 Yeah, Dr. Miki Bindor now. He says, right here. So first of all, I would like to thank Aaron for inviting me and to give me the chance to give this talk and to be present in this wonderful meeting with wonderful people. I started my presentations in Boston in 2012, where I presented a paper that was just published called Men the Fat Hunter. And this paper was based on a finding in a site called Kesson Cave, 15 minutes drive from Tel Aviv, where teeth of a human that was not supposed to be there were found. So these are teeth of a hominin that is very similar to Homo sapiens. At that time, Homo sapiens was believed to have evolved in Africa 200,000 years ago. And this site is 400,000 years ago. So later it was discovered that Homo sapiens actually appeared 300,000 years ago. But this is still 100,000 years ago before the appearance of Homo sapiens in Africa. You find a hominin that's very similar to Homo sapiens in the Levant, in Israel and its neighbor area. And that needed an explanation, and I had one. So the explanation was, and it was associated, this 400,000 years ago, elephants disappeared from that area, from the Levant. And so if you tie the two phenomena together, you can say that maybe because of the extinction of the elephant, which was the main source of food for the previous hominin, Homo erectus that was there, because it was found in all the sites of Homo erectus in this area, it was found the elephant bones. So if this human had to hunt now smaller animals, of course it takes more energy to hunt smaller animals than large animals. So you hunt once, and then you can leave off an elephant for a month or two, but if you're on smaller animals, you can only leave for a week, let's say, so you have to hunt many more animals. So energetically you have a problem. And so in order to overcome this problem, you have to become more efficient in hunting smaller animals, and one way to do that is to do tracking, because if you track an animal, you are not dependent on randomly encountering that animal in the environment. And tracking demands a lot of brain power. You have to remember, you have to know a lot about the nature, species, how they behave, et cetera, et cetera, in order to do tracking. And that you need to make decisions, very quick decisions under pressure when you do tracking. So you need a large brain, that was the explanation. There are other things that homo sapiens have, morphologically, et cetera, that can also be attributed to the need to be more efficient energetically in hunting smaller animals. But I won't go into it. So everything is based. Why humans were dependent on large animals? The idea is that since humans can metabolize protein into energy only to about 35% of the energetic requirements, then they have to actually get 65% of their energy from either carbohydrates or fat. So if they have on the left-hand side, if they can obtain 50% of the energy from plants in the form of carbohydrates, they only need to get 15% in animal fat to complete the deal. And 15% animal fat, if you now just look at the animal itself, that 15% of the total becomes 30% of the animal. So if you have animal with 30% fat, you can get 15% of the total. Just have to believe me, it's a little difficult. And finding animals with 30% is no real problem. Most animals have 30% fat. Although during dry seasons, the fat content go down, so it becomes a problem. But normally, the database that I had showed that smaller animals have 30%. However, if you can only get 30% of the total energy from plants, you're in trouble. Because then you need to get 35% of the total energy that you need from animal fat. And if you take just the animal, it becomes 50% of the animal calories. So you need animals that contain 50% fat, and there are not many like that, and they are all large animals. So really, it depends on the availability of plants. You may be dependent on large animals. And that was the idea, that large animal disappeared. You became dependent on them for fat, so you had to get fat from smaller animals. You could only exploit part of the animal sometimes, et cetera, et cetera, so energetic pressure on humans. That was alleviated by evolution. I'll skip that one. So a crucial question is, how much plant food was available? And this was the subject of my next presentation in Atlanta in 2013, that unfortunately was taped, but never went somewhere in the sky. So anyway, I had to go not to archaeology. Though I studied archaeology, actually the answer of how much plant human aid is not in archaeology, because plant matter don't preserve. So you come to an archaeological site, prehistoric archaeological site. Mostly what you find is the stones and bones. And it doesn't really tell you anything about the level of plant. So let's start to call it trophic level. So the higher the trophic level, the higher the animal portion of the diet. So you can't say what the trophic level was relying on archaeological. So I took clues from other areas, scientific areas, and took out the long story short because I don't have time. The conclusion was that we had the highly carnivorous diet during the Paleolithic. The next presentation, which was five years later. In the meantime, I managed to do a PhD, was given in Bozeman, Montana. And actually, it was a continuation of that same theme of looking for how much plant, or what was the trophic level. Although at that time, I also dealt with the curse, I would call it, of ethnography on trying to reconstruct the trophic level. So if you ask any paleoanthropologists today, most of them actually, and not maybe all of them, they will tell you that human were very flexible. Wherever the plants were available, they ate plants. And in the north, they ate more animal, and there was no problem. During the Paleolithic. And by the way, Lorenco then had a lot to do with it because that was his conclusion. But my argument is that recent hunter-gatherers are a bad, bad model for Paleolithic hunter-gatherers. And for two reasons. One is the technology. So recent hunter-gatherers use dogs. They use bows and arrows. Both of these technologies actually only were acquired during the last 2% of prehistory. So they did not exist for most of the prehistory. Both of them help you hunt smaller animals. Hadza, which is serving as a model for many, many paper, they actually use metal for about 500 years already. Have been using metal for containers and for arrow tips. So technology-wise, they're a bad model. And the environment is completely different. We cannot even start to imagine the difference between the environment in the Paleolithic and today. So this top picture is the Ngorongoro crater. And you see that there's very little vegetation. Most of it is grasses and many, many animals. And this is the environment in which human evolved. At the bottom is a picture that I took two weeks ago when I visited the hadza. And the landscape is completely different. There's no room for small animals. There's no grass. And whatever grass there is, it's taken by cows that neighbor herders bring into the hadza territory. So of course the hadza, on the other hand, you see a lot of vegetation which provides plant food. They go around. I went with them. They go around and they pick berries. Now these berries are nothing like what we eat today. But that's how they feed. They feed on berries and they feed on other fruits, roots. But so in any case, we published a paper at 2020 and sort of summarizing why the ethnographic record is a bad model for the Paleolithic. And then a few months ago, we published another paper. And this time together was a reference of Toli that some of you may know. And he was in charge of the biological side of it. We're really summarizing the findings regarding the trophic level of humans. With the conclusion that didn't change is that Homo genus, so Homo sapiens, Homo erectus before it, were actually hypercarnival during most of the Paleolithic, only starting to eat more plants towards the end of the Paleolithic. So the last 2% of the Paleolithic. And we also found, using the same evidence, that humans were adapted to hunt larger animals, so specialized in larger animals. One example I can give is the acidity. So we have very high acidity compared to other animals. We have actually the acidity of scavengers. So even higher acidities and carnivores. And the only explanation I could come up with is that when we hunt, we are hunting differently. We bring the prey into our place. And we protect it, and we sit on it. So we sit on it for a week, two weeks. In the meantime, it rots. And we need the protection against pathogens that the acidity provides. So evidence like that shows us that we are adapted to specialize in large animals. I'll skip that one too. So let's see what happened to large animals during the Paleolithic. So this is, we did this work on the record, the final record of Israel and the neighbors. So very close, and there's a good archaeology there. So took about 70 or so sites, archaeological sites, calculate the average size of the prey. And as you can see, it goes down and down and down and down. Until we end up with the gazelle as the dominant animal, 25 kilos. And then even younger gazelles that don't have any fat. So really like people become desperate at the end. So this is in the Levant. In Africa, 2018, on science, Felissa Smith and their group came up with an interesting, even deeper view of what happened to large animals. They showed that animals became larger and larger and larger over 65 million years since the extinction of the dinosaurs. And they reached about 500 kilo average. This is terrestrial mammals. 500 kilo average about two and a half million years ago. And today it's about 10 kilos. So drastic decline that happened during the reign of human as a caretaker of the environment. And I did some studies, some checks myself on certain situation worldwide. These are just two. And this is Africa on the left side, Africa 300,000 years ago. And on the right side is Europe 50,000 years ago. Both places you see a decline in prey size as homo sapiens appear. So in any case, we have quite a good proof, let's say, or strengthening the hypothesis that there was a prey size decline. They didn't start only in the late quaternary, mega fauna extinction, which is agreed upon. Well, it started about 50,000 years ago, but it started much, much more earlier. So that led us to tie the two things. We were carnivores, we were specializing large prey, prey size declined. So this can explain, must explain a lot of the phenomena that happened in prey history. So we published this paper in quaternary. It's not the best journal, okay? It's a new, I think it's quite new journal, but we could not, we sent it to nature. They said that there's no advance in science in our paper, so they rejected it. But anyway, we published it. And before I continue, I just want to say something about a unifying hypothesis, okay? We are here actually because of a unifying hypothesis, because the mismatch theory or the evolutionary actually explain many phenomena. Just one cause explained many phenomena. So you have a unifying hypothesis. So it's interesting to look into unifying hypothesis. So two examples. One on the left is a guy by the name of Emmanuel Velikovsky who was a psychiatrist and psychologist and wrote a book in the 40s called World in Collision and managed to sell quite a lot of copies. And his claim was that cosmic collisions explain biblical phenomena. So this is, of course, complete baloney. The cosmic collision didn't happen and the biblical phenomena, in my opinion, didn't happen either. So it's complete baloney. On the right hand side, you have Alfred Wegener whose name is not so familiar, but it should be, who was one of the first people to come up with the tectonic plate movement as explaining geological events. By the time he was vindicated at the beginning of the 60s, he was dead for 40 years, unfortunately. So you have, you can put all the hypotheses on this scale, on the right side, you have unanimously accepted the hypotheses. On the left side, you have unanimously rejected hypotheses. And in the middle, you have a soup of all hundreds of hypotheses that are moving left and right and some of them are not moving because people ignore them. But if you look into them, now, I didn't do it, but it's my belief is that you'll find very few unifying hypotheses and why is that? First of all, it's very difficult to come up with it. Because you need one source to explain many things. It's much easier to explain one thing with one thing. So Kicher, who is a philosopher of science, says that to explain is to fit the phenomena into unified pictures insofar as we can. So the more unified, the more phenomena you explain, the better the hypothesis as far as he's concerned. Another approach is this Karl Popper, where he says that better hypotheses are the more refutable ones. So there's no more refutable hypotheses than unifying hypotheses because you have many areas that can be attacked, okay? So it's a better from Karl Popper point of view as well. And another argument, I would say, is that the association of one factor with many phenomena strengthens the causality. So it's always a problem because we only talk about associations and then we can explain them mechanically. But the association will always tell associations and the causality, I think, is the probability of causality is improved when you have one that explains many phenomena. And the last one is maybe unique a little bit to my hypothesis here is the new unidirectionality. As I will show you, a lot of the phenomena in the prehistory are unidirectional, like the brain size increase, okay? It increased and increased and increased. In the late stage it declined a little bit, but over two million years it decreased. And you have an explanation by something that also has directional. So the pre-declined is also directional. So if you have many phenomena that are directional, explained by something directional, it's a little bit like those response in pharmacology. So it strengthens the causality of that. Another, some other criteria that scientists use to judge a hypothesis is simple, like oxomborazole, unified, explanatory, beautiful, elegant, harmonious, et cetera, et cetera. I leave you to judge whether that is applicable here. So one example of directionality that is not so obvious, and actually nobody wrote about it before, is the changing of cultures. So the first culture that we see is called Aldewan, and this is associated with the homo-habilis, very simple stone tools. It lasted about a million years, and the second culture is the Asciolian, and by the way it was worldwide. In other words, all over the world you could see the same culture, the same stone tools. Asciolian was also worldwide and lasted for about a million and a half associated with homo erectus, which by the way is my favorite species. And then pre-sized decline began in earnest, and 300,000 years ago, it appears another culture called the Musterian in Europe. It's called the Middle Stone Age in Africa. It's called Middle Paleolithic in other places, but basically it's the same culture. So it's worldwide, but it lasted only 250 years. The next cultures, which are all under the envelope of what's called Upper Paleolithic, already start to last tens of thousands of years, and then single thousands of years, and they become much, much more localized. So you have a directionality of shorter cultures and more localized cultures. So let's start with counting the phenomena that we can explain. So this is the cause, obtaining effect for smaller prey, and the need, it's not in here, but the need to compensate energetically, and this ties up with Stephanie's presentation yesterday, to cope up energetically with the extra load that smaller animals inflict on you when you get together. So brain we discussed the tracking, but there are other things as well, language. Language is a good one, because the unique property of language in comparison to talking with your face and hands is that you can convey, and this is not my idea, it's somebody else, you can convey events that took place somewhere else at a different time. So if you want to tell somebody that you saw an elephant in this and this lake yesterday morning, it's very difficult to do it with sign language. So you have to start to employ a language, but not only that. If you want to do good tracking, you need to accumulate a lot of information about nature, and you get to know, Hadza know hundreds of names for the birds in their territory or for the insects in their territory. They know the insects are nocturnal or they're active during the day, they know a lot. And just to accumulate this knowledge is to retain it, you need language, and to transfer it to the next generation, you need language. So language was important to cope and it makes you more energetically efficient when hunting smaller animal. A non sapient extinction, this is like, the good example is the neanderthal, on this extinction I did my PhD. Again, it's, he actually succumbed to the decline in prey size. He just couldn't cope with it energetically. I won't go into the details, but that's another, faunal extinction was helped by the need to obtain fat. So you need larger animals or you hunt prime adults, as we'll see a little bit later, or you exploit part of the animals. Sometimes you see signs that people just exploit the fatty parts of the animal. These three things actually make animals more suspicious or more vulnerable when climate change force them to make another pressure on them. So the need for more fat actually caused animals to be more vulnerable to extinction. A fire is another point, I think Stephanie, I don't remember if you'd made it, that we use instead of only the power of the food or the calorical value of the food, we use also external means to help us with the energy. So fire was the first one. We just collect some wood, not oil, but wood, and we use energy outside of our, so it becomes more effective. And so we can extract more energy from meat and from plant food as well. So fire can also be explained by the need to be more efficient energetically. Tools, tools go down in size. It's also a directional phenomenon. And it's also, you see that how they adapt it to hunt smaller and smaller animals. So you get stone tips that you put on a spear and then you get stone tips that you put on bow and arrow which go further after smaller animals. So again, a directional phenomenon. Behavior, like sharing others, I won't go into it, but again, can be explained, a lot of it, a lot of the changes. Can be explained as adaptation to hunt smaller animals. Homo sapiens, okay, we talked about the brain increase, size increase, but there are other morphological changes in Homo sapiens that allow them to run faster and all that stuff. It's also adaptation to hunting smaller animals. Culture changes, okay, we discard that. Large fauna, okay, just need to obtain fat can explain large fauna. In the archeological sites, we discussed that. Primedals, obtaining primedals is a crazy strategy for a predator because it's much easier to catch younger animals and it's much easier to catch older animals. So why would a predator choose to catch just part of the population already decreasing these chances of meeting an animal by maybe a half? And the only reason is fat, that I could come up with. Primedals are always fatter than other animals, than other ages, age groups. Apopoleolithic, okay, we started to discuss it, but the apopolitic major change that you can see is increasing the consumption of plants. So this is a reaction to the fat disappearance that happens when prey size start to decline. Dogs, dogs are a very good example of energetically effectively hunting smaller prey because they run for you, yeah? And by the way, you can feed dogs with the protein that you cannot metabolize yourself because lions and wolves can metabolize 80% of their energy from protein, no problem. And last but not least is the moving to agriculture where you get more energy from, if you need non-protein, okay, we need 65% to come from non-protein, when large animals completely disappear or very strongly disappear, then you sit down and you raise your own. So all of them, apart from this follow extinction, all of them can be explained energetically, okay? So I'm an economist, in economy you follow the money if you want to understand things. In biology, you follow energy. And this is why I think this explanation is neat. Also, the most of the phenomena are directional, okay? So this also, I think, strengthen the association. So with that I finish the introduction, but I want to say why it's actually relevant to us. So I think one point is very obvious is that fat and meat are natural to us and it's a food that we consume a lot of and we are adapted very nicely to it. The second one is maybe not so obvious, but still. The fact that we see a lot of behavior to catch fat, okay? To hunt fat, maybe the fat hunter, means that we were at the limit of the protein consumption. So for two million years, my belief is that we consumed 30, 35% of our diet from protein, so protein power to make it, make it. So we have about seven minutes for Q and A. If you line up at the two microphones for your questions and I'm going to take a chair's privilege and ask the first question. And I studied paleoanthropology as an undergraduate and a master's student, I had classes with Owen Lovejoy, I knew Emily Deans, I mean, Emily Deans, she's the next one, Dean Falk. That's one of those association errors. And other people, and Tim White, people like that and their students who are active in the paleoanthropological field right now, when they've heard your, I presume they've heard your, and read your papers or heard your talk. No, they haven't heard anything. Because I'd like to know what their response is. Okay, there was one site, a good sign site, that asked me who should they ask for response. And they, I've directed them to two Richard Potts, the Smithsonian, and John Hawks, I think it's Wisconsin. And both of them didn't like the theory. But the rejection was weak. You don't expect them to sit down and come up with a hundred reasons. So what they said is, first of all, that it's not proven that humans hunted large megafauna. Okay, okay, well, that's one. And the other thing they said is that there is, we don't know in detail what was the pace of brain extension. And we don't know the details of the prey decline. So yes, you can tie them up in a telescopic view, but you cannot do it on more detailed view, which is correct. So that was the only, so far, I must tell you something. The first paper that I wrote, that I participated or led, in 2011, the man-the-fet hunter, I had on the team, and an anatomist from the School of Medicine in Tel Aviv, a guy by the name of Israel Hirschkowitz. And he wrote to me after we finished, and everything was published, he said, I learned a lot, he wrote to me an email. I learned so much from you. It was a nice experience, it was a great experience. And from now onward, nobody will be able to publish a paper about human evolution without citing this paper. Well, let me tell you, nobody cited this paper. So, you know, you wait, you hope the people read it, and you hope that they relate to it, but that's life. I don't know, I don't care. A couple of personal questions, thank you so much. Um, I'm 64, I'm inspired by your later PhD. I'm, I would think of it for myself in the next chapter of my life. And what, what, what age did you get your PhD? And then I'm curious about your own, 67, okay. And, and, and then I'm curious about your own diet if you don't mind my asking. Oh boy. It's always a tough one. I'm aspiring carnivore. That's what I see. Hi, great talk, thank you. What is the rationale for the limits that you place on the possible energy derived from protein? Well, there's, there are studies that, intervenously, I forgot the name of the researcher at the moment, but man, something, I don't remember, but I can give you the later on. He took like 20, I think young guys and injected or intervenously fed them protein and also measured when the production of urea stopped. So, and that was his limit. Now, it's not the best study and it's not, it happened in the 70s, but when you go to hunter gatherers like Eskimos that consume a lot of meat. Again, when, when studies say that it's about 40% that they get the maximum. So you take some structuring protein out of the picture. So you left with about 35%, but yeah, it ties up with that information too. Okay, thank you very much.