Duality of Patterning

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Duality of patterning refers to the ability of human language, both signed and spoken, to form discrete meaningful units (morphemes; cf. "Rules of word formation (morphology)") from discrete non-meaningful segments (phonemes; cf. "Sound/sign patterning (phonology)"). (1)  No naturally occurring system of animal communication exhibits this basic feature of human language in its entirety. However, there is some evidence for incipient aspects of duality of patterning in the call systems of Campbell's monkeys and putty-nosed monkeys. (2) In other words, individual alarm calls seem to be stripped of their intrinsic “meaning” when combined in certain ways across situational contexts ([3] and Figure 1, below). There have also been reports that after an African gray parrot spontaneously, without training, produced minimal pairs of certain words differing in only one phoneme, he was trained to produce the component phonemes of words he already knew. (4) Hockett (1960) hypothesized that this property was the last to emerge in the evolution of language, precipitated by a certain level of complexity, and this claim appears consistent with studies of emerging sign languages (5).

Composition of alarm call sequences in Diana monkeys (Ouattara et al. 2009)

Timing of appearance of the difference in the Hominin Lineage as a defined date or a lineage separation event. The point in time associated with lineage separation events may change in the future as the scientific community agrees upon better time estimates. Lineage separation events are defined in 2017 as:

  • the Last Common Ancestor (LCA) of humans and old world monkeys was 25,000 - 30,000 thousand (25 - 30 million) years ago
  • the Last Common Ancestor (LCA) of humans and chimpanzees was 6,000 - 8,000 thousand (6 - 8 million) years ago
  • the emergence of the genus Homo was 2,000 thousand (2 million) years ago
  • the Last Common Ancestor (LCA) of humans and neanderthals was 500 thousand years ago
  • the common ancestor of modern humans was 100 - 300 thousand years ago

Probable Appearance: 
100 thousand years ago
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  1. The gradual emergence of phonological form in a new language, Sandler, W., Aronoff M., Meir I., and Padden C. , Natural language & linguistic theory, 05/2011, Volume 29, Issue 2, p.503 - 543, (2011)
  2. Alex & Me, Pepperberg, I. , p.232, (2009)
  3. Campbell's monkeys concatenate vocalizations into context-specific call sequences., Ouattara, Karim, Lemasson Alban, and Zuberbühler Klaus , Proc Natl Acad Sci U S A, 2009 Dec 22, Volume 106, Issue 51, p.22026-31, (2009)
  4. A syntactic rule in forest monkey communication, Zuberbühler, Klaus , Animal Behaviour, Volume 63, p.293 - 299, (2002)
  5. The Origin of Speech, Hockett, C. , Scientific American, Volume 203, Issue 3, p.88-96, (1960)