Though my target article (Bichakjian 1999) was on the evolution of linguistic features, in his commentary, Suddendorf (1999) addresses the question of the origin of language and points out the risks of advocating too recent an emergence. My reply stresses that the evidence from historical linguistics and all other evolutionary indicators goes against the saltationist scenarios, and that language evolution has been a gradual process which probably started hundreds of millennia ago. A reply is also given to the question raised about the shift from aspect to tense.
2. While these remarks are informative and a call to caution is always useful, the fundamental question was left unanswered. Indeed, it was not even addressed, because the real issue is not whether the origin of language should be pushed a few tens of millennia one way or the other, but whether language sprang forth in a steady state as Homo sapiens speciated, or whether rudimentary linguistic implements appeared in a faraway member of the Homo genus and gradually evolved to become those that we use today. The members of the MIT school of linguistics advocate the Athena-like scenario because their methodological scheme is built on the steady state conception of language. On the other hand, palaeontologists and many other scientists, who see indications of Broca- and Wernicke-like areas in the fossil skulls of Homo habilis (Tobias 1991), or enlarged hypoglossal canals in hominids living hundreds of millennia ago (Kay et al. 1998, but see also DeGusta et al. 1999), or signs of larger nerves going to the rib cage, where they play a role in speech production (MacLarnon, 1996), present data that support the gradualist view of language evolution.
3. My target article, which showed that, from as far back as we can observe and reconstruct them, languages have been steadily replacing the ancestral implements with ever more advantageous alternatives (linguistically more powerful and biologically less costly), provided data that clearly suggest there is no empirical support for the steady state conception, and that language evolution is a gradual process with roots going very far back in time. Indeed, just as industry started with primitive tools and weapons and steadily evolved into the sophisticated hardware available to us to day, so language began with an improvised set of features which were consistently remodelled into ever more efficient instruments of thought and communication.
4. The informative value, therefore, of saying that such and such an ancestor had language is not much greater than saying that a given member of the Homo genus had industry. The question is not whether or not they had industry, but in which stage of development that industry was. The archaeological data can provide an answer for industry. In the case of language, there are no carbon-dated artefacts, but palaeontology does offer some very useful indications. Endocasts have revealed that Homo habilis was probably endowed with Broca- and Wernicke-like cerebral centres, and studies have concluded that hominid species living hundreds of millennia ago had enlarged bundles of nerve fibres controlling the minute movements of the tongue and the finely tuned contractions of thoracic muscles. When the development of these central and peripheral correlates of speech is combined with the steady evolution of linguistic features, language emerges as an entity that, very much like industry, started with rudimentary implements and developed into the high-performance instrument of thought and communication we are using today.
5. This brings me to the oft-quoted Athena-II scenario, whereby language was acquired in two successive jumps; first, ancestral hominids became genetically endowed with a rudimentary form of communication called "protolanguage," and then the Homo sapiens sapiens genome became enriched with the correlates of a complete set of linguistic implements. Since this is an unsubstantiated scenario, and one that probably will forever remain as such, those who accept it can only accept it on faith, and the freedom to do so is admittedly an indisputable right. But when the focus is laid not on faith, but on facts, one is reminded first of all that Natura saltum non facit. Evolution is a gradual process, and we see it clearly in the evolution of humans from the earliest hominids to today's human beings. Likewise there is continuity from the earliest most rudimentary implements to today's high-tech instruments. Evolution is of course made of tiny incremental steps, as seen for instance in the increase of the cerebral mass, the step-by-step achievement of bipedalism or the successive discoveries of ever more powerful sources of energy, but these tiny incremental steps form a steady continuum. Nature does not make jumps, nor does technology, and there is no empirical evidence, nor even empirical indications which suggest that grammar made jumps. Instead, the existing data support the opposite view.
6. Second, the scheme whereby grammar would have reached criterion on the second jump is as vacuous as claiming that industry achieved criterion in the paleolithic period or during the industrial revolution. Grammar, like industry, is an open-ended entity; it does not reach criterion, it keeps developing according to the principles of natural selection. Such a process is clearly visible in the history of languages during the last six or seven millennia, and the process is pursuing its course, as it does in technology and biology. Since it is based on the same implausible and counterfactual scheme as the original model, the Athena-II version remains equally unacceptable in the light of what we otherwise know about grammar and its evolution during its observable period.
7. In a short footnote appended to his ex-cursus, Suddendorf refers to my argument that "the linguistic invention of tense might have freed our minds from the constraints of the present," and points out that Suddendorf and Corballis (1997) have argued instead that "the ability to generate the mental experience of past and future probably preceded the ability to communicate it." Such a view seems plausible to me, but I see no contradiction, because we are talking about two different things: "generating the mental experience of past and future" is one thing; the categorial conception of past (and future) is another. Memory and projection were admittedly there all along, but the linguistic shift from aspect to past tense and later from mood to future tense provided speakers with the formal means to categorise that experience, store it in temporally organised mental structures, and communicate it with its categorial value. The development that took place can be understood when compared with the acquisition of any word, but especially with that of a word such as 'arrogant'. Before the lexical item is learned and the concept is formalised, speakers would no doubt experience some sort of displeasure and perceive an air of haughtiness in the behaviour, but unless they have acquired the word 'arrogant' as a lexical item and as a concept, they can neither categorise the observed attitude, nor store it in their minds in a sufficiently detailed and organised manner, nor can they communicate it with its categorial precision. The development of tense was a major development accomplishment in the organisation of mental structures.
Bichakjian, B.H. (1999) Language Evolution and the Complexity Criterion. PSYCOLOQUY 10(33). ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.033.language-complexity.1.bichakjian http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.033
MacLarnon, A. M. & Hewitt, G. (1999) The evolution of human speech the role of enhanced breathing control. American Journal of Physical Anthropology 109: 341-363.
DeGusta, D., Gilbert, W. H. & Turner, S.P. (1999) Hypoglossal canal size and hominid speech. Proceedings of the National Academy of Sciences, USA 96:1800-04.
Kay, R. F., Cartmill, M. & Balow, M. (1998) The Hypoglossal Canal and the Origin of Human Vocal Behavior. Proceedings of the National Academy of Sciences, USA 95: 5417-19.
Suddendorf, T. (1999) Reconstructing the Evolution of Language: 'Early-Bloomer' Versus 'Late-Bloomer' Theories. Commentary on Bichakjian on Language-Complexity. ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.080.language-complexity.2.suddendorf http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.080
Suddendorf, T., & Corballis, M.C. (1997). Mental time travel and the evolution of the human mind. Genetic, Social and General Psychology Monographs, 123, 133167.
Tobias, P. V. (1991) The Emergence of Spoken Language in Hominid Evolution. Cultural Beginnings: Approaches to Understanding Early Hominid Life-Ways in the African Savanna, ed. J. D. Clark, Bonn: Habelt, pp. 67-78.