Both the biologist and the linguist are interested in how language evolved in the natural history of the human species. This process was embedded in the evolution of life from the first self-replicating macro-molecules to the wealth of species living today on Earth. The evolutionary thinker hits, therefore, on a more fundamental question: Is human language the most complex realization of abstract principles that govern the processing of every kind of biological information?
But let us start with the first question: How did language evolve in our natural history? There is not a single science that can answer this question; research on the natural history of language is an interdisciplinary project that must bring together linguists, neurobiologists, social anthropologists, and evolutionary theorists, among others.
If we want to find the evolutionary origin of language, we need foremost a theory of what language is so that we can describe the relation between the general language competence of humans and the specific use of all those languages that were, are, and will be spoken in different human populations. A first idea could be that a language is just the set of all sentences that were ever spoken in some population. But how can a sentence be defined without criteria for whether an utterance is a well-formed combination of words? So, we need to know a grammar, which is nothing more than a rule-governed set of such criteria.
The grammars of, for example, Japanese and English do not look at all alike. Has the biological evolution of the human species, therefore, nothing to tell us about today’s linguistic variety given that it is a result solely of cultural history and nongenetic transmission? On the contrary, according to one of the most influential linguistic theories, Noam Chomsky’s theory of universal grammar, every human inherits the same grammatical competence involving abstract principles of how to learn a language. These principles alone cannot determine the language a child will learn; they contain parameters, the values of which are set by the social environment of the child, so that the rich variety of languages is generated by different individual experiences.
What is innate, and what is acquired in the knowledge of grammar, can be decided only by empirical research, in which human biology and social anthropology must cooperate. Apart from other research on anatomical and physiological prerequisites for language use, the most important question for the biologist involves investigating the neural structures in the brain that implement the different parts of the linguistic competence—from the phonological analysis of utterances, through the generation of syntactic patterns and the semantic understanding of words and sentences, to the pragmatic knowledge of what is expected from the hearer when he or she perceives a certain kind of sentence in a dialogue. The neurobiologist must come to an understanding of how the neural instantiations of partial linguistic competencies are ontogenetically formed, and the zoologist must compare them with homologous parts in the brain of kindred species.
Yet language is, even from a strictly biological point of view, a social phenomenon. No human would speak if there were not others with whom a coordination of behavior is necessary to achieve some individual aims by social action. Therefore, primatologists and anthropologists are asked to explain the coevolution of innate cognitive competencies and social contexts in which the biological evolution of language happened.
The last remark draws our attention to possible evolutionary reasons for the origin of language. It seems evident that language provided a selective advantage for the ancestors of the human species in their struggle for survival because it is superior to any other known system of animal communication. But was language directly selected? Or did there exist some other previously selected mental faculties on the base of which the linguistic competence came into being as a kind of cognitive by-product that was only indirectly selected? Although the second alternative is more complicated than the first alternative, which is the typical answer that would be expected from a Darwinian, the creative possibilities inherent in language speak in favor of the second alternative, which is also compatible with the theory of natural evolution by selection. In contrast to any other system of animal communication, each of the different grammatical systems of human language allows one to construct an endless number of well-formed combinations of words and to communicate the same vast number of thoughts. Because this faculty transcends any direct adaptation to immediate communicative needs, the computational power of human language seems to have its origin rather in a kind of interface between sensory-motor and conceptual-intentional systems that were directly functional as adaptations by natural selection.
To this point, our evolutionary considerations seem to conceive language as a general anthropological characteristic that discriminates humans from any other kind of organism, a point of view that would be in agreement with a long Western philosophical tradition since Aristotle. But although we adopt the thesis that there does indeed appear to be something new in human language in respect to its computational power, we need not deny a second thesis: Human language is the most complex realization of abstract principles that govern the processing of every kind of biological information.
To support this thesis, we must ask whether it is possible to interpret the evolution of life on Earth in general, from the origin of the genetic code through intercellular and neural codes to the evolution of animal communication and of human language, as a history of the discovery and establishment of forms of information processing, which are nothing more than different types of languages. If so, abstract principles governing human language should be found in a more primitive form even on the level of genetic information processing. Since the 1970s, scientists interested in the functional organization of biological information, such as Vadim A. Ratner, Manfred Eigen, and Bernd-Olaf Küppers, have systematically described the linguistic character of genetic information.
Modern genetics conceives heredity as a process of storing, transmitting, processing, and transforming genetic information. To do so, it uses the concept of code for the description of the structure of the material carrier of hereditary factors, the deoxyribonucleic acid (DNA). Let us describe some main features of the linguistic structure of DNA.
- DNA stores genetic information in the sequence of its four nucleotide building blocks that bear no genetic sense separately. Yet they are combined in linear sequences of three nucleotides (called “codons”) that do have a genetic sense. Each codon encodes an amino acid building block of a protein, so that the syntax of codons encodes the linear sequence of amino acids in the polypeptide chain of a protein.
- But if the syntactic structure of DNA can instruct the biosynthesis of proteins, there must exist a set of rules—a code—that attaches an amino acid to each possible codon. Indeed, such a genetic code exists; it defines the semantics of genetic information.
- Like in human language, this genetic semantics is contingent. Although the genetic code is the same in all organisms, the semantic relations of codons to amino acids originated not only in biochemical necessity but also in evolutionary accidents. To explain the origin of genetic semantics, we must discover the singular boundary conditions of its first use, that is, the primitive pragmatics of genetic information in self-replicating molecules.
Our short remarks show that we can describe a language of genes involving the syntactic, semantic, and pragmatic dimensions of genetic information. If we expand our horizon and analyze other kinds of biological information by linguistic means, we are making a further step toward the integration of human language into a general evolutionary perspective on natural and cultural history.
- Hauser, M. D., Chomsky, N., & Tecumseh Fitch, W. (2002). The faculty of language: What is it, who has it, and how did it evolve? Science, 298, 1569-1579.
- Jackendoff, R. (2002). Foundations of language: Brain, meaning, grammar, evolution. Oxford, UK: Oxford University Press.
- Küppers, B.-O. (1990). Information and the origin of life. Cambridge, MA: MIT Press.