Using Richard Dawkins’ theory of the selfish gene and the evolutionarily stable strategy (ESS) theory, we explain how the balance of eggs and non-eggs is a strategy that reflects the genetic selfishness of each individual while maintaining the stability of the ecosystem.
In his book The Selfish Gene, Richard Dawkins rejects the concept of species, which has been used by the scientific community and education system to refer to biological evolution, and looks at living systems from the perspective of genes. In the book, he cites the example of the cockatoo, which lays its eggs in the nests of other birds to increase the chances of genetic survival. By taking advantage of the fact that they do their best to produce genetically similar offspring, they are able to reproduce and preserve their genes without much effort.
According to Dawkins’ theory, due to the selfishness of genes, individuals are inclined to spread their genes as much as possible. But this raises a question. Obviously, from an objective point of view, the behavior of laying birds is much more beneficial to the survival of the species than that of non-laying birds. However, it is ironic that not all birds do this. Clearly, according to Dawkins’s theory, genetic selfishness should cause all birds to “lay eggs” because it is advantageous to their survival, but we only observe this phenomenon in some laying birds, and it does not spread to all birds en masse. This contradicts Dawkins’ theory of genetic selfishness. To explain this logically, let’s look at the evolutionarily stable strategy (ESS) theory mentioned in the book and see how it relates.
The ESS theory explains that once a strategy is adopted by most members of a population, no other strategy can overtake it. The idea is that individuals will accept and follow the strategy that the majority of individuals in the population are following because it is in their best interest to survive, rather than follow a different strategy. Let’s look at the ESS theory in a little more detail. Suppose there are two groups within a population with different temperaments. Let’s divide the population into fierce, assertive hawks and meek, pragmatic doves.
If the population is composed entirely of hawks, the population will suffer on average because all individuals will fight until they are badly injured. However, if a pigeon faction appears, the genetic equilibrium is disrupted because it is more beneficial to follow the pigeon faction’s strategy than the hawk faction’s strategy of fighting to the death and losing money. Conversely, if all the individuals in the population adopted the dove strategy, there would be no injuries due to fights between individuals. However, if an individual with a hawkish strategy is introduced into the population, it will be dominant among the doves and will have a huge advantage. This would naturally lead to an increase in the number of individuals following the hawkish strategy, which would also disrupt the equilibrium. Therefore, for the benefit of the population as a whole and for its stable survival, each individual does not simply exercise its genetic selfishness to favor one strategy or the other, but calculates the optimal environment to balance the number of individuals following each strategy. In the case of the hawks and doves mentioned above, the survival of the entire population is most favorable when there is a 5:7 ratio of hawks to doves, so most populations will follow this ratio. From this, we can see that the ESS strategy emerged and stabilized through the genetic selfishness of each individual.
In the book, ESS is only discussed as a phenomenon within a species, but extending it to cross-species problems can be a great clue to understanding the phenomenon of spawning, so I will apply ESS across species to explain the selection and behavior of not only spawning birds but also non-spawning birds.
First, let’s divide birds into egg-laying birds and non-laying birds. If all birds were non-laying birds, each individual would reproduce independently without much direct influence on the hatching of eggs and the reproduction of offspring. However, if an oviparous bird is introduced into the mix and starts laying eggs, the benefits to the bird are very large and its survival chances are improved, so the number of oviparous birds will increase. On the other hand, if all birds were to become egg-laying, all birds would lose out because they would not be able to lay eggs and reproduce because they do not build nests and raise their own eggs. In this situation, non-turbinate birds would have an advantage over turbinate birds because they can build nests and reproduce their own offspring. Therefore, there would be more non-turbinate birds, which are more likely to survive and reproduce.
The equilibrium between the two species is only stable when their strategies coexist. This is the result of behavioral patterns that originate from genetic heterogeneity, which have diverged into different strategies under the pressure of natural selection. For example, laying eggs in the nests of other birds is advantageous for laying birds, but if all birds were to lay eggs, the ecosystem would be disrupted. Non-egg laying birds, on the other hand, raise their own offspring, which can maintain the balance of the ecosystem by allowing the existence of egg laying birds.
Therefore, the genetic selfishness of each individual does not necessarily lead to spawning, but rather to the right balance between spawners and non-spawners according to the ESS. Initially, the problem with interspecific selfishness in egg-laying was that if egg-laying is genetically advantageous, then the behavior of non-laying birds cannot be interpreted in terms of genetic selfishness. However, by applying the ESS theory across species, it was found that the behavior of the non-laying bird also reflects the selfishness of the genes as it is favorable for the survival of the species.
Furthermore, the interaction between oviparous and non-oviparous birds shows how gene selfishness works not only within populations, but also between populations. This provides an important example of how Dawkins’ claim that genetic selfishness is not just a survival strategy at the individual level, but also drives evolution and adaptation in a broader ecological context.
From this perspective, Dawkins’ theory of the selfish gene provides a clear explanation of how genes seek to maximize their own survival and reproduction through the actions of individuals. At the same time, combined with ESS theory, it provides important insights into understanding the diversity of genetic strategies and the resulting ecological balance. This is essential for a deeper understanding of the complex evolutionary processes of life, and provides a useful framework for exploring various aspects of natural selection.
Taken together, Dawkins’ theory makes a significant contribution to explaining the behavior and evolution of life from the perspective of genes, and its explanatory power is further enhanced by its combination with ESS theory. This has important implications for biological research and education, and is an essential concept for understanding the complexity of life.
