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Current time:0:00Total duration:11:27

Video transcript

this timeline here covers 200 thousand years from 200 thousand years into the past to the present and just to get a sense of the scale of this if we were to go 2,000 years ago to the time of the Roman Empire that would be roughly here on the timeline if I were to say when were the pyramids built that would be roughly there on the timeline so by human standards this is a very long period of time and I didn't choose this timespan arbitrarily 200 thousand years is about how long we believe anatomically modern humans have been on our planet our subspecies of Homo sapiens sapiens now the reason why I show these stone tools is because the ages the period of modern humanity or even pre-modern humanity are named after the types of tools that have been found in archaeological digs so most of even pre human or near pre human and human history has been the has been the Paleolithic period or Old State stole Stone Age paleo paleo for old lithic come from coming from lithos for stone so Paleolithic the Old Stone Age is the great bulk of human history and there's also a methyl Lucic thick that comes about 15 20 thousand years ago but then around ten thousand years ago the stones have a much more polished appearance to them things like this and so that period from about ten thousand years starting with about ten fifteen thousand years ago depending what part of the world you look at is referred to as the Neolithic period Neolithic referring to new stone and on top of this timeline I have also shown what's happening at a very large scale climactically on the earth so these blue periods are ice ages and these reddish orange periods are the periods in between ice ages and so you can see the last ice age ended roughly 15,000 years ago and it began roughly 100 and 10,000 years ago now I'm giving you all this context about these Paleolithic Neolithic and the ice ages because we're going to talk about probably the most important series of events or innovation in all of human history and that is agriculture agriculture for most of human history over this period Paleolithic period over most of the timeline going up about until about ten or fifteen thousand years ago our ancestors were hunter-gatherers they would have to chase the game wherever it might be they couldn't settle down in one place maybe there are a few that we're near some sources of fish where they might be able to do some basic fishing but they would have done hunting like this it would have been gathering which means getting berries or mushrooms where they could find it it probably was eating a lot of things like insects and that is most of human history but then around ten or fifteen thousand years ago we have the advent of human beings taking nature into their own hands instead of saying let's just follow the game wherever the game might migrate to let's actually domesticate these animals let's take some of them start breeding them so they're more suitable for human consumption so that they are easier to raise maybe more robust and we will we will breed them and we will raise them for milk for meat we also started to domesticate plants instead of saying okay let's just grab those berries there where it happens to emerge let's actually start to plant things and on a very predictable way be able to harvest them and so have a more predictable food supply both of these things allowed human beings to have a higher population density to start to to settle down to have a more sedentary life and this is a huge huge huge deal just to get a sense we believe that the carrying capacity for the planet for human beings as hunter-gatherers is ten million people and that is what we estimate the world population was at around the time of the last ice age or shortly afterwards and that's because a tribe of 100 hunter-gatherers is going to need 50 square kilometers to a hundred square kilometers to hunt and gather from or actually 500 where some of the estimates I've seen and it might seem like a lot of area that you would need to hunt and gather from but imagine if you and your family had to go live in the woods now how much food could you actually find you would have to walk miles and miles per day if you're trying to hunt you would have to walk miles and miles per day to get whatever wild grains or berries or whatever or mushrooms or whatever out or insects that you might consume but then with the advent of Agriculture it allowed for much much higher density population in fact going from the birth of this of Agriculture which happens in the Neolithic period the the dawn of Agriculture coincides with the Neolithic period they're often used somewhat interchangeably going from that period ten fifteen thousand years ago to the time of ancient Rome's we're talking acculturated from ten million to roughly two hundred and fifty million and that's 25 X and we know that from the time of Rome till now another two thousand years with agriculture our population has gone up 28 X it's growing exponentially to seven billion and there's no way that we could have had this level of density without agriculture now a key question is is why did a grrah emerge right then well one theory is is well it seems to be only and I put only I'll say only in quotes only a few thousand years after the end of the Ice Age maybe that you had positive climate change at least from a human point of view that allowed land to be to support agriculture that seems like a reasonable theory although you might say well we've had other periods where we didn't have an ice age how can we see no evidence of agriculture then and one counter argument or explanation I've heard for that is anatomically modern humans started to emerge around 200,000 years ago but that doesn't mean that they're the way they thought or that their brains were the same as modern humans and so maybe in this period the human brain that just wasn't capable of performing or thinking of agriculture other theories are is that the human population through hunter-gathering kept increasing over time and it was right after the last ice age that you really got close to this this critical mass of population at which point it for every extra human to be born well another human would would not be able to live or not be able born because there was a fixed supply of food as hunter-gatherers and so you could say out of necessity maybe a tribe here or a little group there started to say hey well what if we started to if we start to domesticate some of this cattle or if we started to plant crops all of a sudden they would start to have a higher density in their population could increase and not only would they be able to survive but they could also be very dominant in things like conflict once you start having agriculture and as agriculture advances as I mentioned these people could be more sedentary they wouldn't have to move around they wouldn't have to move around all of the time that allows them to create even defensive structures you you could have specialization where not everyone is having to worry about specialization not everyone is having to worry about food all of the time and so you could develop warriors you could have technology developing especially weapons and so not only would that tribe or that group be able to get higher density but they would be able to defend their property in fact they would probably care a lot more about property because they use it to farm versus hunter-gatherers might just view that as their territory that they wander over in order to find food now whatever the actual cause of the birth of Agriculture and has had profound implications on our society you would not have had the birth of city states without agriculture city states had high density populations they needed they could not have been supported hunter-gathering you could not have had the development of technology which me people needed more time you needed specialization in order to have that it's I would say fair to say we wouldn't even have our modern our modern civilization would not have been possible without agriculture I would not be making this video to you right now in fact most of us wouldn't have even been up around on the planet because the planet when the Mayville support are really immensely large population without not only agriculture but an ever advancing a technological or technologically advancing agriculture so it might seem like a small thing you go from hunter-gatherer to agriculture but it's been one of the most maybe the most profound I love probably up there with language and writing the things that have defined what makes humans humans and to get a sense of where this agriculture was born here's the various regions that we believe agriculture emerged from the Levant right over here in the eastern Mediterranean modern-day Middle East Syria Israel Palestine Iraq sub southeastern Turkey this is one of the areas where we think agriculture first emerged on the order of ten to fifteen thousand years ago we believe rice came from China I've seen estimates anywhere from six to thirteen thousand years ago you have the potato and other crops coming from the Andes thousands of years ago and this is just a sample of the areas where we see agriculture both domestication of crops and animals first emerging and what's interesting is over time we're likely to discover other places as we have more archaeological digs and we find more fossil evidence of ancient ancient agriculture and ancient peoples and even the timeframe where we believe this happened the 10,000 12,000 15,000 years ago that's likely to maybe move back a little bit as we discover older and older evidence so I'll leave you there but the big takeaway is most of human history we were not only making rough stones for our weapons and our tools but we were chasing animals wherever we could find it we didn't have predictable food sources we were we were gathering fruits and and and grains and insects wherever we could to support our families and there was a limit on how many humans could be around but shortly after the end of the Ice Age it all changed you had a population explosion and we think that is due to agriculture