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The Major Transitions in the Evolution of Language
... This is, in general, true for the evolution of any complex trait, including speech: Each contribution to the trait must have increased fitness. Hence, evolution of complex traits happens along a "path of ever increasing fitness" (Zuidema, 2005). This is something that needs to be kept in mind when proposing scenarios for the evolution of a complex trait: Not only does the eventual (complete) complex trait need to provide a fitness benefit, each intermediate (incomplete) stage also needs to provide a fitness benefit. ...
Purpose
This article critically reviews work on the evolution of speech in the context of motor control. It presents a brief introduction to the field of language evolution, of which the study of the evolution of speech is an integral component, and argues why taking the evolutionary perspective is useful. It then proceeds to review different methods of studying evolutionary questions: comparative research, experimental and observational research, and computer and mathematical modeling.
Conclusions
On the basis of comparative analysis of related species (specifically, other great apes) and on the basis of theoretical results, this article argues that adaptations for speech must have evolved gradually and that it is likely that speech motor control is one of the key aspects that has undergone observable selection related to speech, because, in this area, all the necessary precursors are present in closely related species. This implies that it must be possible to find empirical evidence for how speech evolved in the area of speech motor control. However, such research is only in its infancy at the present moment.
... In this chapter I propose that with this insight we can take the MS&S's ideas much further and look within this new system of replication for evolutionary transitions that bear striking similarities to those seen in the broader evolutionary history of life. ese major transitions in linguistic evolution are primarily non-biological, involving an evolution of the systems of linguistic phenotypic replication, but they are likely to interact with ongoing biological evolution of humans in interesting ways that we are only beginning to understand (see also, Zuidema (2005) for discussion of transitions in linguistic evolution that have both cultural and biological implications.) I will discuss here three candidates for major transitions: ...
Maynard Smith and Szathmáry (1995) propose a series of major transitions in the evolutionary history of life. Their work provides a rich framework for thinking about replication. They identified the importance of language in this light, but language is a new system of replication in more than one sense: it is both an enabler of cultural replicators with unlimited heredity, and also a new kind of evolutionary system itself. Iterated learning is the process of linguistic transmission, and it drives both language change and the transitions to qualitatively new kinds of linguistic system. By seeing language as an evolutionary system, the biggest payoff we get may be the ability to take biologists’ insights into the evolution of life and apply them to the evolution of language.
... Language is a complex concept, not easy to define in any stringent manner even in modern humans, and there is a regrettable lack of consensus among linguists, to the extent that the field can be called poly-paradigmatic (Zuidema 2005). The links between linguistic theory and neurological observables in the brain are also tenuous at best (Poeppel & Embick 2005, Deacon 2006, Fedor et al. 2009). ...
Did Neanderthals have language? This issue has been debated back and forth for decades, without resolution. But in recent years new evidence has become available. New fossils and archeological finds cast light on relevant Neanderthal anatomy and behavior. New DNA evidence, both fossil and modern, provides clues both to the relationship between Neanderthals and modern humans, and to the genetics of language. In this paper, I review and evaluate the available evidence. My conclusion is that the preponderance of the evidence supports the presence of at least a spoken proto-language with lexical semantics in Neanderthals.
... really in line with the first approach, because it was assumed that the sets of messages M and M were disjoint, and that all these messages have already separate meanings. Unfortunately, Nowak & Krakauer's (1999) explanation of the emergence of compositional languages has been criticized on several points, and I believe these points are well-taken. Zuidema (2004), for instance, rightly criticizes the implicitly adopted assumption that we just compare a holistic versus a (pre-existing) compositional language to see which one comes out best (in terms of invasion barrier). By adopting this assumption one already assumes that compositional languages are possible, but does not explain how they can em ...
Most work in 'evolutionary linguistics' seeks to motivate the emergence of linguistic universals. Although the search for universals never played a major role in semantics, a number of such universals have been proposed concerning connectives, property and preposition denoting expressions, and quantifiers. In this paper we suggest some evolutionary motivations for these proposed universals using game theory.
... do not address that specific problem mathematically. They do, however, perform a mathematical, game-theoretic analysis of the evolution of "compositionality", and point out that this analysis can be adapted easily to the case of combinatorial phonology, as is worked out in Zuidema (2005). ...
A fundamental, universal property of human language is that its phonology is combinato-rial. That is, one can identify a set of basic, distinct units (phonemes, syllables) that can be productively combined in many different ways. In this paper, we review a number of theories and models that have been developed to explain the evolutionary transition from holistic to combinatorial signal systems, but find that in all problematic linguistic assumptions are made, or crucial components of evolutionary explanations are omitted. We present a novel model to investigate the hypothesis that combinatorial phonology results from optimising signal systems for perceptual distinctiveness. Our model differs from previous models in two important respects. First, signals are modelled as trajectories through acoustic space. Hence, both holistic and combinatorial signals have a temporal structure. Second, we use the methodology from evolutionary game theory. Crucially, we show a path of ever in-creasing fitness from holistic to combinatorial signals, where every innovation represents an advantage even if no-one else in a population has yet obtained it.
... Starting with a 'seed' of completely random unstructured signals, a population can develop a highly-organized system through an iterative cultural transmission process distributed over space and time, without any 'biological' change in the makeup of the agents being required. Of particular interest is the emergence of vowel systems (de Boer 2001; Oudeyer 2003) and of grammatical regularities (Kirby 1998; Zuidema 2005) that often bear only an indirect relationship to constraints built in to the model. Relatively general constraints at the perceptual or cognitive level can lead to quite specific effects on the structure of the evolved communication systems in a short time period. ...
For many years the evolution of language has been seen as a disreputable topic, mired in fanciful “just so stories” about
language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian
evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language.
I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species
to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species,
from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language,
and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the “descended
larynx” of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims
is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties
animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation
in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between
parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny,
discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude
that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our
most distinctively human trait: language.
... In fact, with hindsight it is understandable that trajectories would stretch out over the diagonal, as this results in a larger distance between the points on the stretched out trajectory and the trajectories in the corners than for a trajectory bunched up in the center. The average distance of points on the trajectory to the two corners it visits remains equal, while the average distance to the two corners it does not visit increases (Zuidema, 2005). The situation is less clear for larger numbers of trajectories . ...
A fundamental characteristic of human speech is that it uses a limited set of basic building blocks (phonemes, syllables), that are put to use in many different combinations to mark differences in meaning. This article investigates the evolution of such combinatorial phonology with a simulated population of agents. We first argue that it is a challenge to explain the transition from holistic to combinatorial phonology, as the first agent that has a mutation for using combinatorial speech does not benefit from this in a population of agents that use a holistic signaling system. We then present a solution for this evolutionary deadlock. We present experiments that show that when a repertoire of holistic signals is optimized for distinctiveness in a population of agents, it converges to a situation in which the signals can be analyzed as combinatorial, even though the agents are not aware of this structure. We argue that in this situation adaptations for productive combinatorial phonology can spread.
Individuals affected with developmental disorders of speech and language have substantial difficulty acquiring expressive and/or receptive language in the absence of any profound sensory or neurological impairment and despite adequate intelligence and opportunity(1). Although studies of twins consistently indicate that a significant genetic component is involved(1-3), most families segregating speech and language deficits show complex patterns of inheritance, and a gene that predisposes individuals to such disorders has not been identified. We have studied a unique three-generation pedigree, KE, in which a severe speech and language disorder is transmitted as an autosomal-dominant monogenic trait(4). Our previous work mapped the locus responsible, SPCH1, to a 5.6-cM interval of region 7q31 on chromosome 7 (ref. 5). We also identified an unrelated individual, CS, in whom speech and language impairment is associated with a chromosomal translocation involving the SPCH1 interval(6). Here we show that the gene FOXP2, which encodes a putative transcription factor containing a polyglutamine tract and a forkhead DNA-binding domain, is directly disrupted by the translocation breakpoint in CS. In addition, we identify a point mutation in affected members of the KE family that alters an invariant amino-acid residue in the forkhead domain. Our findings suggest that FOXP2 is involved in the developmental process that culminates in speech and language.
The idea that natural language grammar and planned action are related systems has been implicit in psychological theory for more than a century. However, formal theories in the two domains have tended to look very different. This article argues that both faculties share the formal character of applicative systems based on operations corresponding to the same two combinatory operations, namely functional composition and type-raising. Viewing them in this way suggests simpler and more cognitively plausible accounts of both systems, and suggests that the language faculty evolved in the species and develops in children by a rather direct adaptation of a more primitive apparatus for planning purposive action in the world by composing affordances of objects or tools. The knowledge representation that underlies such planning is also reflected in the natural language semantics of tense, mood, and aspect, which the paper begins by arguing provides the key to understanding both systems.
Conflicts between animals of the same species usually are of ``limited
war'' type, not causing serious injury. This is often explained as due
to group or species selection for behaviour benefiting the species
rather than individuals. Game theory and computer simulation analyses
show, however, that a ``limited war'' strategy benefits individual
animals as well as the species.
Human languages are universally phonemically coded, whereas many animal signal systems are not. A number of theories and models have been developed to explain this evolutionary tran- sition, but some major problems remain. We present a simulation to investigate the hypothesis that phonemic coding is an side effect of optimizing signal systems for success in imitation. Cru- cially, signals in our model are trajectories in an (abstract) acoustic space. Hence, both holistic and phonemically coded signals have a temporal structure. Using both qualitative inspection of emerged systems of trajectories and a statistical analysis of a measure of phonemicity, we find that phonemically coded systems are indeed preferred. The model thus provides a new explanations for the evolutionary pathway to the emergence of phonemic coding.
Acoustic analyses and experimental field playbacks were conducted to investigate the nature and communicative significance of the phonological structure and organization of male gibbon (Hylobates agilis) songs. Males use a limited number of spectrographically discrete elements or note types to construct songs. A classification of these note types was produced initially through a visual sorting process using gross spectral and temporal features. Measurement of single acoustic variables and a digital sound program, which compared the two-dimensional cross-correlation values of note spectrograms, were employed to check the results of the qualitative sorting procedure. The sequential organization of notes composing songs was examined by tabulating the frequencies of occurrence of each note type in different positions and the transition probabilities between note types. These analyses revealed that songs are formed within a framework of rules, which define regular patterns in the placement and order of note types. To investigate whether the gibbons employ these rules in a biologically meaningful fashion, a field playback experiment was conducted comparing the responses of animals to normal and phonologically rearranged songs. Although the gibbons identify rearranged songs as conspecific territorial signals, responses to playbacks suggested that the hypothesized rules generating songs are communicatively significant; male gibbons responded in a qualitatively different fashion to normal and phonologically rearranged songs. These results are evaluated in light of other studies of animal vocal communication.
A fundamental goal of linguistic theory is to explain how natural languages are acquired. This paper describes some recent findings on how learners acquire syntactic knowledge for which there is little, if any, decisive evidence from the environment. The first section presents several general observations about language acquisition that linguistic theory has tried to explain and discusses the thesis that certain linguistic properties are innate because they appear universally and in the absence of corresponding experience. A third diagnostic for innateness, early emergence, is the focus of the second section of the paper, in which linguistic theory is tested against recent experimental evidence on children's acquisition of syntax.