How did early human ancestors secure their sustenance? This might seem like an obvious query, yet it holds significant weight for comprehending our evolutionary journey. Specifically, investigating how early human species established their ecological niche—what they consumed and the methods they employed to acquire food—can unlock insights into the development of our brains and the subsequent social transformations.
Current research now suggests that our forerunners were simultaneously adept scavengers and accomplished gatherers, capable of obtaining, processing, and sharing animal resources across diverse habitats. The findings of this new study were published in the journal PNAS.
Animal carcasses represented a crucial source of calories for ancient humans, but how exactly did they procure these resources? For decades, scientists have debated whether our earliest ancestors predominantly scavenged or hunted. Initial theories favored the idea that humans were opportunistic scavengers, whereas later views leaned toward them being confrontational hunters or scavengers.
In this latest investigation, scientists examined animal fossils dating back 1.6 million years, unearthed at the renowned archaeological site known as the Koobi Fora Formation in northern Kenya. The research team determined that early human ancestors didn’t merely consume meat they found; instead, they dismembered carcasses, selectively transported specific parts, and systematically processed them.
The Koobi Fora Formation is situated in the Turkana Basin and contains one of Africa’s longest, most continuous sequences of Palaeo-Pleistocene deposits—an era spanning the Pliocene (roughly 5.3 to 2.6 million years ago) and the Pleistocene (approximately 2.6 million to 11,700 years ago). This location yields an abundant fossil record, perfectly suited for assessing shifts in early hominin behavior.
By analyzing over 1,000 fossilized bones recovered from the site, predominantly belonging to antelopes and other herbivores, researchers identified scratches and pitting marks on some specimens. These microscopic traces help distinguish damage inflicted by stone tools from that caused by predator teeth.
The researchers observed a low incidence of carnivore tooth marks across all the archaeological assemblages they studied. This implies that hominins played a substantial role in the fate of these animals. Furthermore, the concentration of cut and impact marks along the shafts of long bones—such as the mid-sections of leg bones—points to the systematic removal of muscle tissue and marrow.
Given that limb bones were disproportionately represented in these finds compared to other skeletal elements, the scientists propose that hominins favored body parts easily carried to safer locations for consumption. If they had fed at the kill site, complete skeletons would likely have been recovered, which was not the case.
“The predominance of limbs in the assemblage aligns with patterns of selective transport, suggesting that early members of the genus Homo prioritized processing high-yield carcass portions that necessitated minimal logistical effort,” the researchers explain in their paper.
All the archaeological evidence cited in this study originated from areas that were once wetlands. These environments provided consistent access to water and a wealth of aquatic flora, which, in turn, drew in herbivores. The reappearance of these findings across multiple habitat types suggests that this ecological strategy was not unique to a single hominin group but represented a broader, opportunity-based foraging strategy.
“These findings address long-standing questions regarding early Homo evolution, including how this lineage adapted to environmental variability, expanded into new territories, and whether the emergence of Homo erectus coincided with shifts in meat consumption or cooperative behaviors such as food sharing,” the researchers elaborate.
It appears that natural selection favored traits enabling populations to persist despite fluctuating environmental conditions, rather than traits promoting specialization within one specific environment.
“The behavioral pattern documented here provides concrete archaeological validation for this adaptive flexibility, demonstrating that a consistent carcass exploitation strategy was maintained across environmental heterogeneity and shifting competitive regimes,” the authors add. “Flexibility, in this context, refers to the wide array of environmental conditions under which this strategy could be deployed, rather than frequent shifts in foraging methods.”
Ultimately, the research indicates that meat processing and consumption were characteristic features of early human lifestyles, not exclusive to a single species like Homo erectus, as previously hypothesized. It also demonstrates that food sharing offered evolutionary advantages as a buffer against short-term fluctuations in meat availability. This meant no individual faced the risk of starvation or undue danger attempting to secure a larger individual portion.
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