Articles, Blog

Crash Course Big History #7: Migrations and Intensifications

November 4, 2019

Hi, I’m John Green. Welcome
to Crash Course Big History. Today we’re gonna be talking
about the spread of human foragers
across the world and the start
of the agrarian era. Mr. Green, Mr. Green, didn’t we
study all that agrarian stuff in World History,
because I’m a very busy person. I don’t want to do it again. Yeah, a couple things,
me from the past. First off, playingZeldaalone
in your basement does not constitute being busy. Also, inCrash Course
World History, we zoomed through
a lot of this stuff because we wanted
to get to, like, the real historyish parts
of history. You know, the parts with
the funny hats and the Mongols. # # But if it weren’t
for agriculture and the surpluses
that came with it, we never would’ve had
funny hats. That’s why we study Big History. So, as mentioned last week, humans anatomically similar
to us have been around for about 200 or 250,000 years. Like, here’s a picture
of one of the oldest known fossil remains of our species
from Ethiopia dated to approximately
195,000 years ago. For the vast, vast majority
of our existence, Homo sapiens
were hunter-gatherers, like… And you’ll remember
that the eruption of Mount Toba about 74,000 years ago reduced
the human population to a few thousand and that scrappy group
of survivors held on, and for the next 60,000 years, human populations migrated
over the world, separating into
their own little Petri dishes. And that was interesting,
because the human experiment could proceed in isolation
in several different zones in the world: the Afro-Eurasia, the Americas,
Australasia and the Pacific. And this was really useful,
because it allowed each of those world zones to develop their own
distinct brand of football, which makes
for such a beautiful game today. Apparently, there was
no football back then. Really?
What did they do all day? Apparently, they were hunting
and gathering. Okay, so by 11,000 years ago,
the human population had recovered
from the Mount Toba disaster and grown to about six
to eight million people. Now, because foraging
requires humans to constantly move on
to new ecosystems to find food while the old ones regrow
and replenish themselves, six to eight million is about the largest population
of foragers that the entire surface
of the Earth could support. Now, you may remember
in the very first episode ofCrash Course World History,
we talked about the mystery of why humans
developed agriculture, even though foraging is easier. One theory involves
so-called Gardens of Eden, where the warming climate
of the Earth created some lush ecosystems
with enough food for foragers to quit migrating and settle down
for several generations. The Natufians, of what later
became the Fertile Crescent in the Middle East,
hunted gazelles and fished and harvested wild grains,
but they weren’t really farmers. But then,
after a few generations of vigorous population growth, food started to grow scarce
in these Gardens of Eden. Given their new relatively
sedentary lifestyle, those humans may have forgotten
how to forage effectively. Also, surrounding areas may have
been already overpopulated with other foragers. So humans had to choose
between starving to death and getting more out of the land
that they were currently on. A choice that historically
we make by trying not to die. These humans already had a deep
knowledge of plants and animals, and if you’ve got organisms
nearby that might be useful to domesticate, like wheat
or goats or wild pigs, bingo, agriculture. Now, of course, there are
also many other theories about why agriculture emerged
around the world, but regardless… Hunter-gatherers
adapted themselves to the resources provided
by the environment, right? But agriculturalist increasingly
adapted the environment to suit their needs. Forcing the environment
to adapt to humans became an increasingly
big deal until, you know, like, today, when it is arguably
the biggest deal of all. Now, all that being said,
the advent of agriculture didn’t, like,
immediately lead to wars and cities and kings
and funny hats. In fact, another 5,000 years
would pass before the first states emerged. So for the first half
of the agrarian era, humans lived in a world
of villages with transient herders
and foragers and the gaps between. Giving up foraging
and settling down did have some down sides
in the form of back-breaking labor
and diseases moving easily among denser
and more numerous populations, but farming allowed humans
to support a much larger number of people within a much
smaller land area than foraging. This was very good for collective learning,
which relies on both the number of potential innovators and the close connectivity
between them. The world population had grown
from roughly six million people at the beginning of agriculture
to 50 million by the emergence of
states 5,000 years ago. Roughly 5,000 times
the size of the population that survived
the Mount Toba disaster 70,000 years prior. And because early farmers
didn’t really understand or have the technology
to solve the problem of pooping
near the drinking water, another upside was that we invented alcohol, which was safer
to drink instead. So next time you see
a person looking fancy with a glass of champagne,
just remember, it’s a tradition that started from there being too much poop
in the water, and ever since has fueled
millions of bad decisions. States did eventually appear, but not all states
emerged at once, anymore than all agriculture
emerged at once. Agriculture first emerged in
the Fertile Crescent and Egypt around 11,000 years ago,
and then in East Asia and Papua New Guinea
around 9,000 years ago. Agriculture emerged
in West Africa and the Americas around 5,000 years ago, though estimates definitely vary
for the Americas. Accordingly, the first states
to arise were in the Middle East,
where agriculture first emerged, followed shortly by the Chinese
and Indus Valley civilizations. Papua New Guinea
may have invented agriculture around the same time,
but they never developed enough agricultural surplus
to support states. So, yeah, in every world zone,
the invention of agriculture was a precursor
for the rise of states. The key to having a state
is agrarian surplus. If you produce enough food,
you can have a class of people
who don’t need to farm. They can then fulfill
other duties in this increasingly numerous
and complex society, whether they be leaders
or judges who settle disputes, bureaucrats who deal with administration
and infrastructure, doctors who heal the sick,
priests who make sacrifices to vengeful gods, or soldiers
who provide security, or at least extract a portion
of the agricultural surplus for the leadership
through some kind of taxation. And with more people
filling new jobs and generating new ideas
about them, this is also good news
for collective learning. Diversification of labor is also the first step of early states
toward hierarchies and classes, aristocrats and popular
and despotic kings and pharaohs and sultans,
shahs and emperors. It also meant the first
divisions into unequal, unfair and undemocratic
hierarchies, dividing man from man,
man from woman, and the high from the low. All of this brings us back to the Hobbes
versus Rousseau debate. Hobbes viewed life
without state control as nasty, brutish and short, while Rousseau viewed humanity
as largely egalitarian before claims to land and wealth
and property corrupted them. Now, certainly the idea
of an age of innocence or a golden age has been popular
with many philosophers and political idealists
throughout history. I mean, if humanity
had once been perfect and was simply corrupted
by societal structures or political systems, then it would take
only a few tweaks or reforms to get us
back to perfection. Unfortunately,
it now seems clear that a lot of humanity’s evils are created
simply by the bad wiring of our evolutionary biology, and the solution to the problem
is somewhat complicated. It’s very difficult for me to imagine a world in which
humans will say… So where you stand on
this Hobbes v. Rousseau question affects your view of the entire
250,000 years of human history and also your view
about much of human morality, character and potential. Another big history take
on agriculture is this: Consider the sun.
We are made up of the leftovers of its formation and the debris
of stars that came before it, but its role in our history
doesn’t stop there. Fusion reactions happen
in the sun’s core. This generates energy,
which is released into space and takes approximately
eight minutes to get to us. Here on Earth,
plants capture that energy and store it via photosynthesis. Agriculture let’s one species,
us, harness more of that energy. We either eat it or we use it
to feed animals that we eat or we use it to feed animals
like horses and oxen that pull carts
and carry burdens, providing 500-750 watts
of power, about ten times more than
what a human being could do. So essentially,
agriculture is the act of harnessing more energy
from the sun, way more than we could
as foragers. All of this leads to
an interesting perspective. Human history had frequently
been viewed as too chaotic or complex to allow us to find
an underlying trend, a bottom line
or overarching theme. And this, to some people,
makes conventional history differ greatly
from the natural sciences. However, given what we know
of energy and complexity, consider the following. That doesn’t mean
that the bottom line is all there is
to human history. You’ve got political history and the history of warfare and gender history,
class history, art history, environmental history,
oral traditions, creation myths
and much, much more. But none of those would matter
if we were all dead. If you don’t eat,
if you don’t drink, you die. Much of the collective learning,
inventions, shifts in the social structure,
has been geared toward coping with the problem of energy flows as the population continued
to expand by leaps and bounds from a tiny 10,000 people
74,000 years ago to over
seven billion people today. So the beautiful thing
about being able to remember and accumulate the ideas
of your ancestors is that some of their ideas
are great for agriculture. Also other things,
but mostly food. Whether it’s new forms
of irrigation invented in ancient Mesopotamia, or the four-crop rotation
that gradually proliferated across Europe in the 17th
and 18th centuries, these innovations increased
the number of potential innovators
who could exist in a social order
without starving. There was also great innovative
leaps in connectivity. For instance, the invention
of writing in ancient states about 5,000 years ago. Like, starting from a
bureaucratic form of accounting, mostly to count livestock, to an art largely enjoyed
by the elite, writing gradually communicated
more abstract and complex ideas, and those ideas became available
to more and more people as more people could read
until eventually writing became so popular that these days,
everyone writes books, even some of your
Crash Course Big Historyhosts. We also like writing
because it made it less likely that things we’d learned
would be forgotten. Like, when people started
to write down what they knew, that knowledge
became set in stone, sometimes literally. And then, with the invention
of printing in China and later Korea, and the printing press
in Europe, more writing could be produced
and circulated more quickly, and often more cheaply,
than books copied out by hand. All of this turned into
a beneficial feedback cycle. More people go on
to produce more ideas, which raises the carrying
capacity of the population, which in turn, produces more
potential innovators. And we can do it all
without anything bad happening to the environment. What’s that? Oh. Oh, my. So throughout
the agrarian period, collective learning continued
to raise the carrying capacity
of the world. Populations grew from
six million 10,000 years ago to 50 million
by the dawn of states to 120 million by 1000 BCE in the midst
of classical civilizations. By the end of the agrarian era and the beginning
of the Industrial Revolution, 954 million people lived
on the Earth. But while collective learning
gradually raised the carrying capacity
in the agrarian era, it did not keep pace
with population growth. And this is a significant
problem with humanity. Just like any other animals
in nature, we breed until we strain the resources
of our environment. So we are prone
toward unsustainable levels of overpopulation. So every two or three centuries, humans would hit
the carrying capacity, and then the population
would recoil, resulting in famine, disease, periods of infighting
and population decline. In every agrarian civilization, from civil wars between Caesar
and Pompey, the English War of the Roses, to the revolt of the Janissaries
in Ottoman Empire, and similar events
all across the world, the cycles of prosperity,
strain, crisis and civil infighting
repeated themselves. And I do worry a little bit
that when we talk about traditional history,
we don’t do it enough in the context
of carrying capacity. We are, after all, organisms, and we behave a lot like
other animals on this planet. We want there to be more of us,
and we want more resources for that more of us to enjoy. So that broad, big history take
on the agrarian era takes us
to the Age of Exploration. Explorers,
including Christopher Columbus, but also many others, united the previously
isolated world zones of Afro-Eurasia, the Americas, Australasia and the Pacific. Eventually, this combination
of world zones into one unified global network, although not that unified, would produce
an even more astounding rise in complexity:
the Modern Revolution. We’ll talk about that next time.


  • Reply Steven February 20, 2015 at 8:13 pm

    Was this published previously or should I consult an doctor over the extreme deja vu I'm having?

  • Reply Rick Kasten February 21, 2015 at 4:51 am

    Yeah, there's no way this video has had only 150 views.

  • Reply SpazzyMcGee1337 February 23, 2015 at 6:15 pm

    @Big History Project What exactly is your relationship with CrashCourse and this series of videos? The videos obviously seem to be produced largely by CrashCourse, but some your channel had some of the series' videos posted before CrashCourse did. Now you are posting more of the series well after CrashCourse posted them.

    Was the series a collaboration between Big History Project and CrashCourse, and you both agreed to post the videos on both channels?

  • Reply Daniel Artman December 8, 2015 at 3:16 pm

    You guys are beyond super awesome. Thank you.

  • Reply Metusalem979 January 15, 2016 at 2:28 pm

    Nitpicking, but South-Saharan Africa should be singled out as a separate petridish. Don't forget about the Zulu!

  • Reply Leotique December 3, 2016 at 10:06 pm

    isn't this just a re-upload of crash course history from 2012 ?

  • Leave a Reply