The Ancestral Human Diet | Peter Ungar | TEDxDicksonStreet

this is what the

ancestral

human

diet

was like my name is

peter

unger I am a paleoanthropologist at the University of Arkansas I study

human

evolution and more specifically I reconstruct the

diet

s of our ancient ancestors people often ask me what the

ancestral

or natural human diet is or was and this It is a topic that has been debated for literally thousands of years, often raised as a question of the morality of eating meat. The lion has no choice, but we take as an example Pythagoras, not only the patron saint of high school triangular formulas, but also of ethical standards. vegetarianism and once wrote: "How bad it is that meat is made of meat!" He intended for us to eat animals, why did he make them with meat?

She's actually right, whether you agree with it or not. When we look at fossil sites like Olduvai Gorge in Tanzania, we see bones eroding from the soil covered by the tell tale. Scars from butcher cuts everywhere, there is very little doubt that our ancestors ate meat millions of years ago, but we also have places like Oh Hollow: on the Sea of ​​Galilee, in Israel, we have the wild ancestors of the wheat, barley and rye. Eating these ten thousand years before the origins of agriculture, during the peak of the last great Ice Age, there is also nothing unnatural about gluten and, in fact, when we look at Neanderthal teeth, we find them buried deep in Tartarus , in those teeth, in those teeth, the small ones. barley starch granules, so all this despite the widespread call today to reduce carbohydrates and this brings us directly to the heart of the matter: paleolithic diets today, the people who advocate these diets argue that we should eat more how our ancestors ate.

Since you wouldn't put regular fuel in a car built for diesel, you shouldn't be eating foods we haven't evolved to eat, so whether you're stuffing your face or filling up your tank, the wrong fuel can wreak havoc. about the system and according to these diet gurus, many of the chronic-degenerative diseases we face today, not only obesity, but also heart disease, type 2 diabetes, various forms of cancer, may be related to a mismatch between what we eat and what our ancestors evolved to eat. Are these Paleo diet gurus telling us to eat well? We should get our proteins from grass-fed cows and fish.

We should get our carbohydrates from non-starchy vegetables and fruits, but we should need breads and legumes. Dairy potatoes. Any type of highly processed food. or refined foods, no longer exist. I am not a dietician and cannot speak authoritatively about the nutritional costs and benefits of any of these types of diets, but I can speak to the Paleo underpinnings of at least one of these diets. The human fossil record. Dating back about seven million years, we have thousands of fossils today representing this time period. We can divide these fossils into approximately four groups. I would call the first group RT Pittacus and his friends, these hominids, as they are called, live between seven and four years. million and a half years they lived mainly in the trees of what is now Africa they had not yet descended to the earth, then about four or two million years ago we have the next group that we can call Australopithecus now that Australopithecus had descended from the trees , which makes sense in light of the fact that savannahs are beginning to spread across the African continent, particularly in the eastern and southern parts, then, about two and a half million years ago, there was a fork in the evolutionary path In one direction, we have a group. called Paranthropus are close cousins, these hominids were extremely specialized, large and heavy skulls, thick jaws, powerful chewing muscles suitable for life in the open savannah and in the other direction we have our own ancestors, the biological genus Homo, where we have skulls weaker, smaller teeth but a brain grows over time, so how do we reconstruct the diets of these hominids well?

I look at your teeth, teeth are the most commonly preserved fossils, they are the hardest, they are the most durable and they are the only durable parts of the digestive system that preserve and actually come into contact with food during life, so if we can learn something about the diets of our ancestors by looking at their teeth, we can tell something about food preferences in the past, how do we get it right? We look at the sizes, shapes and structures of the teeth of living primates and try to relate them to their diets so that we can go back to the fossils, look at their teeth and infer the diet in this image, for example, we have three species of monkeys in the bottom, we have a languor in the middle and macaque and in the upper part we have a mangabey monkey the languor eats leaves the macaque soft fruits and the manga at least sometimes hard foods like nuts and bark and we can see these differences reflected in the shapes of its teeth for example the Langer has long sharp blades for cutting or slicing tough leaf material, the mangabey has flat and blunt enamelled teeth for crushing hard foods and then the CAC is somewhere in between now this may teach us something about what that our ancestors were able to eat, but not necessarily what they ate on a daily basis, for example, the mangabey at the top only eats hard foods a couple of months a year, usually when its preferred foods, soft, fleshy fruits simply are not available, however, they have to be able to eat these types of foods.

To survive the tough times then they have to have teeth capable of this, but how do we rebuild the diets of our ancestors on a daily basis? What do they eat regularly? Well, we use what I call food prints which are like footprints in the sand. The actual activities of living organisms and the food imprint that I look at is a so-called Dental Micron, where microscopic scratches and pits form on a tooth as a result of its use, so if you look at the image above you see a microscopic wear surface . of a capuchin monkey that eats hard foods like nuts and seeds is covered with holes or craters at the bottom we see the microscopic wear of a howler monkey that eats leaves its teeth are covered with long parallel scratches it turns out that the teeth of capuchin monkeys have bones because they crushed those hard foods, while the howler monkey's teeth are scratched because when their teeth slide together when cutting the abrasives and blades are dragged along the surface of the tooth causing those long parallel scratches that engineers now call The Upper surface is complex and the lower surface is simple because all the features on that lower surface are approximately the same size, shape, and orientation.

Okay, now let's take a look at our actual ancestors. We start with something like Ardipithecus that lived again for seven to four years. a million and a half years ago its teeth are quite conservative the enamel is reasonably thin it has ridges of moderate length the teeth are quite small it is more or less what you would expect from a red fruit eater, but when we come to Australopithecus and particularly the homo the teeth get bigger the enamel gets thicker their surfaces become flatter we see more and more specialization but when we get to homo the teeth get smaller the enamel gets thinner the ridges get shorter it's almost an inversion of trends, so when we look at this, along a timeline, we start with something that essentially looks like a berry eater in a closed forest and then, over time, from the early Australopithecus to the Australopithecus late and the harsh, abrasive Inter/anthropocentrism, but then this fork in the road about two and a half years. millions of years ago with our own ancestors the teeth get thinner the brains get bigger we start to see meat entering the record at least judging by the cut marks on the bones found next to these ancestors?

What do the food prints on this slide teach us? What we have is that we have three different types of hominids, we have the Australopithecus group in red, our own ancestors, Homo, in blue and the employer/anthropocentric indicates softer foods, higher value foods and what we immediately see is that Australopithecus had a fairly narrow range of foods. at least judging by this evidence, mostly mild, but when we get to the homo, the early homo, the first one on the left, and then particularly the later homo, the breadth of the diet seems to be increasing. Paranthropus is also interesting, the first species there has a fairly narrow range of diets much like Australopithecus, but the second species has a much wider range of diets, pretty much what you would expect from a manga, since sometimes It needs hard foods but sometimes eats softer foods, so when we separate this and start with a diet of our own ancestors we see a progressive broadening over time from early to late Australopithecus and then early to later Homo. and when we look at anthropocentric species with the same shape, teeth, skulls with the same shape but very different diets, one very narrow and the other very wide and what this tells me is that the shape of the teeth alone is not enough to predict diet;

There is more to the diet than the shapes of the teeth and this introduces the concept I call the biospheric buffet. I think of the biosphere, the part of our planet that supports life is a kind of giant buffet, the animals approach the sneeze guard with their plates in their hands and choose from whatever food is available to them at any given time in a certain place, yes, teeth are important, they are the utensils you have to eat but they are not enough to tell us at least their shapes what animals eat availability is key this explains why a chimpanzee in the forest eats forest food why a baboon or in this case a gelada monkey eats its resources from the savannah Yes, its teeth are important, but they are not enough and this is especially relevant when thinking about human evolution because climatologists teach us that the environment varied dramatically over time. time and oscillates from cold and dry to warm and wet during the course of human evolution. and with those changes and climate come changes in the availability of different types of food, there is a trend over time to become colder and drier through human evolution, which explains the expansion of savannahs in the east and the southern Africa, but there is more than that, there is also an increase in breadth. of the changes in the intensity of the changes and many people may have even argued that it is that type of capacity for change in the environment that variation that exists variability in the environment that has made us human is selected for our flexibility our versatility so We have to go back to the original question: what was the ancestral human diet?

Well, in light of what we've learned, the question itself doesn't really make much sense. our lineage was a work in progress. Our diets varied over time and space with the changes. availability of different types of food and, in fact, this is what allowed our ancestors to find something to eat no matter where they roamed, whether it was in the High Arctic, where almost all their food consisted of marine mammals and fish, or at the equator, where they could get 70% of their calories from sugary melons and starchy roots, in a sense our evolution has prepared us for a versatility that has allowed us to conquer the world, so in the end, when I think about evolution of the human diet, when I think about Paleolithic diets I don't think about planning our menu for today I think about the verse the flexibility for which our evolution has prepared us we can eat the good we can eat the bad and we can eat the ugly this versatility is for me what defines us as humans and is the key to our evolutionary success, thank you, you.