Did eating meat really make us human?
The diet plays an important role in everyday life animal, not only for your survival Y reproduction, but it can also condition habitat preferences, movement patterns, energy allocated to activity, competition, risk of predation, social interactions and communication, among others.
In the case of Humans, if we go back to our ancestors, feeding constituted an essential function in terms of habitat, migrations and interactions with the environment and its organisms.
The study now disproves the “meat made us human” hypothesis and casts doubt on the primacy of meat eating in early human evolution.
“Once early humans started eating meat, they likely ventured into environments where animals would have died naturally for them and encountered other predators more often, leading to increased competition and risk of predation. ”, exemplifies SINC Briana L. Pobiner, researcher in the Department of Anthropology at the Smithsonian Institution en EE UU.
Thus, the carnivorous diet could also have had a great impact on the evolution of the human behavior Y anatomical features. Not having sharp teeth like predators to tear meat and access the marrow of prey, humans began to use the stone industry through stone tools.
In fact, the appearance of Standing man, about two million years ago, seemed to have been the turning point in the evolution of the human diet: the increase in animal consumption could have driven a larger size of brain and body and a reorganization of the intestine. These traits were maintained in Homo sapiens.
However, a new international study, published in the journal PNAS, now refute this hypothesis that “meat made us human” and questions the primacy of meat eating in early human evolution. Until now, the studies that supported the importance of animal consumption were based on the increase in paleoanthropological evidence with the appearance of the H. erectus.
1.5 million year old fossil bones with cut marks from Koobi Fora, Kenya. / Briana Pobiner
Biased analysis of fossils
But for a dietary change generalized leads to the acquisition of key characteristics in this hominin species should be persistent in the zooarchaeological record over time. And this can only be convincingly demonstrated by large-scale analysis, beyond a single site or location.
“Most of the studies on fossil bones with butchery marks are limited to examining the evidence from a single deposit, or even from a single layer of a deposit”, Pobiner, co-author of the study, tells SINC.
The study thus undermines the idea that eating large amounts of meat drove the evolutionary changes of our earliest ancestors.
W. Andrew Barr of The George Washington University
To have a broader view of the first evidence of our meat consumption, the team synthesized all the evidence published so far on this type of remains in nine main areas of research in east africa, including 59 deposit levels, from 2.6 million years ago to 1.2 million years ago.
“We compared the patterns of fossil bones with butchery marks to the amount of fossil evidence in general, to see if this was really a sign of increased meat eating, or if it was just that digging up more fossils causes you are more likely to find them with butcher marks. It turns out that it was the latter”, confirms the expert.
The researchers found that, when variation in sampling effort over time is accounted for, there is no sustained increase in the relative amount of meat consumption trials following the onset of H. erectus.
The results suggest, therefore, that the findings on the carnivorous diet would be the reflection of a intensive sampling, rather than changes as such in human behavior. The study thus undermines the idea that “eating large amounts of meat drove the evolutionary changes of our earliest ancestors,” he stresses. W. Andrew Barr, Associate Professor of Anthropology at George Washington University, USA, and lead author of the study.
Meat consumption then and now
Despite this, meat consumption has played an important role in our evolutionary history. “We have evidence that some early human species, such as the neanderthals, they ate significant amounts of meat,” says Pobiner.
Currently, culture (and economy) are the great engine of variety in the amount of meat that people consume in different societies
Briana Pobiner, Smithsonian Institution
Currently, the researcher – who has been excavating and studying fossils marked by cuts for 20 years – stresses that “culture (and economy) are the great engine of the variety in the amount of meat that people consume in different societies” .
“I think this study and its conclusions are of interest not only to the paleoanthropological community, but to everyone who currently bases their dietary decisions on some version of this meat-eating narrative,” says Barr.
According to the researchers, large data sets are necessary to understand the broad patterns of our evolutionary history. “We need more fossil samples from unsampled time periods, such as before 2 million years ago, in order to test the importance of meat eating during those earlier time periods,” Pobiner concludes.
W. Andrew Barr et al. “No sustained increase in zooarchaeological evidence for carnivory after the appearance of Standing man” PNAS
Rights: Creative Commons.