Evolution of primate protomusicality via locomotion

Abstract

Animals communicate acoustically to report location and identity to conspecifics. More complex patterning of calls can also function as displays to potential mates and as territorial advertisement. Music and song are terms often reserved only for humans and birds, but elements of both forms of acoustic display are also found in non-human primates. While theories on proximate functions abound, ultimate drivers of specific call structures are less well understood. We hypothesized that spatio-temporal precision in landing during perilous arboreal locomotion favored the evolution of musical calling in early primates—vastly preceding the origin of more music-like behavior in hominoids and subsequent emergence of music in later hominids. We test this locomotion-based hypothesis on the origins of proto-musicality using spectrographic depictions of vocal repertoires of modern day primates and corresponding estimates of locomotor activity. Phylogenetically controlled regression analysis of 54 primate species reveals that arboreal locomotion and monogamy are robust influences on complex calling patterns while controlling for other socioecological variables. Given that these findings rest primarily upon a handful of deep branching points in the primate tree, we conclude that this coevolution likely occurred very slowly, occupying on the order of tens of millions of years.LicenseAttribution-NoDerivatives 4.0 International (CC BY-ND 4.0)

The origins of musicality in the motion of primates

“…Possibly analogous pattern‐matching also occurs between disparate visual inputs for modulating rectus muscle control over eye position in actuating stereoscopic vision. In primates, this could manifest as part of hand‐eye coordination for grasp placement adjustments (Schruth et al, 2020), for landing clawless grasps on substrate with velocity (e.g. while completing aerial‐spectrum locomotor bouts).…”

“…Swinging was also composite with armswing and other suspensory modes. Full details of the data collection procedure are available elsewhere (Schruth, 2021b) and the full data‐set can also be found online (Schruth, 2019a).…”