Claire Bowern and Kevin Zhou publish paper on Australian numeral systems

Claire Bowern and Yale Biomedical Engineering student Kevin Zhou have published a paper examining the evolution of numeral systems in the indigenous languages of Australia. “Quantifying uncertainty in the phylogenetics of Australian numeral systems” appears in the September 2015 issue of Proceedings of the Royal Society B. The original paper is available here, and an article on the research was also featured in the Australian Broadcasting Corporation website. The abstract of the paper appears below:

“Researchers have long been interested in the evolution of culture and the ways in which change in cultural systems can be reconstructed and tracked. Within the realm of language, these questions are increasingly investigated with Bayesian phylogenetic methods. However, such work in cultural phylogenetics could be improved by more explicit quantification of reconstruction and transition probabilities. We apply such methods to numerals in the languages of Australia. As a large phylogeny with almost universal ‘low-limit’ systems, Australian languages are ideal for investigating numeral change over time. We reconstruct the most likely extent of the system at the root and use that information to explore the ways numerals evolve. We show that these systems do not increment serially, but most commonly vary their upper limits between 3 and 5. While there is evidence for rapid system elaboration beyond the lower limits, languages lose numerals as well as gain them. We investigate the ways larger numerals build on smaller bases, and show that there is a general tendency to both gain and replace 4 by combining 2 + 2 (rather than inventing a new unanalysable word ‘four’). We develop a series of methods for quantifying and visualizing the results.”