At Grammatical Faculty of Language, Flies Outsmart Men

Abstract

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.

Deviation from Criticality in Functional Biological Networks

“…However we do claim that the male behaviour network and the male and female behaviour network are inconsistent with a scale-free structure. This observation is particularly interesting in light of an earlier result [17] which showed not only that DPC language often exhibits recursion (making it to the best of our knowledge the only known animal example of a Context-Free or Context-Sensitive language in the Chomsky hierarchy) but that this recursive property is predominantly exhibited in male DPC. It seems possible that the inclusion of such high level grammar precludes a scale-free network structure.…”

“…With the introduction of significant recursion however, the power law fit breaks down, and instead a network growth algorithm which includes a second process (internal preferential linking with saturation, breaking the scale-free preferential attachment process), is able to match these network structures (but not the scale-free one) without fitting. Recursion is essential for higher level abstract reasoning [17], and requires a secondary "book keeping" function to keep track of the references between elements. It appears from the above evidence that such a second process is neccessary for the male behaviour, and incompatible with a critical state.…”

“…Sequences of these fundamental actions naturally define a network, which gives a glimpse of the topology of transitions between relevant neural states expressable by the system. Further, these sequences have been shown to convey important and specific information with a broad range of grammatical sophistication [15,16,17].…”

Excess entropies reveal higher organization levels in developing neuron cultures

“…Formal languages, first used to classify computer and human spoken languages [10][11][12][13], have recently added important insight in dynamical systems, in theory and in applications [14][15][16][17]. Dynamical systems map a generically chosen initial condition into a sequence S = {s(t 1 ), s(t 2 ), .…”

“…f (N; N, p) does not embrace the order by which the states are visited and therefore does not retain information regarding the underlying system dynamics. To capture the latter aspect, we consider at each position n of the sequence the walkthrough probability [17] which evaluates for each symbol s j (n) the probability that a random walk starting with symbol s 1 will pass through symbol s j (i.e. P in (s j )), times the probability that a random walk starting at s j will end with symbol x L (ie, P out (s j )) P (n, N; n, N, p) = f (n; n, p)f (N − n; N − n, p) = n!…”