Kim Hugh John Shaw-Williams

Only our lineage has ever used trackways reading to find unseen and unheard targets. All other terrestrial animals, including our great ape cousins, use scent trails and airborne odors. Because trackways as natural signs have very different properties, they possess an information-rich narrative structure. There is good evidence we began to exploit conspecific trackways in our deep past, at first purely associatively, for safety and orienteering when foraging in vast featureless wetlands. Since our own old trackways were recognizable they were self-mirroring, triggering memories of what we had been up to in the past. Using them to find our way back to the band when temporarily lost or to re-find a resource-rich area discovered the day before enabled optimal foraging. Selection for daily reiteration of one’s own old trackways therefore triggered the evolution of what is distinctive about human cognition: the autobiographical or narrative (episodic) faculty for imaginative self-projection. This faculty enabled us to glean useful social information from the stories “told” by other band members’ old trackways, and created spin-off capacities for fast-track social learning. Resultant increases in socioecological complexity then created positive selective feedback loops for further entrenchment. Incrementally we became the ultra-social narrative-minded ape, capable of creating cumulative culture.

In this thesis I present a new paradigm in human evolutionary theory: the relevance of track-ways reading (TWR) to the evolution of human cognition, culture and communication. Evidence is presented that strongly indicates hominins were exploiting conspecific track-ways 4 million years ago. For a non-olfactory ape that was a specialized forager in open, featureless wetland environments, they were the only viable natural signs to exploit for safety, orienteering, and recognizable social markers. Due to the unique cognitive demands of reading track-ways, as compared to scent-trails all other animals use to find each other and preferred prey species, social TWR triggered the evolution of a unique faculty for narrative elsewhere-and-when cognition in the hominin mind. Two million years later, this narrative faculty was entrenched enough to enable the rather sudden ‘explosion’ of co-operative Oldowan Lithic Culture that began at 2.6mya. This cultural adaptation was a highly successful response to catastrophic environmental change. Thereafter selection for encephalization to increase neural capacity to store and co-operatively exploit socio-ecological knowledge gained from the hominin narrative faculty (via co-evolving, increasingly efficient modes of intentional communication) drove all further biological and cultural developments in the hominin trajectory towards H.sapiens and behavioural modernity.

The social trackways theory is centered on the remarkable 3.66 mya Laetoli Fossilized Trackways, for they incontrovertibly reveal our ancestors were already obligate bipeds with very human-like feet, and were intentionally stepping in other band members’ footprints to maintain safe footing. Trackways are unique among natural sign systems in possessing a depictive narratively generative structure, somewhat like the symbolic sign systems of gestural languages. Therefore, due to daily embodied reiteration of their own and other band member’s old footprints, both for bipedal safety and as recognizable wayfinding markers for socio-ecological navigation, incrementally our Mid-Pliocene ancestors began to acquire a cognitive capacity for episodic personal memories and episodic future simulations. They began mentally representing themselves as intentional agents continuously travelling from the past into the future. This spatially and temporally self-projecting awareness manifested itself as extra theory of mind and mental space-and-time-travel capacities, which increasingly enabled intentional or conscious, top-down executive adjustment of past behaviors for the sake of achieving better ways of doing things in the future. Future-directed behavioral and cultural adaptations began to increase fitness in all domains, thus creating powerful selective feedback for further entrenchment. Here we focus on overtly or consciously intentional exploratory wayfinding and transmission of elsewhere-and-when information, using pragmatic, discursive modes of communication, which enabled far more cooperative and efficient foraging practices. Selection for better communication thus led to intentional trail marking and the earliest emergence of more conventional/symbolic depictive and gestural “protolanguages.”