Monkeys, dogmas and “Jenkin’s nightmare”

After various “monkey processes” in America, which “KT” wrote about several times, a similar show began in Russia. The article dedicated to this event by Kirill Yes’kov (“KT” #633), one of the best Russian popularizers of biology¹, makes the author of these lines want to share a few thoughts with readers. The first is related to the question of why exactly the theory of evolution becomes the target of attacks by dogmatists. A literal reading of sacred texts contradicts not only evolutionary doctrine but also the law of conservation of energy. For example, someone might decide that the miracle of Joshua stopping the sun proves the inadequacy of Newtonian physics. Yet, for some reason, it is evolutionary doctrine that is attacked. Partly this is explained by the arrogance of the “king of nature,” who does not want to be related to livestock. But even here attention is often directed away from what is needed. Thus, opponents of evolution say that they are offended by the idea of human origin from a monkey. Strictly speaking, from the point of view of evolutionary theory it is correct to speak of origin from common ancestors with modern monkeys, of kinship with other monkeys, of monkey‑like ancestors of humans. And to understand what a “monkey” is, let us look into reference works and see that, zoologically, a human did not simply “originate from a monkey,” he is a monkey. No system can be absolute, but on this issue there was a relative consensus of views for a long time. Since the 19th century, the order Primates has been divided into two suborders: Prosimii (half‑monkeys) and the higher primates (Anthropoidea²). The latter includes the broad‑nosed, narrow‑nosed, and anthropoid monkeys; the latter group also includes the family Hominidae, whose representatives are us (and, according to recent views, also chimpanzees, gorillas and orangutans). A little more: a zoologist has no doubt about our belonging to the kingdom Animalia, the superclass Tetrapoda. And that’s it—no calls to study alternative classifications in school or university that would examine not human connections with livestock but his relations with angels! Returning to the question we started with. Evolutionary doctrine contains something that attracts the attention of professional disputers and science deniers. One such feature is the identification of an entire science (evolutionary biology) with the name of its founder. Geometry is not identified with Euclid, botany not with Theophrastus, and genetics not with Mendel. Yet the fact that evolutionary doctrine is not identical to Darwinism has to be constantly proved. Darwinism is a theory of the second half of the nineteenth century. By the way, from the author’s point of view, the synthetic theory of evolution (STE) cannot be called modern, as Kirill Yes’kov does. STE appeared in the middle of the last century. Both classical Darwinism and STE contain remarkable ideas that have become the foundation of modern views, as well as serious shortcomings that hinder unconditional acceptance of either theory. In my opinion, the main vulnerability of STE lies in the illusion of its completeness. Some biologists (especially teachers of “Darwinism”) act as if all major questions have already been answered in their science. Such an assessment immediately gives their views a dogmatic character. Continuous re‑verification of established views is a characteristic feature of science. And this is quite natural. When one wants to be sure that a building is truly sturdy, it is regularly inspected with defect‑detecting equipment. For science to be a body of reliable³ knowledge, it must constantly be questioned. I hope the reader understands that this doubt is of a completely different nature than the dogmatic claims of “scientific creationists.” The solution to this problem, oddly enough, may lie in a broader illumination of the diversity of approaches within evolutionary biology. An example that can illustrate this was “gifted” by Kirill Yes’kov’s article. “… Darwin indeed made several mistakes. <…> The so‑called Jenkin’s nightmare⁴ (a simple question: why does a newly acquired beneficial trait not “dissolve” in subsequent generations?) was pursued by him to the end of his life. <…> The exhaustive solution of the paradox… Darwin held in his hands in the most literal sense of the word. This solution, based on the discreteness of the hereditary code, was written in black and white in the book of the founder of genetics, Mendel, which Darwin read (this is reliably known) – but he did not appreciate it at all…” Proponents of STE like to recall “Jenkin’s nightmare” as a problem solved within the synthesis of genetics and evolutionism. From my point of view, “Jenkin’s nightmare” remains unsolved even within STE, and this is one of the reasons preventing STE from being called a “modern theory.” To untangle this tangled issue, we must return to Victorian England. Eight years after the publication of Darwin’s main book, engineer Fleeming Jenkin (Fleeming Jenkin) published a review in the North British Review that, for some reason, is rarely quoted. It is usually rendered as follows: Suppose a red poppy appears in a field of white poppies. It is more noticeable to pollinators and will have an advantage over the white ones. But, alas, its offspring will be only pink, the second generation pale‑pink, and soon the new trait will disappear. Only the discovery of Mendel, who proved that poppy colour is determined by a discretely inherited gene, helped find a solution to this problem. Having made a certain effort⁵, I found Jenkin’s original text and discovered a completely different argument. “Let us suppose a white man is shipwrecked and ends up on an island inhabited by black people… Our hero will probably become king; he will kill a great many blacks in the struggle for existence; he will have a huge number of wives and children, while many of his subjects will live and die as bachelors. <…> In the first generation there will be several dozen clever young mulattoes, on average intellectually superior to the blacks. We may expect that the throne for several generations will be occupied by a more or less yellow king; but could anyone believe that the whole island will gradually acquire a white or even yellow population, or that the islanders will acquire the energy, bravery, ingenuity, perseverance, self‑control, endurance, by virtue of which our hero killed so many of their ancestors and sired so many children—that is, the qualities actually selected by the struggle for existence, if it can select anything?”⁶ It becomes clear why Jenkin’s passage is rarely quoted—it is an openly racist text⁷. However, for evaluating Jenkin’s argument it is not crucial that a trait such as racial superiority does not exist; the traits he discusses are mainly culturally inherited. The important point is different. These traits are not monogenic, and the discreteness of genetic inheritance does not explain how they can be transmitted across generations. STE supporters substitute Jenkin’s argument, explaining monogenic inheritance according to Mendel, while the discussion concerned a complex trait whose development depends on many factors. It is likely that the adaptability (life‑success) of individuals in evolutionarily advanced groups depends mainly not on traits coded by single genes, but on complex, multivariate factors: growth, strength, memory, cleverness, endurance, resistance to infections, etc. If this is so, “Jenkin’s nightmare” is insurmountable both in classical Darwinism and in STE. Naturally, a mutation that sharply reduces any quality (for example, making its bearer an idiot) will be easily eliminated by selection. But genius, which depends not only on many hereditary endowments but also on their fortunate combination, will “dilute” in further crosses⁸. A common assumption is that traits such as intelligence depend on many genes, each of which only slightly improves the overall result. Survival of the more intelligent, according to this logic, would lead to a gradual increase in the frequency of favorable alleles of each of these genes and, consequently, to a rise in the average level of intellect in the population. Unfortunately, it is not that simple. The assumption of independent selection on many genes has been refuted within STE itself. Let us consider a simple example. Assume that the adaptability of individuals depends on only one gene (call it A). There are two alleles occurring with equal frequency—call them A1 (“good”) and A2 (“bad”). With sufficient selection efficiency, after some time only carriers of allele A1 will remain in the population. Thus, today’s carriers of allele A2 will leave no descendants that inherit this trait. In population‑genetic terms, carriers of allele A2 constitute a genetic load of the population, because they will not pass the trait to future generations. Now suppose that survival is influenced by genes A, B, C, D, E, F, G, H, I, J, K and L. Each is represented by a “good” and a “bad” allele. With uniform distribution only one individual out of every 2¹² has the optimal combination of genes. To retain only favorable alleles, selection would have to eliminate the offspring of the overwhelming majority of individuals in the population. The genetic load would then be 1 – 1/2¹², meaning that virtually the entire population would be removed from evolutionary prospects. Note that most individuals have roughly similar fitness, as they carry a mix of favorable alleles of some genes and unfavorable alleles of others. Using simple formulas to estimate the speed of such evolution, we see that it would require astronomical time already with twelve pairs of alleles. In real evolution, many more genes affect organismal fitness, most of which are represented by many alleles! Thus, “Jenkin’s nightmare” returns from oblivion. Having led the reader into a dead end, the author must also propose a way out. This way is the epigenetic theory of evolution of Ivan Ivanovich Shmälgause and Conrad Hel Woodington, proposed by Moscow paleontologist Mikhail Alexandrovich Shishkin (mentioned, by the way, also in Kirill Yes’kov’s article). “KT” has already written about this theory, and now it should be noted that, according to it, not only hereditary factors but also the pathways of individual organismal development (ontogenetic trajectories) are discrete. The main type of selection operating in the world around us is selection for stable ontogeny, through which offspring can reproduce the successful properties of their predecessors. Heredity is not the cause but the consequence of such selection. Its result is precisely the concordance of a set of genes that ensure normal development. Stabilizing selection acts not only on genes but also on many other factors influencing individual development (for example, on various forms of inheritance not linked to DNA). Thus, not only genes (which are so numerous that their combined effect is non‑discrete) become discretized, but also possible ontogenetic trajectories. It does not matter how many genes contribute to the choice of one of several developmental variants (the whole genotype may influence this). If selection favors the outcome of development along one of these paths, over time that path will become the most stable and turn into a population norm. “Jenkin’s nightmare” is not a historical fact but one of the key problems of evolutionary biology, whose solution required more than a century of scientific effort. Darwin understood the importance of this problem, but to this day not all Darwinists have fully realized it. Thus, many contentious issues remain within evolutionary biology. Perhaps, in the face of “external danger” (the dumbing‑down of the broad public by pseudoscientific propaganda) these contradictions should be hidden? Unfortunately, the hero who defeats the dragon acquires the traits of the defeated, and science, having survived the clash with dogma, can itself become dogmatic. Let us rather argue with each other and hope that from our polemics a evolutionary theory will eventually grow that can be rightfully called modern.

¹ His "History of the Earth and Life on It," available online, is, in my opinion, an unsurpassed example of a popular science biology book. Back to text

² Why was the Latin name Antropoidea chosen for this suborder, and not Simii – "monkeys"? Back to text

³ Not true—absolute truth is unattainable, but rather reliable, trustworthy! Back to text

⁴ "KT" #633 mistakenly printed "Jenkins" Back to text

⁵ Probably, this journal is not available at all in the post-Soviet space, and the text of Jenkin's article is inaccessible. How enviable is the ease with which my former student, working in a provincial American university, obtained a microfiche of a rare source from the university library. Back to text

⁶ Jenkin F. The origin of species. Art. I. // North Brit. Rev. 1867, June. Vol. 46. P. 277‑318. Back to text

⁷ On the other hand, if Jenkin were truly interested in racial theory, he would not have considered the yellow race as a result of hybridization between the white and black races. Back to text

D. Shabanov. Monkeys, Dogmas and “Jenkin’s Nightmare” // Computerrra, Moscow, 2006. – No. 17 (637). – pp. 44‑46