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. 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.
- . 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).