Scars for survival: high cost male initiation rites are strongly associated with desert habitat in Pama-Nyungan Australia

Costly ritual behaviours have frequently been of interest to evolutionary researchers seeking to understand whether they have an adaptive benefit. Here we examine the costliness of initiation rituals across a large group of hunter-gather societies in Pama-Nyungan Australia and compare these with a range of possible adaptive benefits, including warfare, food sharing, demography, and mate competition. We find that in Australia, desert habitat was mostly strongly associated with these rites. Such rites may support the collective action, such as food sharing, necessary for survival in such a precarious environment

The evolution of cultural diversity in Pama-Nyungan Australia

Explaining the processes that produce cultural diversity has long been a focus of anthropological study. Whilst linguistic diversity has frequently been shown to be associated with population splitting during migrations, much less is known about the influence of migration patterns on other forms of culture. Here we compare variation between different cultural types to understand whether their diversity might also be a consequence of historic population change. For our case study, we developed a dataset of 90 cultural traits recorded across around 100 societies in Pama-Nyungan Australia focusing on three cultural forms important in Australian life: adolescent initiation, mortuary practice and rock art motifs. Trait diversity was analysed using phylogenetic methods and compared with language diversity since previous studies have suggested an association between Pama-Nyungan language evolution and population dispersal. We were able to demonstrate a strong association between the phylogenetic history of language and initiation ritual but not between language and mortuary ritual or rock motifs. The finding suggests population migration may have had a significant influence on initiation ritual diversity. It also lends support to the idea, as suggested by some authors, that the development of complex initiation practices may have played an active role in the dispersal of Pama-Nyungan speakers throughout the Australian continent. Our study results suggest that the type of phylogenetic comparative approach applied here can make an important contribution to the reconstruction of deep cultural history over long timescales

Ritual Evolution in Pama-Nyungan Australia

Ritual is present in all societies and plays a pivotal role in many. Its universality and importance, together with uncertain benefits, means it has long been a subject of interest to anthropologists. This study contributes to this field through a comparative examination of ritual variation in Pama-Nyungan Australia using phylogenetic methods. The documented language expansion of these societies, and the role ritual may have played in this, make them a particularly relevant case study for analysis. 90 ritual traits were recorded across around 100 Pama-Nyungan societies focusing on three ritual forms important in Australian life: adolescent initiation, mortuary practice and rock motifs. Analysis was in three parts: a broad examination of ritual variation by form, a higher resolution analysis of individual traits, and a comparison with ecological and sociological influences. The key findings were, firstly, cultural inheritance had a significant influence on initiation and rock motif variation, but less effect on mortuary practice. Secondly, costly initiation rites were particularly associated with linguistic diversity, suggesting they may have played a role in Pama-Nyungan language expansion. Thirdly, there was a clear association between such rites and the occupation of desert habitats. Whilst these may have facilitated closer within-group alliances (theorised by a number of authors) contextual analysis did not indicate that collective practices such food sharing or warfare were particularly different in these societies. What did appear different was the presence of a greater volume and complexity of mythical-geographic knowledge. Such knowledge is particularly important to those inhabiting the Australian desert, providing information on routes between water sources and productive foraging grounds. Traumatic rites may result in prolonged ritual exegesis and it is possible that accumulating this knowledge was the primary impetus for developing costly rites in Australia

The evolution of cultural diversity in Pama-Nyungan Australia

Abstract Explaining the processes that produce cultural diversity has long been a focus of anthropological study. Whilst linguistic diversity has frequently been shown to be associated with population splitting during migrations, much less is known about the influence of migration patterns on other forms of culture. Here we compare variation between different cultural types to understand whether their diversity might also be a consequence of historic population change. For our case study, we developed a dataset of 90 cultural traits recorded across around 100 societies in Pama-Nyungan Australia focusing on three cultural forms important in Australian life: adolescent initiation, mortuary practice and rock art motifs. Trait diversity was analysed using phylogenetic methods and compared with language diversity since previous studies have suggested an association between Pama-Nyungan language evolution and population dispersal. We were able to demonstrate a strong association between the phylogenetic history of language and initiation ritual but not between language and mortuary ritual or rock motifs. The finding suggests population migration may have had a significant influence on initiation ritual diversity. It also lends support to the idea, as suggested by some authors, that the development of complex initiation practices may have played an active role in the dispersal of Pama-Nyungan speakers throughout the Australian continent. Our study results suggest that the type of phylogenetic comparative approach applied here can make an important contribution to the reconstruction of deep cultural history over long timescales