Linguistic diversity, now and in the past, is widely regarded to be independent of biological changes that took place after the emergence ofHomo sapiens. We show converging evidence from paleoanthropology, speech biomechanics, ethnography, and historical linguistics that labiodental sounds (such as “f” and “v”) were innovated after the Neolithic. Changes in diet attributable to food-processing technologies modified the human bite from an edge-to-edge configuration to one that preserves adolescent overbite and overjet into adulthood. This change favored the emergence and maintenance of labiodentals. Our findings suggest that language is shaped not only by the contingencies of its history, but also by culturally induced changes in human biology.

This paper introduces a new long-duration travel diary survey undertaken in a small town and rural environment, which complements the existing urban Mobidrive survey of 1999. Policy-making is dominated by the 1-day view of the world provided by the usual diaries. Long-duration surveys can balance this by highlighting the strong intrapersonal variance in choices, modes used and other aspects of travel behaviour. They also allow us to gain an understanding of the activity space of the travellers. The new 2003 Thurgau data followed the protocol of the earlier study, but developed the set of questions further. These new questions concerned the social context of respondents as well as trip-related items, such as planning horizon of the activity, previous frequency of visits or the groups involved in the trip or activity. The descriptive and model-based analysis of the data showed that respondent fatigue is not an issue in either survey. Where significant deviations from a steady number of reported trips were found, they showed positive tendencies, i.e. learning. The skill accrued in the intensive round of contacts between respondent and interviewer is significant. Papers on travel diaries tend not to report interviewer effects, although their impacts are clearly discernable. The analysis shows that the four interviewers employed in this survey had a substantial effect on the number of reported trips. Copyright Springer Science+Business Media, LLC 2007Fatigue, Mobidrive, Switzerland, Thurgau, Travel behaviour, 6-Week travel diary,

Some languages constrain the recursive embedding of NPs to some specific morphosyntactic types, allowing it, for example, only with genitives but not with bare juxtaposition. In Indo-European, every type of NP embedding-genitives, adjectivizers, adpositions, head marking, or juxtaposition-is unavailable for syntactic recursion in at least one attested language. In addition, attested pathways of change show that NP types that allow recursion can emerge and disappear in less than 1,000 years. This wide-ranging synchronic diversity and its high diachronic dynamics raise the possibility that at many hypothetical times in the history of the family recursive NP embedding could have been lost for all types simultaneously, parallel to what has occasionally been observed elsewhere (Everett 2005, Evans & Levinson 2009). Performing Bayesian phylogenetic analyses on a sample of fifty-five languages from all branches of Indo-European, we show, however, that it is extremely unlikely for such a complete loss to ever have occurred. When one or more morphosyntactic types become unavailable for syntactic recursion in an NP, an unconstrained alternative type is very likely to develop in the same language. This suggests that, while diachronic pathways away from NP recursion clearly exist, there is a tendency-perhaps a universal one-to maintain or develop syntactic recursion in NPs. A likely explanation for this evolutionary bias is that recursively embedded phrases are not just an option that languages have (Fitch et al. 2005), but they are in fact preferred by our processing system.*

A critical feature of language is that the form of words need not bear any perceptual similarity to their function -these relationships can be 'arbitrary'. The capacity to process these arbitrary formfunction associations facilitates the enormous expressive power of language. However, the evolutionary roots of our capacity for arbitrariness, i.e. the extent to which related abilities may be shared with animals, is largely unexamined. We argue this is due to the challenges of applying such an intrinsically linguistic concept to animal communication, and address this by proposing a novel conceptual framework highlighting a key underpinning of linguistic arbitrariness, which is nevertheless applicable to non-human species. Specifically, we focus on the capacity to associate alternative functions with a signal, or alternative signals with a function, a feature we refer to as optionality. We apply this framework to a broad survey of findings from animal communication studies and identify five key dimensions of communicative optionality: signal production, signal adjustment, signal usage, signal combinatoriality and signal perception. We find that optionality is widespread in non-human animals across each of these dimensions, although only humans demonstrate it in all five. Finally, we discuss the relevance of optionality to behavioural and cognitive domains outside of communication. This investigation provides a powerful new conceptual framework for the cross-species investigation of the origins of arbitrariness, and promises to generate original insights into animal communication and language evolution more generally.

Two principles shaping agreement paradigms have been implicitly assumed to constitute diachronic universals: (i) ergativity is assumed to be more likely to develop or be maintained in third than in non-third person; (ii) zeros are assumed to develop and be preserved more commonly in third than in non-third person. Estimating probabilities of diachronic change in a worldwide database and controling for areal diffusion effects, we find no evidence for (i). Principle (ii) receives no support either when examining how paradigms develop as systems, but we observe a weak cross-paradigm effect which is likely to be caused by frequency patterns during grammaticalization.