Hunter-gatherers had a taste for cereals

These days, most of us are fed by farming. Previously, though, we lived a very different lifestyle: one dominated by hunting and gathering. How that transition to agriculture and urban living happened though isn’t well understood. Scientists have long suspected that early hunter gatherer communities already had a taste for many of the plant species they subsequently began to farm, but the evidence for this was limited to sites only in Greece. Now, speaking with Chris Smith, Emanuela Cristiani, from the University of Rome Sapienza, explains how she has found evidence - from tooth tartar and early tools - for precisely this transition also happening in the same way in parts of what is now Serbia and Romania…

Emanuela - There is a big unknown, which is whether foragers used plant foods in their diet before the arrival of farmers; before the introduction of agriculture.

Chris - When did farming actually get started?

Emanuela - In this region, it arrived around 8,500 years ago.

Chris - Before that time, what did we think life consisted of?

Emanuela - The diet and the subsistence was mainly focused on hunting and fishing and a very limited gathering of possible plans.

Chris - Is the evidence strong for that? Is that just our inference because we can see a line in the timeline where people start to gathering communities that are a bit more permanent and that goes with agriculture, or do we actually have rock solid evidence that we can point to, to say 'that's how people were living, and this is what they were probably eating'?

Emanuela - At that time, before agricultural societies were definitely more mobile. We are thinking that they were possibly hunting and gathering more than living in villages. But there is another problem here for the reconstruction of diet is that the evidence we get in archaeology is stronger for bones than for organic remains like seeds or plant remains, meaning there is a preservation problem.

Chris - Is there a way around that?

Emanuela - Yes, absolutely. We have to work with evidence that is in a way indirect. One is the actual use and consumption of plant foods that can leave the residues in the mouth, on the teeth. The other is the study of technology that is used for processing the plants and extract the nutrients from the plants.

Chris - When you say "residues in the mouth", is this plaque on teeth?

Emanuela - Yes. The plaque, the dental tartar which is a sort of mineralised plaque can survive for millennia on ancient teeth. We in archaeology consider it as a special treasure trove, because the plaque can trap particles of foods, but also can trap bacteria, particles of the environment that we inhale when we breathe, or when we use the mouth as a third hand.

Chris - Where did you get plaque to look at? Who have you been studying?

Emanuela - We have been working on a huge number of individuals that were buried in a number of sites in the Dream George in the central Balkans, which is a region where we have important documentation of hunter-gatherer communities in the period before the arrival of agriculture.

Chris - And so this is people from pre-8,000ish years ago.

Emanuela - Yes. People from 11,500 to around 8,500 years ago.years ago to the arrival of agriculture.

Chris - And the obvious question then is, when you look at what these people were eating based on what's trapped in their teeth, what do you find?

Emanuela - Starches, which is the most important energy reserving in plants. In particular, we found granules of this starch, which is the form in which the starch is preserved in specific organs of the plants, like roots or seeds. Those are the parts that we are interested in when we want to eat plant foods. The types of starches we found in the dental calculus, but also on the stone surfaces were typical of certain species of wild cereals and also other types of plants like oats.

Chris - This would tell us then that these hunter-gatherers definitely were gathering, and certainly a part of their diet comprised of cereal crops that were wild grown, presumably. Is this a stepping stone in some respects then, because agriculture didn't just suddenly spring up. Did people, do you think, become familiarised with these plants and then begin to domesticate them? What you are seeing here is that stepping stone, that early prelude to familiarity with the crops that we were going to start farming later.

Emanuela - Yes, exactly. The findings we found meant that these foragers in this region have been sharing knowledge they knew about this plant species for quite a long time, as we found some of these starches, even in individuals dated to 11,500 years ago. It means that at least for 4 millennia before the arrival of agriculture, these people knew and used these pieces in their diet. This also meant to us that this familiarity might have eased. It might have created a sort of taste palatability familiarity with a sweetness of, for example, the grains and eased the acceptance of these plants once they were brought in a domesticated form by the farmers.

Chris - And was it just the practice of farming that was then embraced? Or was it that prior botanical knowledge of those plants that they were also incorporating? Was it both? As in, they became familiar with eating those plants, they became familiar with the plants themselves, and then they domesticated them, or did someone else come along with the know-how and say, 'this is how you do it. This is what you grow.'?

Emanuela - I think that what was brought by was the knowledge of cultivating probably the seed, but not the familiarity and the taste of them, which was known for quite a long time.

Chris - Do your results broadly agree then with what we thought was the process through which farming was embraced in this area and more broadly, or are there any areas which don't quite line up and which might therefore be interesting avenues to pursue?

Emanuela - The results absolutely agreed with what was embraced for the area, for the arrival of agriculture, but also for what the connection between the farmers and the foragers were in this area based on other evidence. For example, we found on dental calculus, evidence that already the latest hunter-gatherers in this region were consuming domesticated plants and domesticated cereals at the end of their life as hunter-gatherers. This means that they probably exchanged domesticated species, domesticated grains with other communities that were farming communities living around 8,500 years ago in the region. In a way there was familiarity with the plant foods, but the results shed light on the way this change in our history happened.