In this blog post, we will examine whether animal cooperative behavior is instinctive or a survival strategy designed by genes.
Darwin presented the revolutionary theory of evolution to the academic world in his book On the Origin of Species. Since then, numerous scholars have studied evolutionary theory and expanded upon it through various experiments and theoretical discussions. As a result, evolutionary theory has gone beyond a simple biological hypothesis to become a core theory of modern life science. Among them, Richard Dawkins is one of the evolutionary theorists who gained both popular and academic attention with his book The Selfish Gene, published in 1976. Dawkins advocated “gene selection theory” and attempted to explain biological phenomena at the genetic level.
He argues that various behaviors that appear to be “cooperative” or “altruistic” in the natural world are actually strategic products of the survival and replication of genes, or self-replication. In other words, behaviors that appear to pursue the interests of individuals or groups are actually the result of selection at the genetic level.
On the other hand, scholars such as Stephen Jay Gould argue through “multi-level selection theory” that natural selection does not necessarily occur only at the genetic level, but that selection can also occur at the individual or group level. They often refer to multi-level selection theory to explain altruistic behavior. For example, female lions hunting in packs and sharing their prey is clearly altruistic behavior. In that individuals share their resources with other individuals, this behavior appears to be for the benefit of the group as a whole. However, Dawkins explains this from the perspective of gene selection theory. Hunting in packs is a strategy that allows individuals to secure more prey than when hunting alone, and as a result, individuals obtain more resources, increasing the likelihood that their genes will be passed on to the next generation.
Dawkins also uses the example of worker bees to explain gene-centered evolution. Worker bees are sterile and cannot pass on their genes directly to their offspring. Nevertheless, worker bees work for the queen bee and even sacrifice their lives. At first glance, this may seem irrational from a genetic point of view. However, based on the genetic structure and kinship of worker bees, Dawkins sees this behavior as an indirect strategy to help spread their genes. In other words, by helping genetically close individuals (the queen bee and sister worker bees) survive and reproduce, they increase the likelihood that their genes will be passed on to future generations. In short, Dawkins’ core argument is that individuals are nothing more than “survival machines” designed by their genes to replicate and spread themselves.
Meanwhile, The Suicide of the Migratory Mouse (Song Ji-hyun, 2012) explains the breeding habits of migratory mice as an example of multilevel selection theory. According to this book, when selfish individuals and altruistic individuals reproduce separately, and then at a certain point in time, they mix again to form a new group, and this process is repeated, the number of altruistic individuals tends to increase over generations. This phenomenon cannot be explained simply by selection at the individual level, suggesting the possibility of selection intervention at the group level. Furthermore, using ants as an example, it is mentioned that only about 20% of the total population are strong and diligent in searching for food, etc., and behave efficiently for the group. This point is pointed out as something that cannot be fully explained by Dawkins’ gene-centered theory alone.
However, Dawkins did not recognize individual selection as the main unit of evolution from the outset. Rather, he repeatedly emphasized that individuals are merely a means for genes to spread. Therefore, it can be criticized that the scholars of the Gould camp place excessive significance on the altruistic behavior of individuals or groups, which is a human-centered interpretation.
The above passage argues that “what can be explained by multilevel selection theory can also be explained by gene selection theory, so it is wrong to think that only gene selection theory is correct,” criticizing Dawkins’ side for using Occam’s razor to justify their theory. However, this argument can be considered a somewhat distorted interpretation. Occam’s razor is originally a philosophical principle that states, “When two theories explain the same result, choose the simpler one.” It is not a tool for determining which theory is necessarily correct. The Dawkins camp takes the position that gene selection theory is mathematically equivalent to multilevel selection theory, but in certain situations, it is simpler and easier to understand when explained at the gene level. In other words, they prefer gene selection theory for the sake of simplicity, but do not conclude that multilevel selection theory is “wrong.”
It is also problematic to mention that there can be various answers using the example of the number card “▢▢▢=5.” Both 1+4 and 5×1 can be correct answers, but if the intention of the questioner is not clearly understood, the simple result alone cannot be considered the correct interpretation. However, it is not appropriate to use this analogy to criticize Dawkins’ theory. Dawkins never claimed that a particular interpretation is absolutely correct. Rather, he merely emphasized that, while acknowledging the possibility of multiple interpretations, a gene-centered explanation is more explanatory and predictable.
Ultimately, even if we look at the case of sterile worker bees again, although it may seem like a trait that is disadvantageous for the survival and reproduction of individuals, at the genetic level, it may actually result in the trait becoming more widespread. The same is true in ant societies. Even if a certain behavior that increases the efficiency of the entire group is disadvantageous for individuals, it can be advantageous at the genetic level.
The multilevel selection theory advocated by the Gould camp, especially the anti-adaptationist view, often tends to project human emotions onto animal behavior. When explaining altruistic behavior, interpreting it as if animals show compassion like humans is more of an emotional interpretation than a scientific explanation. Evolution is not a purposeful act but an accumulation of results, and interpreting the behavior of living things in terms of human morality or emotions is merely anthropocentric thinking.
Therefore, it is more convincing to view gene selection theory, rather than multilevel selection theory, as a theory that can explain the evolution and behavior of living organisms more generally. Gene selection theory not only explains the survival strategies of genes, but also has explanatory power that can be widely applied to various biological phenomena, and is a very effective tool for elucidating how the behavior of individuals contributes to the survival and replication strategies of genes.
