In this blog post, we will explore whether the origin of chickens is the result of evolution through natural selection or a product of human intelligence and intervention, examining various studies and perspectives.
There’s a saying: “Which came first, the chicken or the egg?” It is already known that the age of the Earth, and indeed the universe, is finite. So where did the first chicken come from? Chickens hatch from eggs, yet the first chicken had no parents to lay the egg it would hatch from. The answer to this paradox can be found in Darwin’s 1859 publication, On the Origin of Species. Biological individuals possess different characteristics, and only those with competitive traits leave offspring and pass their genes to future generations. Thus, organisms evolve by passing on suitable genes. The process where only competitive individuals survive is called natural selection, and organisms acquiring traits suited to nature is called adaptation. Organisms evolved from self-replicating chemical molecules into chickens through natural selection, and through this evolutionary process, they developed into humans capable of narrative.
Adaptation explains many characteristics of organisms. For example, polar bears living in snowy environments must have fur similar to snow to remain inconspicuous. Bears with dark fur stand out, making them easy prey for predators and difficult to hunt. Consequently, their numbers would gradually decline, leaving only white polar bears. Thus, the polar bear’s white fur is the result of adaptation. Adaptation is the core of evolution, explaining variation at the species level. Language, one of humanity’s key characteristics, is also a product of adaptation. There is evidence supporting linguistic adaptationism.
The human vocal apparatus consists of highly complex organs that function organically to produce sound. These vocal organs would be unnecessary if they were not used to speak language for communication. Evolution occurs in a direction that preserves traits advantageous for survival. Therefore, the existence of vocal organs is justified because communication through language conferred a survival advantage, and language itself can be seen as an outcome of adaptation.
Furthermore, according to developmental psychology, there is a critical period for the development of human language ability. Development is largely completed during this critical period; conversely, failure to develop during this time leads to language disorders. A case study demonstrating this is the Wolf Boy of Aveyron, France. Raised among wolves as a child, this boy reportedly could not speak human language upon discovery and only howled like a wolf. Despite years of care and surrounding efforts after his rescue, he ultimately failed to acquire language. The critical period demonstrates the innate aspect of language acquisition, strongly suggesting that language emerged through genetic and evolutionary processes.
Finally, there is research on the language-related gene FOXP2. FOXP2 directly influences language ability. Individuals with mutations in this gene exhibit severe impairments in pronunciation and grammatical comprehension. This gene is also present in chimpanzees, but a mutation that occurred 120,000 years ago appears to have differentiated human FOXP2 from that of chimpanzees. Meanwhile, archaeological research suggests culture emerged around 120,000 years ago. Considering culture’s close connection to human communication—specifically language—language itself likely emerged around the same time. This coincides with the timing of the FOXP2 gene mutation, leading scholars to speculate that language’s emergence is linked to this gene. Therefore, language can be viewed as an outcome of adaptation.
There are opposing views to this linguistic adaptationist perspective. Paleontologist Gould and linguist Chomsky argue that language did not arise through adaptation but is instead a byproduct of the large human brain. That is, like a spandrel—a secondary structure supporting an arch—language is a byproduct that emerged as the brain grew larger. However, there is some evidence contradicting their claims. Developmental biology shows that humans, chimpanzees, starlings, and parrots possess similar vocal organs. Considering that chimpanzees, starlings, and parrots do not possess brains as large as humans, these vocal organs cannot be byproducts of brain evolution. Rather, it is more reasonable to explain that these vocal organs developed because communication positively impacted survival. In this explanation, language, which evolved alongside the vocal apparatus, can also be seen not as a byproduct but as an outcome of adaptation. Furthermore, many creatures communicate without possessing large brains. For instance, bees perform ∞ or 0-shaped dances to inform their peers of honey locations. The shape and speed of the dance are determined by the relative positions of the honey, the bee, and the sun. Another example is ants, which leave pheromones while foraging for food. They only leave pheromones on shortcuts or easy-to-travel paths. Subsequent ants reference the trail left by the preceding ant and deposit pheromones on the good path they themselves discovered. Through this process, when multiple ants go out to find food, the path marked with pheromones becomes the optimal shortcut. Once all the food is brought back, the ants do not leave pheromones on the return path. As the scent of the pheromones fades, subsequent ants set out to find other food sources. Even insects, considered to have relatively simple biological structures, possess complex communication systems. Therefore, such communication cannot be viewed as a byproduct of the brain but must be seen as the result of adaptation. Viewing only human complex grammar as language is an inappropriate perspective that ignores the primary function of language as communication and its evolutionary aspects, focusing solely on the characteristics of grammar itself.
Another opposing view to linguistic adaptationism is Chomsky’s argument that language cannot arise through adaptation because its primary function is soliloquy. If soliloquy is language’s primary function, then improving survival rates through communication and subsequent natural selection becomes impossible. Even if we accept Chomsky’s claim that language’s primary function is soliloquy, why did humans acquire language over countless millennia? It is because soliloquy positively influences intelligence development. Just as indigenous peoples with diverse linguistic expressions for color possess superior color perception, language directly influences thought even when not communicated. Even if language’s function is primarily soliloquy, as Chomsky argues, language is ultimately an adaptive outcome.
The evolutionary process related to language’s emergence requires extensive time and many generations, making it difficult to replicate in a laboratory. Therefore, the answer to how language evolved biologically can only be obtained by inferring the process in reverse. However, recent research on language evolution is being conducted through simulations. These studies confirm that language evolves from primitive communication into a language with grammar, supporting the claim that language developed through adaptation.
Language is thus the result of adaptation through natural selection of genes. According to Dawkins, humans are merely survival machines for carrying genes, and the emergence of language could occur universally in any organism. Yet, as the phrase ‘humans are linguistic animals’ reveals, we tend to view language as a uniquely human trait. This tendency leads to the idea that language was not evolutionarily derived but created by humans, often expressed as a ‘byproduct of the large brain’. Dawkins states that evolutionary theory does not provide value judgments about what is right, but rather tells us what is true. That is, evolutionary theory does not provide a standard for value judgments. It merely describes biological facts. The value of humanity’s countless achievements made through language—such as beautiful poetry or exquisite novels—is not diminished simply because language is a natural product of evolution.
