No sustained increase in zooarchaeological evidence for carnivory after the appearance ofHomo erectus

Abstract

The appearance of Homo erectus shortly after 2.0 Ma is widely considered a turning point in human dietary evolution, with increased consumption of animal tissues driving the evolution of larger brain and body size and a reorganization of the gut. An increase in the size and number of zooarchaeological assemblages after the appearance of H. erectus is often offered as a central piece of archaeological evidence for increased carnivory in this species, but this characterization has yet to be subject to detailed scrutiny. Any widespread dietary shift leading to the acquisition of key traits in H. erectus should be persistent in the zooarchaeological record through time and can only be convincingly demonstrated by a broad-scale analysis that transcends individual sites or localities. Here, we present a quantitative synthesis of the zooarchaeological record of eastern Africa from 2.6 to 1.2 Ma. We show that several proxies for the prevalence of hominin carnivory are all strongly related to how well the fossil record has been sampled, which constrains the zooarchaeological visibility of hominin carnivory. When correcting for sampling effort, there is no sustained increase in the amount of evidence for hominin carnivory between 2.6 and 1.2 Ma. Our observations undercut evolutionary narratives linking anatomical and behavioral traits to increased meat consumption in H. erectus, suggesting that other factors are likely responsible for the appearance of its human-like traits.

Insights on the Early Pleistocene Hominin Population of the Guadix-Baza Depression (SE Spain) and a Review on the Ecology of the First Peopling of Europe

“…This explains why the consumption of large ungulates was a fundamental component of the high-quality diet that allowed the evolutionary transformations that led to the genus Homo (e.g., reduction of postcanine teeth, brain expansion, enhanced cooperation with non-kin, and shorter interbirth intervals). For this reason, the tool-use/meat-eating package has been considered as inherently linked to the definition of Homo (Jiménez-Arenas et al, 2014;Thompson et al, 2019;Pobiner, 2020; however, for a recent criticism of the narrative that links the anatomical and behavioral traits of H. erectus to an increase in meat eating, see Barr et al, 2022).…”

“…bone marrow, brains and meat (Ben-Dor et al, 2021). Therefore, the trophic level of Homo probably evolved from a low base to a high carnivorous position during the Pleistocene, beginning with H. habilis as a scavenger and peaking in H. erectus as a hunter (Ben-Dor et al, 2021; but see Barr et al (2022)).…”

Vertebrate Predation and Tool-Aided Capture of Prey by Savannah Wild Capuchin Monkeys (Sapajus libidinosus)

“…However, the fact that it is so common in this population of capuchins but not others also presents a case of a behavioral tradition in these groups (Haslam et ), adding to this suitability. Hunting using tools was crucial in human evolution (although the accepted evidence of increased carnivory after the appearance of Homo erectus has been recently questioned, see Barr et al 2022), and studying primates that present similar traits evolved independently is a promising way to understand better the evolutionary factors involved.…”

“…Predation on large vertebrate prey was an important behavior present during human evolution (Butynski 1982; Thompson et al 2019). Hunting for the meat of larger animals gave an energetic input that allowed the maintenance of larger brains, enhanced cooperation, prolonged childhood, and shorter female interbirth intervals, among other human characteristics that were only possible by the energy obtained from consuming meat (Thompson et al 2019; however, see Barr et al 2022 for a critical view of carnivory link to human evolution). Other primates also hunt and consume vertebrates opportunistically.…”

Using machine learning on new feature sets extracted from 3D models of broken animal bones to classify fragments according to break agent

“…These long-standing debates are founded on the premise that the use of large animal food resources was a highly influential factor in our evolution. Conversely, Barr, Pobiner, Rowan, Du, and Faith (2022) downplayed the role of meat consumption altogether, stating that there is no evidence for increased carnivory after the appearance of Homo erectus. Clearly, debates continue on the extent to which large animal food resources informed our evolutionary past.…”