Language Evolution and Computation Bibliography

This article presents several factors related to the evolution of vocal and phonetic behaviors thus discussing the emergence of symbolization and reference. Evolutionary theories must identify the environmental changes that produced phenotypic variation and the modes of selection that reinforced certain of the variants, thereby increasing reproductive success, and they must specify the developmental stages in which these actions took place. The primary task of evolutionary theorists is to identify the environmental changes, and the responses to those changes, that edged our ancestors closer to the linguistic capacity possessed by modern humans. A new paradigm, evolutionary developmental linguistics (EDL), a naturalization of human language, is concerned with the evolution of developmental properties, processes, and stages that independently, or in concert with other environmental changes, facilitated the emergence of language in the species. Modern humans have four developmental stages that include infancy, childhood, juvenility, and adolescence. Much of the linguistically relevant phenotypic variation originated in ancestral infancies, with selection by parents occurring in this stage, and, with persistence of selected behaviors, in later stages by peers and others. Juvenility provides additional time for the brain growth and learning required for reproductive success in various species of mammals. The modification of juvenility would naturally increase phenotypic variability and offer new bases for selection at a time when greater independence and sexual maturity were rapidly approaching.

Since language is a biological trait, it is necessary to investigate its evolution, development, and functions, along with the mechanisms that have been set aside, and are now recruited, for its acquisition and use. It is argued here that progress toward each of these goals can ...

Throughout recorded history, sexually mature males have issued humorous insults in public. These averbal duelsa are thought to discharge aggressive dispositions, and to provide a way to compete for status and mating opportunities without risking physical altercations. But, is there evidence that such verbal duels, and sexual selection in general, played any role in the evolution of specific principles of language, syntax in particular? In this paper, concrete linguistic data and analysis will be presented which indeed point to that conclusion. The prospect will be examined that an intermediate form of aproto-syntaxa, involving aproto-Mergea, evolved in a context of ritual insult. This form, referred to as exocentric compound, can be seen as a aliving fossila of this stage of proto-syntax a providing evidence not only of ancient structure (syntax/semantics), but also arguably of sexual selection.

The handicap principle has been applied to a number of different traits in the last three decades, but it is difficult to characterize its record, or even its perceived relevance, when it comes to an important human attribute ''spoken language. In some cases, assumptions regarding the energetic cost of speech, and the veracity of linguistically encoded messages, have failed to recognize critical aspects of human development, cognition, and social ecology. In other cases, the fact that speech contains honest (physiological) information, and tends to be used honestly with family and friends, has been overlooked. Speech and language are functionally related but they involve different resources. Individuals can increase the attractiveness of their speech, and of more stylized vocal and verbal performances, without enhancing linguistic structure or content; and they can modify their use of language without significant changes in the physical form of speech. That its production costs are normally low enables speech to be produced extravagantly in bids for status and mating relationships, and in evolution, may have allowed its content ''linguistic knowledge and structure ''to become complex.

It has long been asserted that the evolutionary path to spoken language was paved by manual-gestural behaviors, a claim that has been revitalized in response to recent research on mirror neurons. Renewed interest in the relationship between manual and vocal behavior draws attention to its development. Here, the pointing and vocalization of 16.5-month-old infants are reported as a function of the context in which they occurred. When infants operated in a referential mode, the frequency of simultaneous vocalization and pointing exceeded the frequency of vocalization-only and pointing-only responses by a wide margin. In a non-communicative context, combinatorial effects persisted, but in weaker form. Manual-vocal signals thus appear to express the operation of an integrated system, arguably adaptive in the young from evolutionary times to the present. It was speculated, based on reported evidence, that manual behavior increases the frequency and complexity of vocal behaviors in modern infants. There may be merit in the claim that manual behavior facilitated the evolution of language because it helped make available, early in development, behaviors that under selection pressures in later ontogenetic stages elaborated into speech.

It has long been claimed that Homo sapiens is the only species that has symbolic language, but only recently recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood---an interval of four years extending between infancy and the juvenile period that follows---and adolescence---a stage of about eight years that stretches from juvenility to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four preadult ontogenetic stages in life history. Then we attempt to trace the evolution of childhood and juvenility in our hominid ancestors. We propose that several different forms of selection applied in infancy and childhood; and that in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language.