Early Pleistocene faunivorous hominins were not kleptoparasitic, and this impacted the evolution of human anatomy and socio-ecology

Abstract

Humans are unique in their diet, physiology and socio-reproductive behavior compared to other primates. They are also unique in the ubiquitous adaptation to all biomes and habitats. From an evolutionary perspective, these trends seem to have started about two million years ago, coinciding with the emergence of encephalization, the reduction of the dental apparatus, the adoption of a fully terrestrial lifestyle, resulting in the emergence of the modern anatomical bauplan, the focalization of certain activities in the landscape, the use of stone tools, and the exit from Africa. It is in this period that clear taphonomic evidence of a switch in diet with respect to Pliocene hominins occurred, with the adoption of carnivory. Until now, the degree of carnivorism in early humans remained controversial. A persistent hypothesis is that hominins acquired meat irregularly (potentially as fallback food) and opportunistically through klepto-foraging. Here, we test this hypothesis and show, in contrast, that the butchery practices of early Pleistocene hominins (unveiled through systematic study of the patterning and intensity of cut marks on their prey) could not have resulted from having frequent secondary access to carcasses. We provide evidence of hominin primary access to animal resources and emphasize the role that meat played in their diets, their ecology and their anatomical evolution, ultimately resulting in the ecologically unrestricted terrestrial adaptation of our species. This has major implications to the evolution of human physiology and potentially for the evolution of the human brain.

Sabertooth carcass consumption behavior and the dynamics of Pleistocene large carnivoran guilds

“…Scavengers hoping for a more complete menu of foods would need to drive these big cats from their kills early in the feeding sequence. Early Pleistocene stone-tool-using hominins likely could have gained quick access to the kills of homotherines and other sabertooths via confrontational scavenging, although evidence is mounting that they were successful hunters in their own right well before their incremental ascent to apex predator status in the middle Pleistocene 109 – 112 . Local ecological circumstances no doubt dictated how, and how often, these kills were encountered and utilized by hominins and other consumers.…”

A case of hominin scavenging 1.84 million years ago from Olduvai Gorge (Tanzania)

“…47 The anatomical distribution is only coincident with experimental butchery of complete animals, and not with experimentally butchered carcasses obtained from felid kills with different degrees of intensity in their consumption. 47 The overall picture reinforces interpretations of early access of hominins to most of the carcasses represented at those sites. The existence in all of these sites of evisceration cut marks on the ventral sides of ribs and vertebrae further shows that carnivores did not precede hominins in their access to those carcasses, 21,30,39,48 since viscerae are the first parts of carcasses consumed by felids.…”

“…A wealth of taphonomic information created by hominins themselves is contained in the frequency and anatomical distribution of cut marks created during butchery. Recently, a comparative 3D anatomical distribution of cut marks at DS and the other two pene‐contemporaneous sites of FLK Zinj and PTK, occurring on the same paleolandscape, has shown an interesting patterning in how cutmarks are anatomically distributed in the three assemblages 47 . The anatomical distribution is only coincident with experimental butchery of complete animals, and not with experimentally butchered carcasses obtained from felid kills with different degrees of intensity in their consumption 47 .…”

“…Recently, a comparative 3D anatomical distribution of cut marks at DS and the other two pene‐contemporaneous sites of FLK Zinj and PTK, occurring on the same paleolandscape, has shown an interesting patterning in how cutmarks are anatomically distributed in the three assemblages 47 . The anatomical distribution is only coincident with experimental butchery of complete animals, and not with experimentally butchered carcasses obtained from felid kills with different degrees of intensity in their consumption 47 . The overall picture reinforces interpretations of early access of hominins to most of the carcasses represented at those sites.…”

“…In contrast, the most parsimonious way to reconcile taphonomic evidence of cut, percussion, and tooth marks on the anthropogenic sites from Olduvai Bed I is the interpretation that hominins were focusing on bulk flesh exploitation 21,47,51 . Although this is suggestive of either hunting or confrontational scavenging, no direct evidence has been presented before to support either of them.…”