions. For example, a link between prokaryotes (cells without organelles) and eukaryotes (cells with organelles and other structures) has not been found. The difference between these single-cell species is striking, and yet there are no intermediate stages between them. There are many living samples of each, but none of the intermediate stages. One imaginative possibility, put forward by the biologist Margulis, is that eukaryotes could be the result of a symbiosis of two different prokaryote species.

 

However, even when the above hypotheses are taken into account, conventional Darwinian mechanisms do not seem sufficient to explain the stops and starts observed in the fossil record (why species appear so abruptly and why they persist so long without changing.). These punctuations are too radical to allow for Neo-Darwinian interpretation. The problem is not only to explain the sudden burst but also, as a science writer Richard Kerr puts it, ‘what would maintain the equilibrium... keeping the new species from evolving in spite of environmental vagaries' (1995, p.1421-1422).

 

Intriguingly, growing evidence suggests that extinctions follow relatively regular periodic patterns[8]. The statistical chance of these patterns being a random occurrence is very small. Some of them may have been caused by physical factors (e.g. slight variations in the Earth's orbit over long periods, leading to a climate change). Nevertheless, it is conspicuous that new, and as a rule, more complex life always follows relatively soon after.

 

All the above makes it hardly plausible that new species could have arisen gradually by purely accidental transformation from one species into another.

  • [5]. Although it had its precursors, so-called punctuationism or punctuated equilibrium brought these facts to wider attention in the 1970s. It caused quite a stir, especially among dogmatic Neo-Darwinists, for fear that it could be used as a weapon against the theory of evolution as a whole.
  • [6]. Of course, ‘immediately' only in geological terms. For instance, Denton writes that ‘the evolutionary pattern was one of millions of years of stasis interrupted by periods of no more than 100, 000 years of rapid and sudden change' (1998, p.297).
  • [7]. Punctuationism, strictly speaking, is not ‘saltationism' (radical changes from one generation to the next or discontinuous appearance of new species), so it does not contradict the theory of evolution. It only adds weight to the argument that the traditional Darwinian mechanisms may not be the only factors.
  • [8]. The figure of 2.5 million years seems significant in this respect. Paleobiologist Sepkoski also suggests 26 million years, but according to Muller and Rohde, a 62 million year pattern is even more striking.

The increase of complexity

It is difficult to explain why more and more complex organisms have steadily appeared throughout evolution if every life form is supposed to be a result of accidental changes in the genetic material. The second law of thermodynamics demands that in any closed system entropy increases. This means that energy tends to go towards equilibrium, disintegrating into simpler forms, rather than integrating into more complex ones. In other words, a system inevitably moves towards the state of maximum randomness and disorganisation. Life, of course, is not a closed system, so an increase in complexity does not violate the second law. Nevertheless, it seems strange that at every level there is a tendency in evolution to produce something new and more complex, going persistently against that law - from relatively simple and crude forms to complex and refined ones. Polanyi and Prosch comment:

another unsolved problem arises from the continuous quantitative increase in DNA chains from those of bacteria to those of man - from about twenty million DNA alternatives to about twelve billion. DNA does not behave naturally. It moves from a lower energetic level to the higher, because it moves towards a higher complexity, which cannot be explained by DNA itself. There is no chemical model available to explain this enormous growth or the chemical explanation for this fundamental fact of the system, just as we have no chemical explanation for the historical origin of DNA or for its capacity to produce media that apparently anticipate the continued development of the embryo. (1975, p.167)

Materialists sometimes argue that all life could develop from a hypothetical first cell, as all new life develops from a single fertilised cell. However, a cell can develop into a complex organism only because all of the parts and instructions are in the original cell produced from conception. For large scale evolution, mutation must on average add information. It has been already demonstrated many times with detailed probabilistic analysis that this is extremely unlikely (most classic textbook cases of mutations cited in favour of neo-Darwinian evolution are, in fact, losses of information). So, it is incongruent to conclude that random mutations on their own can account for an increase of complexity.

Redundancy (two or more solutions for the same problem found in many species, such as the development of the vulva in the nematode) is a further challenge for the traditional view. Denton writes:

...the greater the degree of redundancy, the greater the need for simultaneous mutation to effect evolutionary change and the more difficult it is to believe that evolutionary change could have been engineered without intelligent direction. (1998, p.339)

Even if it is accepted that gradual incremental steps may in some cases accidentally lead to more complex structures, they could not do so in all. A comparison can be made with horse-drawn carts and motor cars. Carts and cars have some similarities (e.g. four wheels) and the same purpose, but cars did not gradually evolve from carts. Throughout centuries, carts had been steadily improved. However, in order to make a car, a leap that required the development and addition of several completely new components at the same time was needed. Even the simplest functional motor requires a few parts non-existent in the most advanced carts. And if just one of these components were missing, the motor would be nothing more but extra weight that the cart would be better off without. Similarly, the survival of a new species is dependent on all the necessary mechanisms (in at least a rudimentary form) being present to begin with. The problem is that obviously one gene mutation is not enough for more complex adaptation. But, if just two mutations are required at the same time to produce at least a slight advantage, the chance that this will happen accidentally decreases dramatically. One example from Dawkins' book The Blind Watchmaker may be a case in point (1986, p.97-99). Weakly electric fish use electric fields to navigate in muddy waters. However, this remarkable ability is of no use unless the body of the fish is absolutely rigid. To make up for this, the fish has developed one long fin, so that the rest of the body can remain still. Even with this fin, the movement of the fish is rather slow, but this is compensated for by its ability to detect electric fields in water. So, the navigation system is useless without the fin, and the fin is maladaptive without the navigation system. Their appearance had to be synchronous, but they require very different sets of genetic mutations (not to mention that these mechanisms must also be controlled by an appropriate nervous system and brain). Sometimes many simultaneous mutations are necessary, which makes chance, as their main cause, improbable. Considering that the vast majority of mutations are lethal anyway, it stretches belief that numerous beneficial mutations  can occur at the same time accidentally.

This issue is even more striking in relation to macroevolution, the emergence of new (usually more complex) species from earlier ones, especially if it is taken into account that intermediary forms are often not found, and that no breeders have ever managed to produce one species from another. To quote Denton again:

There are innumerable examples of complex organs and adaptations which are not led up to by any known or even, in some cases, conceivable series of feasible intermediates. In the case, for example, of the flight feather of a bird, the amniotic egg, the bacterial flagellum, the avian lung, no convincing explanation of how they could have evolved gradually has ever been provided. (1998, p.275)

Let us take one of these examples. No transitional fossil structure between scale and feather is known. This is not surprising, considering that a half-feather is  likely to be a disadvantage rather than an advantage. A feather has a quite complicated structure that is light, and yet wind-resistant. This is possible because of the complex system of barbs and barbules. Barbules on one side of the barb are rigged, and on the other have hooks. It is hard to imagine that chance mutations could produce this precise cross-linking of the barbules to make a connecting lattice. Even if the chance mutation of a ridge/hook occurs in two of the barbules, it also needs to be translated to the rest of the structure. Moreover, if the lattice structure was not lubricated, the sliding joint made by the hooked and ridged barbules would soon fray, which means that the wings would be useless. Many others adaptations are necessary to have birds that can fly (forward-facing elbow joints, navigating tail, strong wing muscles, hollow bones etc.). Even if all of them have developed gradually, each step had to be synchronised and the new must be so great an advantage that it compensates for the losses (of fully functional forelimbs or strong bones). Moreover, not only does each modification have to have sufficient survival value, but the related genes also have to be dominant in order to pass it on to successive generations. Of course, once this transformation has occurred, natural selection will select the better wings from the less workable wings. Evolution clearly operates in part by Darwinian natural selection, but this process simply selects those transformations that have already occurred by different mechanisms.

The problem of complexity for undirected evolution resides not only in the remarkable number of components that are sometimes necessary, but also in the fact that life forms are such highly integrated systems that their components cannot be changed independently. Any functional change would require specific compensatory changes in the interacting subsystems. For instance, a change in a protein structure would necessitate many complex simultaneous changes throughout the molecule to preserve any biological function. Denton concludes that ‘it is hard to envisage a reality less amenable to Darwinian change via a series of independent undirected mutations altering one component of the organism at a time' (ibid. p.342).

The above does not imply that complexity is irreducible, as proponents of Intelligent Design would like to present. For example, some components may have been adapted from existing structures that had a different faction, or more significantly, irreducibility may diminish on a molecular level. However, it still makes sense to challenge the claim that such complexities can be fully explained by the adaptive selection of purely accidental mutations.

Concluding Remarks

The above issues are not detrimental to evolution as such, nor do they necessarily lead to a conclusion that species were created as separate units by an external agency. For instance, the genomes of all organisms are clustered in a relatively small region of DNA sequence space forming a tree of related sequences that can all be inter-converted via a series of tiny incremental steps. So the sharp discontinuities between different organs and different types of organisms greatly diminish at the DNA level. What looks very different on the macro level, may not be so different on the DNA level:

...in DNA sequence space it is possible to move at least hypothetically from one adaptation (position) to another in DNA space via functionless or meaningless intermediate sequences. This is because a DNA sequence does not have to be functional to survive and be passed on through the generations. In fact, the greater part of all the DNA in nearly all the cells in higher organisms, although it is copied faithfully at each cell division, is never expressed... It is very easy to imagine how an evolving DNA sequence might be passed silently down through several generations before being expressed... [this] means that new sequences and hence new evolutionary innovations can be generated, at least hypothetically, via functionless intermediates. Thus, new organs and structures that cannot be reached via a series of functional morphological intermediates can still be reached by change in DNA sequence space. (Denton, 1998, p.278-279)

Some genetic changes, especially in higher organisms, have been largely a matter of the rearrangement of pre-existing genes rather than the emergence of new ones. Information specifying the future of evolutionary events may be stored in so-called junk DNA (non-protein-coding DNA). Many such sequences have been conserved over millions of years of evolution. This, however, does not explain the enormous increase of the DNA chain throughout evolution, and even if it is assumed that these dormant genes are the key, the questions remains why they are passed over to the next generations when they are not needed, and even more importantly, why they become active just when they are. To repeat, these objections do not invalidate the idea of evolution as an organising principle, only its reductionist interpretation. The above arguments are an attempt to show that mechanisms that Neo-Darwinists use to explain the evolutionary process are not sufficient, strongly indicating directed evolution:

The sudden emergence of an entirely new type of organism, or of a functionally perfect novel organ system, would be almost impossible to account for except within some kind of directed evolutionary or teleological framework. (ibid., p.296)

If this is the case, it is reasonable to consider what is the minimum that such a framework would require.