If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Video transcript

DAVID CHRISTIAN: Now, let's look at the first of the three great ages of human history. We call it the Paleolithic era. In Greek, paleo means "old", lithic means "of stone", so this is the era of stone tools. For archeologists, the Paleolithic era goes back at least two million years because it covers the whole period during which humans or our ancestors made stone tools, so it goes back to the time of Homo habilis. But we're focusing on Homo sapiens, so for us the Paleolithic era begins when Homo sapiens first appeared somewhere between 200,000 and 60,000 years ago. And it ends with the appearance of agriculture about 10,000 years ago. So how can we study our ancestors who lived in the Paleolithic era? Well, we use two main types of evidence-- archaeology and anthropology. The archeological evidence consists of the remains that they left behind. Now, this includes both the bones, the remains of their bodies, and the remains of the things they used-- their stone tools, their ornaments, and their artwork. Anthropology uses studies of modern societies that were probably quite similar to the societies of our ancestors. These are small scale societies that foraged for their food and other resources. So, using these evidence, can we figure out how they lived? If you had lived in the Paleolithic era what would your life have been like? How much of your social and family life revolves around eating? Probably a lot. Who you eat with, what you eat, and where you eat can tell us a lot about you. And this was also true of our Paleolithic ancestors. But, of course, they didn't have restaurants and groceries, instead they relied on a technique that we called foraging. So what's foraging? Well, in a sense all animals forage for the food and other things they need. That is to say they look around the environment and they pick up those things when they find them. So birds, for example-- they gather up worms, they gather insects, and they pick up twigs for their nests. But human foraging is very different, and what makes it so different is the vast range of different techniques different communities use. So why is there such a variety? Well, this brings us back to collective learning. Each community develops intimate knowledge of its own variety and a whole series of specialist techniques for dealing with the particular plants, the particular animals that they have in their environment, so each community develops its own technologies over time. And this explains why human societies have managed to settle such a vast range of different environments all around the world. Archaeology can give us lots of clues about how our ancestors lived. Let's return to Blombos Cave on the Indian Ocean coast of South Africa. It was inhabited by humans between about 95,000 and 55,000 years ago. And it contains lots of evidence about how our ancestors lived. First, we find the remains of some deep sea fish. Now, that's pretty impressive. It suggests that they were good fishermen and it may even mean that they had pretty good boats. We also find the remains of shellfish, so they were exploiting resources on the beaches and also small reptiles which they were catching. And we find the ash from fires, which they were probably using for cooking or heating, so they controlled fire pretty well. We also find very beautiful little stone tools and very interestingly some of these were hafted-- that is to say they used glues or fibers to attach them to sticks to make them more useful. And finally-- and particularly interesting for an archaeologist-- we find stones... clay-like stones that are known as ochre on which we find little marks. Now, these maybe early signs of art or they might even be early signs of writing. Now, the other major form of evidence is anthropology. And what anthropologists do is study modern societies as we've seen that behaved a bit like them. In the Americas, in South Africa, in Australia, in parts of Siberia there are still some societies today that depend at least partly on foraging. Now, of course they're modern societies in all sorts of ways. Nevertheless we can learn a lot about them. About what foraging means by studying those societies. In particular, we've learned that if you cannot survive from foraging you probably need to forage over a pretty large area, so that even a large area can only support a very small population. You'll also probably gonna have to be nomadic. You're gonna have to tour around that area to get different resources at different times of the year, so this means you're gonna get very familiar with it. And you're probably gonna travel to familiar camp sites each year. Now, if you're nomadic, you're gonna have to travel light, so foragers don't seem to accumulate much in the way of property. This may also help explain the fact that foragers seem to very often limit population growth. Now, foragers seem to travel around in communities-- small communities of perhaps ten to 50 people at any one time that are probably related to each other. But those communities were not isolated. We also know that they tended to link up with their neighbors. Very often what they do is they meet with their neighbors at a time and place where there were lots of resources to support a lot of people for maybe two or three weeks. In Australia, for example, in the snowy mountains, there's an area where the so called Bogong moths flourish for two or three weeks, so millions of Bogong moths provide a feast for these sort of parties. Now, what do they do when they meet? Well, they share stories, they share ideas, they share dances, they may play games, but they also share people. So people move from group to group to marry or to get away from their enemies, so in this way, people circulate amongst these groups. So foraging groups exist in networks within which collective learning can take place but, of course, those networks are pretty small by modern standards. Because we're used to modern lifestyles, if you and I were transported to a Paleolithic community we'd probably find life pretty tough. But studies of modern forages suggest if you were used to that lifeway it could be pretty good. In some environments there was a wide diversity of foodstuffs and different resources, traveling around meant that life was varied. It probably kept you healthy. How did they see the world? Well, let's be honest: we don't really know. But studies of modern foragers give us a pretty good guess. Most modern foragers seem to think of the universe, the entire world, as full of spirits of different kinds-- spirits in the trees, in the rocks, in the rivers, in the stars, in the mountains. Some of them benign, some of them friendly, some of them really mean. It's as if they thought of the whole universe as full of life, as full of conscious life, and that's perhaps not such a bad way of thinking about the universe. But without records, it's probable that they didn't have a sort of modern sense of deep time or big history. Although we know that some big events, such as volcanic eruptions or perhaps asteroid impacts could linger in their memories sometimes for centuries or even thousands of years. As humans collectively learned more and more about their environments, they began to migrate into new environments. Now, at the sign... at the time these migrations would have seemed completely insignificant. No one would have really noticed them. But in retrospect, what we can see is that these tiny migrations were what led our ancestors to migrate around the entire world, developing new technologies as they did so. We know that some humans left Africa about a hundred thousand years ago, but real significant migrations began after about 60,000 years ago. We also know that just before those major migrations, human numbers dropped very drastically to perhaps just a few thousand. We know this because of genetic evidence. And it's probable that the cause was a series of massive volcanic eruptions. That's a reminder that there was no guarantee that our species would survive to the present day. Then, as if in a rebound, humans began to migrate faster and faster. By 50,000 years ago, we know there were humans in Australia. To get there, they must have had pretty sophisticated navigational skills because they had to cross quite a large body of water. They also needed the ability to use the entirely new suite of animals and plants to survive from. From 25,000 years ago, we know there are humans living in the icy conditions of Ice Age Siberia. To live there, they had to be able to hunt mammoth. Think about it. That was pretty tough. They used mammoth bones to build houses to keep warm. They also used bone needles to tailor very, very nicely made skin clothes to keep themselves warm. From about 15,000 years ago, we have evidence that humans went to the Americas. So all in all, by about 10,000 years ago, we know that humans have settled all parts of the world, apart from Antarctica, so there's nowhere else, really, or there's not much room to settle now. Coincidentally, at about the same time, global climates began to change as the Ice Age has ended. Now, these two changes-- the settlement of the entire world and changes in global climates-- would set human history off on an entirely new trajectory. Why?