Using a symbolic dynamics and a surrogate data approach, we show that the language exhibited by common fruit flies Drosophila (‘D.’) during courtship is as grammatically complex as the most complex human-spoken modern languages. This finding emerges from the study of fifty high-speed courtship videos (generally of several minutes duration) that were visually frame-by-frame dissected into 37 fundamental behavioral elements. From the symbolic dynamics of these elements, the courtship-generating language was determined with extreme confidence (significance level > 0.95). The languages categorization in terms of position in Chomsky’s hierarchical language classification allows to compare Drosophila’s body language not only with computer’s compiler languages, but also with human-spoken languages. Drosophila’s body language emerges to be at least as powerful as the languages spoken by humans.
References
[1]
Chomsky N (1956) Three models for the description of language. Information Theory, IRE Transactions on 2: 113–124.
[2]
Chomsky N (1986) Knowledge of Language: its Nature, Origin, and Use. Praeger Publishers, Westport C.
[3]
Hauser MD, Chomsky N, Fitch WT (2002) The faculty of language: What is it, who has it, and how did it evolve? Science 298: 1569–1579.
[4]
Pinker S, Bloom P (1990) Natural language and natural selection. Behavioural and Brain Sciences 13: 707–727.
[5]
Chomsky N (1988) Language and Problems of Knowledge. MIT Press, Cambridge, MA.
[6]
Shinbrot T, Young W (2008) Why decussate? Topological constraints on 3d wiring. The Anatomical Record 291: 1278–1292.
[7]
Chomsky N, Schützenberger MP (1963) The algebraic theory of context-free languages. In: Braffort P, Hirschberg D, editors, Computer Programming and Formal Systems, Elsevier, volume 35 of Studies in Logic and the Foundations of Mathematics. 118–161.
[8]
Hagiwara R, Shudo A (2004) Grammatical complexity for two-dimensional maps. J Phys A: Math Gen 37: 10545–10559.
[9]
Shieber SM (1985) Evidence against the context-freeness of natural language. Linguistics and Philosophy 8: 333–343.
[10]
Pullum GK, Gazdar G (1982) Natural languages and context-free languages. Linguistics and Philosophy 4: 471–504.
[11]
Stoop R, Arthur JBI (2008) Periodic orbit analysis demonstrates genetic constraints, variability, and switching in drosophila courtship behavior. Chaos 18: 023123.
[12]
Stoop R, Joller J (2011) Mesocopic comparison of complex networks based on periodic orbits. Chaos 21: 016112.
[13]
Hopcroft J, Ullman J (2007) Introduction to Automata Theory, Languages, and Computation. Prentice Hall, New Jersey.
[14]
Finch T (2010) Three meanings of recursion. In: Larson R, Déprez V, Yamakido H, editors, The Evolutions of Human Language, Cambridge University Press, Cambridge.
[15]
Hofstadter DR (1979) G？del, Escher, Bach: An Eternal Golden Braid. Basic Books, New York.
