This blog post explores how epigenetics challenges Dawkins’ selfish gene theory. It examines the constraints on gene expression and the influence of environmental factors.
The book ‘Epigenetics’ presented concepts that could conflict with my existing views on genetics. Author Richard C. Francis introduces the theory of epigenetics through this work. Epigenetics is the concept that gene expression can be suppressed by an organism’s environment—such as famine or differences in maternal affection received from parents—and passed on to offspring. The author also emphasizes that epigenetics represents a new direction in science with potential applications in disease treatment. This presentation of genetics’ expanded role made epigenetics feel particularly fresh.
While reading this book, I encountered Richard Dawkins’ concept of the ‘survival machine’. Dawkins argues that humans are merely ‘survival machines’ designed to pass genes to future generations. According to his book The Selfish Gene, genes—as self-replicators in the primordial soup—use not only humans but all bacteria, viruses, plants, and animals as survival tools. Dawkins’ concept of gene selfishness is explained through game theory, represented by the hawk and dove factions, and the ESS (Evolutionarily Stable Strategy) concept. Game theory addresses conflict and cooperation situations arising when an individual’s decisions affect others’ interests, providing a method to construct and analyze strategic scenarios. Furthermore, ESS refers to the optimal strategy for maximizing success within a population, meaning a strategy adopted by the majority that cannot be replaced by any alternative strategy. According to these concepts, genes are described as playing a role in strategically passing themselves on to subsequent generations through game theory and ESS. This is the claim that genes do not pass on based on the survival and reproduction of the individual, but rather use the individual for their own purposes. This claim by Dawkins was somewhat shocking, and while deeply contemplating this concept, I came to think that epigenetics could serve as a counterexample to Dawkins’ selfish gene hypothesis.
The first reason I saw epigenetics as conflicting with the selfish gene theory is the restriction of gene expression. Epigenetics suggests that environmental influences can alter the degree of methylation of genes, thereby limiting the expression of specific genes. Methylation is currently one of the most common and extensively studied epigenetic mechanisms, referring to the phenomenon where a methyl group attaches to a gene, suppressing its expression. When a specific gene is methylated, it remains unexpressed within the cell lineage containing that gene. However, if genes possessed a selfish tendency, they would have already developed ways to counteract external factors that suppress their expression. These external factors include contact with other survival machines, climate change, and other environmental conditions. If genes selected strategies with high survival probabilities through extensive trial and error and simulations, the phenomenon of expression restriction would not occur. The possibility that genes can be modified, given that restricted expression positively or negatively impacts the survival probability of the survival machine, conflicts with Dawkins’ ‘survival machine’ theory. Therefore, epigenetics could serve as a counterexample to the selfish gene hypothesis, which posits that genes use individuals as survival machines.
The Dutch famine cohort case, in particular, can be cited as a counterexample to gene selfishness. Towards the end of World War II, the German military’s blockade of supply routes severely restricted the daily calorie intake of citizens in major Dutch cities. This famine affected not only the generation that experienced it but also the health of children in their mothers’ wombs at the time. Compared to the generation that did not experience the famine, they had approximately twice the rate of obesity and increased incidence of diseases such as hypertension and coronary artery disease. This study is cited as a powerful example of environmental factors influencing genes, serving as strong evidence for epigenetics. If genes had chosen the survival machine as their protective mechanism, they would have been designed to prevent changes that hinder the survival machine’s chances of survival. However, this case suggests that Dawkins’ claim may not apply universally.
Since the publication of The Selfish Gene, Dawkins’ arguments have faced significant criticism. As life sciences advance, new theories emerge and existing ones are revised. From an anthropological perspective, every human possesses inherent value and shapes their own future. Yet if all such efforts serve merely to ensure gene survival and species preservation, the value of human existence itself would be greatly diminished. Epigenetics demonstrates that genes can be altered by external factors, particularly in ways that may reduce the survival probability of the survival machine. Therefore, epigenetics presents the possibility of preventing humans from existing solely as survival machines for genes. In this sense, I believe epigenetics is an important discipline with new implications.
