Cathcart, C. | bioRxiv Science

bioRxiv2025

A Phylogenetic Perspective on the Syntax-Semantics Interface: A Case Study in Clause Linkage Constructions

We examine the syntax-semantics interface in clause linkage using a cross-linguistic sample of nearly 700 constructions from Indo-European, Sino-Tibetan, and Tupi-Guarani. To evaluate predictions from the Interclausal Relations Hierarchy, we model the phylogenetic dynamics of how semantic relations influence the degree of syntactic integration between clauses. The best performing model assumes an Ornstein-Uhlenbeck process in each family and suggests only moderate and lineage-specific effects of semantics on syntax, challenging the universality of the Interclausal Relations Hierarchy. Furthermore, geographic proximity exerts only minimal effects, consistent with the notion that the syntax-semantics interface may be more resistant to contact effects than overtly signaled and transparent patterns in language. Together, our findings suggest that the syntax-semantics interface is less constrained in clause linkage than is commonly assumed in typology. They furthermore highlight the value of treating phylogeny as a dynamic evolutionary process, rather than as a static background structure.

evolutionary biology↗

bioRxiv2024

Animal acoustic communication maintains a universal optimum rhythm

Most animals interact with conspecifics through acoustic signals that are modulated in frequency and rhythm. While small animals vocalize at higher pitch than large ones due to the smaller size of their vocal apparatus, the rules governing vocalization rhythms throughout the animal kingdom remain unknown. Vocal rhythms serve as a natural information parser, and one possibility is that they are constrained by the neural rhythms of transmitter and receiver, known to be relatively conserved across species and independent of their size. In this study, we quantified acoustic rhythms across taxa and investigated their evolutionary history with regard to phylogeny and selective pressure. In 98 species from six classes, we tested the main factors likely to influence their communication rhythms: morphology, physiology, social complexity, mastication and detectability. Phylogenetic modeling did not confirm the influence of these species-specific factors, but rather point to a scenario where acoustic communication rhythms have been maintained around an optimum at around 3Hz in the biological (neuronal) delta range (1-4Hz) well before the mammals split. These results suggest that the rhythm of acoustic communication signals, unlike their pitch, has a universal neural determinant that has been conserved throughout evolution, allowing for intra- and cross-species signaling.

animal behavior and cognition↗