Scientific paradigm shifts are driven by new discoveries and controversies that challenge conventional thinking, as was the case with the 16th-century Copernicanism and 18th-century creationism. The case of Galilei and Darwin illustrates the difficulty of turning long-held beliefs into scientific fact, and even within evolutionary theory, adaptationism and genetic selection (mainstream) versus anti-adaptationism and multi-level selection (non-mainstream). Today’s scientific debates require a multidisciplinary perspective and an open mind, so that non-mainstream theories can complement the limitations of mainstream theories and contribute to scientific progress.
Until the end of the 16th century, the theory that the Earth was the center of the universe and that the sun and all the stars and planets revolved around it (heliocentrism) was firmly entrenched in people’s thinking. Galilei’s astronomical observations showed that the Earth was not the center of the universe, and that it was just one of several planets revolving around the Sun (geocentrism). However, even with scientific data, it was difficult to change a perception that had been ingrained in people’s thinking for so long. A famous anecdote is that Galilei, who was eventually brought to the Inquisition, quietly said, “But the Earth still turns,” as he left the courtroom.
C.R. Darwin is a similar story. In his book The Origin of Species, he explained the mechanism of adaptation and evolution of living species through natural selection, or evolutionary theory. Darwin argued that the first species adapted to their different environments, and over time, new species arose with features that were adapted to their environment. Today, there is little disagreement in the scientific community about the evolution of life, but in the 18th century, people believed in creationism – the idea that all living things were created by God – and Darwin’s ideas sparked great religious controversy and backlash.
Although evolutionary theory eventually overtook creationism and became the mainstream theory, opinions within evolutionary theory were again divided, splitting into mainstream theories (adaptationism, genetic selection, etc.) and non-mainstream theories (anti-adaptationism, multi-level selection). As in the case of Galilei and Darwin, it is very difficult to establish a new theory that differs from the mainstream, i.e., people’s prevailing ideas. However, just as geodynamics and evolution, once thought to be wrong, were eventually proven to be true, scientific debates should be judged solely from a scientific point of view, excluding personal thoughts, ideas, and preferences.
From this perspective, I oppose adaptationism and gene selection, which are the mainstream theories of evolution, and support anti-adaptationism and multi-level selection. In this regard, I would like to summarize my thoughts after reading Darwin’s Table by Professor Dae-Ik Jang of South Korea.
Darwin’s Table is a fictionalized conversation between a group of evolutionary scholars at the funeral of William Hamilton, one of the greatest evolutionary biologists since Darwin, discussing various issues in evolutionary theory. As the title suggests, the debate features Darwin’s descendants, all of whom support Darwin’s core concept of natural selection. They argue fiercely about the same theory but differ on its application and interpretation. Dawkins’s team, represented by Dawkins, supports the mainstream theory, while Gould’s team, represented by Gould, supports the non-mainstream theory.
First, Dawkins takes the adaptationist position on whether human language is the result of adaptation to the environment or a byproduct of intelligence development. Adaptationism holds that most of the characteristics of a species are the product of adaptation to the environment. However, I believe that human language is a byproduct of environmental adaptation.
First, the human language system is innate and is similar in other primates, such as chimpanzees, and while many different species have speech organs for communication, primates have the most developed grammatical systems and the largest and most intelligent brains compared to other animals, so it makes sense that language is a product of human brain and intelligence development.
Second, experiments in which chimpanzees, one of the most intelligent animals after humans, are taught grammar and asked to form sentences also confirm that human language is a product of intelligence development. The human brain is between one-quarter and one-third larger than that of a chimpanzee, and chimpanzees have a limited ability to learn language, no matter how much they are taught. Humans, on the other hand, can continue to create new sentences based on rules learned in the first few years of life. As humans grow up and develop intelligence, they are able to learn more and more language rules, while other animals are less able to learn much language due to their limited intelligence.
An adaptationist counterargument to this argument is that the complexity and sophistication of language grammar fulfills the requirements for a trait to be considered an adaptation, i.e., a certain level of complexity, and therefore human language can be seen as the result of natural selection. However, the criteria of “complexity” and “sophistication” used by adaptationists are vague, and any phenomenon in the natural world can be interpreted as an adaptation, depending on the human subjectivity that applies the criteria. Therefore, adaptationists need to provide more evidence and clarify the criteria for “sophistication” to improve their logic.
Secondly, let’s look at the phenomenon of “cooperation” in nature. There are many instances where individuals will cooperate with their peers or sacrifice themselves entirely, even if there is no benefit to them. Examples include worker ants and bees.
Dawkins’s team, advocates of the theory of genetic selection, argue that “humans and all animals are survival machines for genes, and are nothing more than vehicles for carrying them around,” which is genetic reductionism. They argue that ants and bees sacrifice themselves to the extreme to spread their genes. Gould’s team counters that while evolution can occur at the gene level, it doesn’t necessarily have to. They argue for multilevel selection, which states that evolution can occur not only at the cell, organ, or individual level, but also at multiple levels, including species, genus, family, class, order, phylum, and clade.
I’m in favor of multilevel selection. This is not to say that genetic selection is entirely wrong, but rather that the levels at which evolution occurs span multiple levels, from the smallest gene strand to the organ, individual, species, and so on. While it’s true that genes are the ultimate source of change through evolution, it’s important to note that evolution is not just genetic change, but change through natural selection. The reason why organisms evolve is because their interactions with nature change in response to changes in the natural environment, and in this process, it is the entire organism that interacts with the environment, not the genes themselves.
There is still a lack of evidence for evolution, so the debate at Darwin’s table is likely to continue. Despite the lack of evidence, productive debates like the one in this book can make a significant contribution to the advancement of the science of evolution. Personally, I believe that there are still many phenomena that cannot be explained by adaptationism and genetic selection, which may be evidence that these theories are not perfect. Rather than being too exclusive about non-mainstream theories, we can improve scientific theories by analyzing the weaknesses of mainstream theories on the assumption that they are correct.
