John J. Shea

How ancestral Africans survived the Pleistocene

This lecture surveys the survival challenges ancestral Africans faced and the survival skills they used to overcome those challenges. It proposes a new hypothesis about how early humans became so widely dispersed in Africa before launching their global diaspora.

FULL TRANSCRIPT 

I have a Richard Leakey story, but I'm going to save it for the end. So no cutting out early. It's like I do with my students here. The short answer to the question how ancestral Africans survived, the Pleistocene is that they went on to do a global diaspora. We lived every place. The only way to take out humans now is to take out the biosphere. There's only two ways for that to happen. We get a meteor impact, like a dinosaur killer or a large scale volcanism. So we are essentially the unstoppable human species, pretty good accomplishment for what was once an endangered African primate. So, of all the Pleistocene hominins, all these creatures whose names you've heard before these last several days, why did only Homo sapiens survive the Pleistocene? Where our footprints on the moon and their fossils in our museums? If you want to answer to that question, why did we survive? Study survival 

It's common sense. We want to know how people overcame difficulties, what works, what doesn't, who lives, who dies, and why. Now people don't think a lot about survival and this talk and works derived from it or an opportunity for me to bring together two themes, two sets of interests that don't overlap completely. Many people know about my archeological research. I've try to make stone tools more useful for testing hypotheses about human evolution, but I've also been interested in wilderness survival and ancestral skills. These two, like I say, they sometimes overlap in terms of making stone tools and things like this, but that's really the least interesting of their applications. So people don't often think about survival. So what I wanted to start off with here is to introduce you to survival priorities. These are the things that matter. The first priority is first aid. If someone's circulation or airways are compromised, you've got minutes, not days, not hours, not time to read first aid manual, you’ve got minutes.

Shelter, hypothermia, but can kill in minutes. This is an hour's problem. In most survival manuals they advise you start setting up your overnight camp, gather the fuel for your fire and find a way to minimize heat loss to conduction sitting on the ground or convection blowing wind when you have two hours left. The way you assess that is you stick out your hand towards the sun. This distance is one hour, distance is two hours. The clock is ticking. Water, this is a three days problem. People can go for three days without water before they start having problems. If you're in a survival emergency, drink the water from the stream, you'll get sick but in most short-term emergencies, which is to say 72-hour search and rescue operations after 72 hour search and rescue operations success fail more often, 72 hours, drink the water. 

If you can boil it for a minute, you're fine. That'll kill pretty much everything that could possibly kill you. Now that dividing line, that's the line between if you expect search and rescue to be looking for you one through three, deal with those things. If nobody knows where you are and you have to self-rescue, then worry about four, five, and six. Food, people can go for three weeks without food. We really overestimate how much we need food and survival manuals that tell you, you forage this plant, pick up this bug, and that kind of thing. Finding small bits of food like that is a way to boost morale.  You don't need food. It gives people something to do while they're waiting for rescue or they're planning the next step. Signaling, it needs to attract attention to potential rescuers even if search and rescue is not looking for you, there are still people around. 

If you're someplace, the odds are other people are nearby. You need to be able to attract their attention. And lastly, if all other things fail, then you've got to move. You've got to find a way to get from where you are to where the other people are. Now I've found in a deep dive into this subject, which has been ongoing for about 16 years now, thinking about how prehistoric humans survived, excuse me, has led me to some new hypotheses. I think testable ones about human evolution, about larger issues. Now, briefly, I want you to consider stone tools. I am, for want of a better word, a stone tools guy. So that's my initial touchpoint but I'm only going to show you one picture of stone tools, I think just one picture. So stone tools, they are the most common things archeologists find at Pleistocene sites. The museums are full of them. The National Museums of Kenya is probably sinking under the weight of all the stone tools in its collections. Now, stone tools are indisputably useful for cutting things and pulverizing things. What about signaling? Wilderness survival experts and search and rescue professionals recommend making noise to attract their attention to signal other people and repel carnivores. Every park manual, when you go to the national parks, they say, if you run across a bear, don't, “Hey, bear”. Make yourself big, make lots of noise, bang things together, make sharp noises. I want to give you a demonstration. 

This is not how you get rid of bears. If you get rid of bears, you throw the rock at them. Black bears are cowards, grizzly bears, pray. Okay, listen, that's what you do. Prime numbers 1, 3, 5, and 7. Nature hates prime numbers that's why she made so few of them. All right, marking trails. Banging rocks together creates fracture. Fracture creates stone tools, and per the instructions of the custodial staff, I will not be flint napping in doors today. 

This little rock, I can tell this is made from a rock on the island. Somebody took local rocks and made this. These stone tools are all over the campus because I've been here for 30 years. This is shale from upstate in New York, a thing called the Norman Skill Shale. So just by looking at these two rocks, I can tell something the fracture patterns in this. This was made by one of my students. This is one of mine probably from about 10 years ago. These are not mute stones. They speak if you know how to listen. Now, people haven't, it's a funny thing about making stone tools. I've been making them for a very long time, and I've had this experience and pretty much everybody else who's made stone tools at some point or another has had this experience. Someone has gone to them and said, it's too noisy and you're making a mess. That's the point. Being noisy and making a mess is a great way to survive in the great outdoors. Now, it's interesting, in more than two centuries of archeologists writing about what motivated early hominins to make stone tools, marking trails, inhabitation sites, and signaling by making noise appear nowhere. 

Wow. Alright. The script says why, but wow. Now why is this the case? Well, few archeologists make a new stone tools fine, but it's relevant. There's nothing about making stone tools that makes you an expert on evolution. There's nothing about making stone tools that necessarily makes you an expert on survival. Becoming an expert on survival requires you to study survival but stone tools, excuse me, maybe it's that survival experts don't study archeology. That's false. When I began my deep dive into this wilderness survival community, I was amazed how many people had studied archeology. Now, granted, when I'd asked them, they'd say, well, mainly I'm interested in the last few centuries or last thousand years or Native American cultures before the Europeans arrived. This sort of thing. It's not that survival experts don't care about stone tools, or excuse me, don't care about archeology. I think the answer is that few Pleistocene archeologists study survival, and I think that's true and it is highly relevant. I wonder if anybody ever told Louis Leakey he was making too much noise and he should move his flint napping show elsewhere. 

I've recently published and proposed a new approach to this problem. I call it “Survival Archeology”. The manifesto, if you will, came out a few weeks ago, so if this is unfamiliar to you, it's simply it's newly published. Survival archeology uses insights from bushcraft, which is to say, modern day survival skills and ethnography to develop hypothesis about how prehistoric hominins, Pleistocene hominins overcame difficulties. It tests those hypotheses using archeological evidence, and because I wanted to make it useful to more than just archeologists and paleoanthropologists, survival archeology informs strategies for coping with present day and future difficulties. So in a word, well, four of them, survivor archeology is applied anthropology. Humans have an impressive array of ancestral survival skills. Skills we've inherited from our Pleistocene ancestors, and when we use them, we integrate them. We put them in combinations that are more than some of their parts. Now I'm going to go over each of them, there's a bit of jargon. Some of them are more clear than others. Predictive hallucination. How many of you checked the weather this morning? That's predictive hallucination. You are able to take an incomplete set of information and then make accurate predictions about what you should do in the future.

How many of you have shoes that have laces? Well, you tied those shoe laces you engaged in powerful precision grasping, this sort of grasping (proceeds to illustrate). Endurance, bipedalism, walking and running, many of our major health problems today in industrial societies. Other result, not of too much endurance bipedalism, but too little endurance bipedalism being able to walk for miles and miles and run at a consistent pace with high energetic efficiency. These are ancestral skills. Spoken language; I could give this lecture without using syntax or grammar, but I don't think you'd enjoy it very much. So spoken language is important. It adds information to vocalizations and prosociality, prosociality simply put means working together to help somebody else. 

You're driving down the road, you see somebody has a flat tire, you pull over the car, you assist them, you're pro-social. You're a boy scout, former boy scout or girl scout, you do your good day for the day, that's being pro-social. Now, these are evolved qualities, but they can all be improved with practice. I didn't speak as well as well as I do now when I was seven. I was going to say, there're skills you can improve with practice. This is an analog set of skills, not a digital set of skills. Our nearest living primate relatives, they don't integrate their survival skills, at least not as well as we humans do. They don't debate solutions to difficulties. A chimpanzee symposium like this wouldn't last very long, it would be pretty ugly frankly. They don't gather transport, excuse me, they don't transport, gather, store and share food. 

If you've seen countless films of what happens when primatologists with good intentions provisioned chimpanzees with bananas or oranges of these sorts of things. There's a reason why Jane Goodall kept her son in a cage. It wasn't keeping him away from the food. They don't treat or carry injured adults. There is no Red Cross chimpanzees, and this has an important implication. There's no such thing as Simeon Search and Rescue. What that means is that an ape that is unable to move on its own and remains alone as a dead ape. Contrast that with the enormous efforts we make to rescue lost and injured hikers, hundreds of people get involved volunteering their own time, volunteering their energy to rescue individuals. 

So why us? Why am I not? Isn't the Neanderthal faction in the audience throwing rocks at me in this sort of thing? Well, evidence for these ancestral survival skills precedes first appearance dates of our species, Homo sapiens and the fossil record. That first appearance dates vary depending on the criteria, criteria one uses, but the range of dates currently in play ranges between 200 to 300,000 years ago. Now, if we cast back beyond 200, 3000 years ago, one can make strong cases for each of those ancestral skills being in practice, maybe not, certainly not the same way throughout the hominin range, but the skills are there. Now that has a really important implication. It means other hominins had those skills too. So the important question isn't did they have these skills? The important question is in anything about evolution, it's about differences. What did ancestral Africans do differently than other hominids? 

We have to start in the present day. This is basic science, basic uniformitarianism. We have to base our hypothesis about the past, at least our initial hypothesis on things we can observe today. One of the important differences between us and our nearest primate relatives who are also social, who also use tools and who also live in Africa, is that we integrate our skills better than they do. I proposed in the book, in other works, I call the Integrative Ancestral Survival Skills hypothesis, and my editor at Cambridge University Press insisted I add integrative and not use an acronym. So if ancestral skills, if Ancestral Africans integrated their survival skills better than other hominins than individual Ancestral Africans, that is to say the Africans who became ancestral could have increased their reproductive success, their individual reproductive success by dispersing as far away as possible from any others among them, who also had the ability to integrate those skills as effectively. They wouldn't want to literally put all your eggs in one basket. They would also have incentives to infiltrate other hominid populations who did not integrate those skills as well. 

Thirdly, they would have strong incentives to leverage survival difficulties to their own advantages. So, oh no, the fire went out, wait, I can fix that. You're the big man on campus. This is what I call the Dark Gilligan hypothesis. Gilligan's Island marooned and Gilligan always creates trouble. It stands to reason individual Ancestral Africans might've had incentives to provoke survival emergencies so that they could leverage those emergencies to their own reproductive advantages. Remember, they were Africans, there are ancestors, neither of those two things means they're nice people. They're just reproductively successful and in the long run, that's what evolution cares about. So we've gone around and Curtis mentioned a debate about modern humans. It's a term I find difficult, but we can disagree respectfully and professionally about it. I've called them Ancestral Africans because I need a name for them. But I think Rob made a good point in one of his slides the other day that what we call Africa is geopolitical Africa, and then the Pleistocene times what the environments that we think a characteristic of Africa extend into south and southwestern Asia. So I think a more accurate term, rather than referencing a modern geographic term that these Ancestral Africans would not understand would be to call them the bow, excuse me, the boats, bows and beads people. I think three key lines of archeological evidence support the hypothesis that integrative ancestral survival skills made the difference in our species fortune. So more specifically, watercraft, complex mechanically projected weapons, which is to say weapons that don't require simple physical force, but an additional launcher and missile component and symbolic social media, boats, bows, and beads. 

If we survey the archeological record as it stands before us now evidence for boats, bows and beads falls closely on first appearance dates for Homo sapiens and last appearance dates for other hominins in Africa and elsewhere. We don't often think about bows boats and beads as ace to survive and dispersal. So I want to lay this out for you a little bit more. Clearly. I'm ripping through time there aren't I. Boats enable safe water crossings and friction free long distance movements which occurred. Remember we were in Tanzania doing survey. We go to these villages and every single time we'd say, “What's up there? “Crocodiles” Or “What happened here?” “Somebody got eaten by a crocodile”. Every single village. So boats enable safe water crossings and remove water as a barrier, and they turn water, flowing water into a highway Africans crisscross rivers, as is parts of Southern Asia too. 

Bows are versatile, lightweight weapons that one can use against large animals or small animals and shoot in 360 different directions. You can shoot down, you can shoot up, laterally. This way you can even shoot blind if you really feel like a challenge. And beads, beads are verifiable assertions of survival skills. Making these small holes in these nefarious or tick shells requires very precise precision grasping and use of small tools. I like to think of these maybe as I was in Boy Scouts. I like to think of these beads, not so much as I'm part of this group, I'm part of that group. I like to think of these beads as possible merit badges. 

They offer a verifiable hypothesis about skills and offer incentives for others to accept individuals into their groups. Okay, so maybe that's again the Old Boy Scout's perspective. Now, when archeologists interrogate the past, we do so in two distinct kinds of ways. They're extremes rather than dichotomies. We ask “who” questions about prehistoric hominin identities, and we ask “how” questions. We spend a lot of time and energy on “who” questions. I think archeologists need to spend more time and energy on the “how” questions on how they overcome survival difficulties type questions. So, I'll put it to you, this is a hypothesis, not a conclusion. Do skill integration, dispersal infiltration and leveraging explain why Ancestral Africans survived and other hominins did not. Testing this hypothesis requires research on a wide range of Pleistocene time periods. So where to start? Well, I think you can read the answer. Richard Leakey inspired and aided decades of research in the Turkana Basin. 

It's easier now than ever, ever before to find evidence about how Pleistocene hominins overcame survival difficulties. But evidence for overcoming survival difficulties in more recent periods is important too. We don't live in a Pleistocene Ice Age any longer. Like I need to tell you the guys this after yesterday. We live in a rapidly heating Anthropocene world and the Jade Green Sea here, is a place that can provide important lessons for the future. Now I said before applied survival archeology is applied anthropology or it's nothing at all. If it doesn't have a practical application, it's not worth spending time doing it. The Turkana basins’, people have struggled with extreme heat and aridity for thousands of years. Now, their current difficulties are preview of what other people living elsewhere facing the future. Right now, this is Lake Turkana. In 600 years, this could be France. Helping them to help themselves is the right thing to do. It's payback for putting up with the skull hunts and the square holes we dig in their backyards. Helping your neighbors overcome difficulties is a uniquely human survival strategy. Thank you. 

Do you want to hear Richard leaky story? Two minutes. Alright, she says, let me tell the story. Richard was many things, but he was also Stonybrook professor, which means part of his job is to educate the students. At some point, some years early years in as TBI was getting going, someone engaged Richard to give a lecture in front of all the students and instructions went out, “Make sure students attend this”. So I gave students extra credit from my human evolution and archeology class to attend Richard's lecture. Richard's first words, “It's alright to break the rules, don't just get caught”. So to verify the students that attended, I said to them, you must write down something you learned from Richard Leakey's lecture. One answer, “It's okay to break the rules, just don't get caught”. The next answer, “It's okay to break the rules, but if you get caught lawyer up”, and I love this one. This is one by a student who I'm pretty sure is now a college professor. There are no rules!

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