When We Tamed Fire

Summary

In this episode of Eons, Hank discusses the origins of fire use by early human ancestors. Archaeologists discovered evidence of ancient fires at sites like Koobi Fora, Kenya, suggesting that hominins like Homo erectus may have used fire over a million years ago. The video explores how fire not only allowed early humans to cook food, improving calorie intake and aiding in digestion, but also helped them survive in colder climates. While much remains unknown, the mastery of fire was pivotal in shaping human evolution, body size, brain development, and migration.

Takeaways

• 🔥 Archaeologists at Koobi Fora in Kenya discovered reddish-orange sediment patches resembling those left by modern campfires, suggesting ancient fire use.
• 🗺️ The site also yielded a hominin jawbone and stone tools dating back 1.6 million years, hinting at the possibility of early fire use by our ancestors.
• 🤔 Researchers ponder whether these hominins could have created fire or merely utilized naturally occurring fires, like those from lightning strikes.
• 🔍 The transition from utilizing natural fires to controlled fire-making is a significant evolutionary step, potentially linked to our ancestors' expansion into new environments.
• 🌐 The ability to create fire on demand marked a pivotal moment in human history, altering our interaction with the environment.
• 🧬 The use of fire has been challenging to study due to its transient nature, leaving little archaeological evidence behind.
• 🍲 Cooking food with fire was a game-changer, making food easier to digest and providing more energy, which was crucial for survival.
• 🌡️ Fire's warmth likely facilitated human migration to various climates, expanding our species' ecological range.
• 🦴 Homo erectus is a prime candidate for the species that may have first cooked food, given its physical adaptations and widespread migration.
• 🔍 Evidence of regular cooking only appears much later in our history, around 350,000 to 400,000 years ago in the Levant, challenging the timeline of Homo erectus's fire use.
• 🌍 The spread of fire use outside Africa is marked by later evidence in Europe, suggesting that early human migration might have occurred without the aid of fire.

Q & A

What significant discovery did archaeologists make at Koobi Fora in the early 1980s?

Archaeologists discovered distinctive reddish-orange sediment patches that resembled the patches of baked earth left by modern campfires, suggesting the possible use of ancient fire by our distant ancestors.

What evidence at Koobi Fora led researchers to consider the possibility of ancient fire use?

The presence of jawbone of a fossil hominin and evidence of stone tools dating back about 1.6 million years ago, along with the reddish-orange sediment patches, led researchers to consider the possibility of ancient fire use.

How did the use of fire potentially influence human evolution?

The use of fire could have sparked evolutionary change by allowing our ancestors to expand into new environments, cook food, and keep warm, which in turn influenced our body size, musculature, and brain development.

What is the earliest possible evidence of repeated, regular cooking in the archaeological record?

The earliest possible evidence of repeated, regular cooking dates back to about 350,000 to 400,000 years ago in the Levant, specifically at the Qesem cave site.

What are the challenges in studying the use of fire in human history?

The use of fire is difficult to study because it is ephemeral and leaves little evidence behind, such as ashes that can be easily blown away or washed away by water.

How did the ability to cook food with fire impact our ancestors' nutrition?

Cooking food with fire made it easier to chew and digest, broke down toxins in plants, killed pathogens, and made food more energetically efficient, providing more calories and thus improving nutrition.

Which hominin species is considered a likely candidate for the first to master the use of fire?

Homo erectus is considered a likely candidate for the first hominin species to master the use of fire, based on its physical adaptations and the timeline of its migration out of Africa.

What is the significance of the discovery of burned bones and plants at Wonderwerk Cave in South Africa?

The discovery of burned bones and plants at Wonderwerk Cave suggests that Homo erectus may have been the hominin that built those fires, as the tools found there are associated with this species.

What is the term 'phantom hearths' used to describe in the context of the Gesher Benot Ya’aqov site?

The term 'phantom hearths' refers to areas at the Gesher Benot Ya’aqov site where fire might have been used, as indicated by burned seeds, wood, and flint, but without a clear campfire ring of stones.

How does the lack of evidence for fire use at Dmanisi in the Republic of Georgia pose a paradox in understanding human evolution?

The lack of evidence for fire use at Dmanisi, despite Homo erectus having migrated there and the cold climate, poses a paradox because it suggests that this species may have evolved large brains and bodies without the additional energy gained from cooking food.

Outlines

00:00

🔥 The Discovery of Ancient Fire Use

Hank introduces new merchandise featuring an Eons pocket tee shirt and invites viewers to purchase it from DFTBA.com. He then transitions into a discussion about the early use of fire by our ancestors. Archaeological findings at Koobi Fora in Kenya, including reddish-orange sediment patches resembling those left by modern campfires, suggest that hominins may have used fire as early as 1.6 million years ago. The narrative ponders whether these ancient beings created fire or merely utilized naturally occurring fires. It highlights the significance of fire in human evolution, such as the potential for cooking food, which would have been a transformative development.

05:04

🌿 The Impact of Fire on Human Evolution

This section delves into the profound effects of fire on human evolution. Cooking food with fire is emphasized as a critical advancement, as it made food easier to digest and more nutritious, thus conserving energy for the body. The use of fire for warmth is also highlighted as a factor that may have facilitated human migration to various climates. The focus then shifts to Homo erectus, a species with traits suggesting a diet that included cooked food and the ability to adapt to diverse environments. However, the timing of Homo erectus's existence relative to the earliest evidence of fire use raises questions about the exact role of fire in the development and migration of this species.

10:07

🌍 Fire's Role in Early Human Migration

The narrative continues with the exploration of fire's role in the migration of early humans. It discusses the challenges in connecting the dots between the evolution of Homo erectus and the use of fire, given the discrepancies in the archaeological timeline. Evidence from sites like Koobi Fora, Wonderwerk Cave, and Gesher Benot Ya’aqov is examined, suggesting the presence of fire use and cooking. The discussion also touches on the presence of fire use outside Africa, particularly in colder climates, and the potential candidates for the species that may have harnessed fire, such as Homo heidelbergensis. The paragraph concludes with the acknowledgment of the many paradoxes and questions that remain in understanding the origins and spread of fire use in human history.

Keywords

💡Homo erectus

Homo erectus is an extinct species of hominin that lived from about 1.9 million to 143,000 years ago. It is known for being the first of our genus to migrate out of Africa and is often considered a candidate for the species that first harnessed fire. In the video, Homo erectus is discussed as potentially being the first to use fire, which would have had significant implications for its ability to expand into new environments and evolve a larger body and brain.

💡Fire use

Fire use refers to the ability of early humans to control and utilize fire for various purposes such as cooking, warmth, and protection. The video explores the significance of fire use in human evolution, suggesting it may have been a catalyst for physiological and behavioral changes. The script mentions archaeological evidence of fire use at sites like Koobi Fora and Wonderwerk Cave, indicating its importance in the development of our ancestors.

💡Archaeological record

The archaeological record consists of the physical remains of past human life and activities, which provide evidence of human behavior and culture. The video discusses how the archaeological record is used to study the use of fire by early humans, with examples such as the discovery of burned bones and heated rocks at sites like Koobi Fora, which suggest intentional use of fire.

💡Evolutionary change

Evolutionary change refers to the process by which species change over time through genetic variation and natural selection. The video posits that the use of fire may have sparked significant evolutionary changes in our ancestors, such as the development of larger brains and bodies, which are adaptations that allowed for more complex behaviors and survival in varied environments.

💡Cooking

Cooking is the process of preparing food using heat, which can transform the food's texture and chemical composition, making it more digestible and nutritious. The video emphasizes the importance of cooking in human evolution, as it allowed our ancestors to extract more energy from their food, which would have been crucial for supporting a larger brain and body size.

💡Calories

Calories are a measure of energy, and in the context of biology, they refer to the energy content of food. The video discusses how cooking food increases its caloric efficiency, providing more energy to our ancestors, which would have been essential for the increased energy demands of a larger body and brain.

💡Phantom hearths

Phantom hearths are areas where evidence suggests fires were made, but without the clear remains of a hearth structure. The term is used in the video to describe findings at Gesher Benot Ya’aqov, indicating that hominins were familiar with fire and could create it at will, which is an important step in the control and use of fire.

💡Homo heidelbergensis

Homo heidelbergensis is an extinct species of hominin that lived from about 600,000 to 200,000 years ago and is considered a possible ancestor of both modern humans and Neanderthals. The video mentions Homo heidelbergensis as a candidate for the species that may have used fire at sites like Beeches Pit and Schöningen, highlighting its potential role in the spread of fire use.

💡Paranthropus boisei

Paranthropus boisei is an extinct hominin species known for its robust skull and large teeth, adapted for a diet that likely included hard plant materials. In the video, the script notes the presence of Paranthropus boisei fossils at Koobi Fora, where evidence of fire use was also found, suggesting that while Homo erectus is often associated with fire use, other species may have been present and possibly influenced by it.

💡Eons

Eons is the name of the show being discussed in the script, which explores various topics related to deep time and the history of life on Earth. The video script is for an episode of Eons that specifically discusses the use of fire in human evolution, indicating the show's focus on significant events and developments in our past.

💡Dmanisi

Dmanisi is an archaeological site in the Republic of Georgia that has yielded fossils of early Homo erectus dating back 1.8 million years. The video mentions Dmanisi as an example of a site where Homo erectus is known to have lived outside of Africa, but without evidence of fire use, raising questions about how this species adapted to colder climates.

Highlights

Introduction of new merchandise featuring an Eons pocket tee shirt.

Discussion on the early 1980s discovery of reddish-orange sediment patches at Koobi Fora, Kenya, resembling ancient campfires.

Hypothesis that the red patches might be signs of ancient fire use by distant human ancestors over 1.6 million years ago.

Question on whether early hominins could create fire or merely utilized naturally occurring fire.

The evolutionary significance of fire use, potentially leading to an expansion into new environments.

The difficulty in pinpointing the exact time and species that first harnessed fire due to its ephemeral nature.

The impact of fire on human evolution, particularly in cooking food and its benefits.

Cooking food with fire as a precursor to the digestion process, making it more energy-efficient.

The role of fire in expanding the geographical range of early humans by providing warmth and light.

Proposal that Homo erectus, with its physical adaptations, might have been an early candidate for cooking food.

The discrepancy between the timeline of Homo erectus and the earliest evidence of regular cooking.

Recent findings at Koobi Fora suggesting more definitive evidence of intentional fire use.

Evidence from Wonderwerk Cave in South Africa pointing to the use of fire by Homo erectus.

Discovery of 'phantom hearths' at Gesher Benot Ya’aqov in Israel, indicating familiarity with fire among hominins.

The appearance of regular cooking behavior in the Levant around 350,000 to 400,000 years ago.

The lack of fire evidence at Dmanisi in Georgia, despite Homo erectus presence, raising questions about early human adaptation to cold climates.

The late appearance of solid evidence for fire use in colder climates of Europe around 400,000 years ago.

The ongoing paradoxes in understanding the origins and spread of fire use in human evolutionary history.

The legacy of fire taming in our current human bodies, reflecting its influence on our size, musculature, and brain capacity.

Transcripts

Hi everybody, It's Hank. We’ve got new merch. I’m wearing it right now. It's this new

tee shirt! It's got an Eons pocket on it. It’s comfy, it's nice thick fabric, it's

got a good design, it has a functional pocket! And now I have one of my very own.

If you want one too, you can get one at DFTBA.com. There's a link in the description!

And we would appreciate it so you can show everybody all over the place

how much you love this show

Now, it's time to talk about fire.

In the early 1980s, archaeologists working at a site in Kenya called Koobi Fora noticed

some peculiar markings in the land they were excavating: distinctive patches of reddish-orange

sediment.

This wouldn’t have been all that exciting, except that those patches looked a lot like

the patches of baked earth left behind by the campfires made by modern people in the

area.

Interestingly enough, this site had also turned up the jawbone of a fossil hominin and evidence

of stone tools having been made there, about 1.6 million years ago.

So this got the researchers thinking: Was it possible that these red patches were the

signs of an ancient fire that was used by some of our distant ancestors, more than a

million and a half years ago?

Well, maybe. There are still some big questions to answer.

Like, could the hominins at this site have actually made fire? Or did they happen to

find some fire occurring naturally, like from a lightning strike, and just used it for as

long as they could?

It’s likely that our ancestors started out this way, taking advantage of fire as a fleeting

natural phenomenon.

But eventually they took it one step further-- scavenging a burning twig left behind by a

wildfire, and using it to start their own fires.

The use of fire wouldn’t become truly visible in the archaeological record until it became

widespread - when fire started to be used consistently, across many different sites.

This could’ve been the moment in our history that sparked evolutionary change, triggering

an expansion into new environments.

And when we learned how to actually make fire when we wanted, it would forever change

our relationship with the world around us.

Now, the fact is, we don’t know exactly when hominins harnessed the power of fire.

And we’re not totally sure what species among our ancestors was the first to master

it -- although there’s one candidate that seems most likely. And it wasn’t us.

Nevertheless, we do know that the ability to make and use it has fundamentally changed

the arc of our evolution. The bodies we have today were, in many ways, shaped by that time

when we first tamed fire.

The use of fire in human history is notoriously difficult to study, because fire is ephemeral.

It’s more difficult to see in the archaeological record than, say, stone tools, because it’s

a transient phenomenon that leaves little evidence behind. Ashes can easily blow away

in the wind or be washed away by water.

But we know that the use of fire has had enormous impacts on our bodies and our behavior.

So some experts have looked at the gradual changes in how hominins looked, and how they

lived, to hypothesize which of our ancestors may have mastered it.

The first impact that fire has had on our evolution is that it allowed us to cook food.

And it’s hard to overstate how important that was.

The main advantage of cooking is that it breaks down food, making it easier to chew and digest.

You can actually think of cooking as a way of starting the process of digestion, before

you even put the food in your body. Which sounds gross when I put it like that.

It's actually delicious

But heat causes the large, complex molecules in food to break up into smaller, simpler

nutrients.

So if you heat food with an external source of energy, like fire, then you’re saving

the energy that your body would have to put into chewing and digesting the food if you

had eaten it raw.

Cooking also breaks down toxins in plants and kills pathogens. And again, this saves

your body from having to invest energy in defending itself from poisons and disease.

Together, these things make cooked foods much more energetically efficient than uncooked

foods, so you end up getting more calories out of what you eat. And when you’re trying

to survive, every calorie counts.

But of course, the other advantage of fire is that it like … keeps you warm. And so the

use of fire likely helped our ancestors expand their geographical range, migrating to places

with different climates and opening up a whole new world of ecological possibilities for

our species.

Now, there’s one hominin, besides us, that fits both of these descriptions -- a species

that needed a lot of calories and that had to live in lots of different environments

-- and that’s the earliest definitive member of our genus, Homo erectus.

Some anthropologists propose that Homo erectus might have been able to cook food, based on

its physical adaptations.

Specifically, it had smaller teeth than its predecessors, suggesting that it didn’t

need to do the heavy-duty chewing that a diet of raw food would require.

But maybe more importantly, it also had many of the traits that we know require a lot

of calories -- like a larger body size, more muscle mass, and most importantly, a larger

brain.

And as for its ability to live in different environments, Homo erectus is the first hominin

known to have migrated out of Africa, eventually spreading from what’s now the Republic of

Georgia all the way to Southeast Asia.

But here’s the problem: Homo erectus dates back about 1.89 million years.

But the earliest possible evidence of repeated, regular cooking doesn’t show up until hundreds

of thousands of years after its appearance.

Likewise, Homo erectus began its excursions out of Africa hundreds of thousands of years

before the first definitive evidence of widespread fire use.

So how could fire have helped this species develop a bigger body and brain, and help

it migrate to other places?

Well, as in many aspects of studying the distant past, there are a lot of dots to connect.

And in this case … we’re just missing a lot of dots.

So let’s look at what the evidence does tell us -- about the use of fire in general,

and then cooking specifically.

In the past few years, anthropologists have gone back to that red-stained site in Koobi

Fora, Kenya. And recent excavations have turned up more definitive evidence of fire use than

those red patches of earth found in the 1980s.

Archaeologists have discovered shards of rock with tell-tale signs of having been heated

to high temperatures, as well as bits of burned animal bone.

And these bits of rock and bone seem to be clustered in distinct patches. Which is important,

because it suggests that the fires were small and made intentionally, and not a natural

wildfire, which would have burned across the whole site.

As for who made these fires, the burned rocks and bones were all found in an area associated

with artifacts that were likely made by Homo erectus.

But there aren’t any remains of those hominins to be found there. Instead, the only hominin

fossils from the site are of Paranthropus boisei, a smaller brained species.

The next earliest site with /widely-accepted/ evidence for fire is a site in South Africa

that dates back 1 million years, in a place called Wonderwerk Cave.

There, archaeologists have found burned bones and plants, as well as the larger and more

complex stone tools, like hand axes, that are known as Acheulean tools.

These tools have often been associated with Homo erectus. And some experts have speculated

that, based on the date as well, Homo erectus may be the hominin that built those fires.

Other more recent evidence of fire has been found at a site in Israel called Gesher Benot

Ya’aqov.

And there, at a site that’s about 790,000 years old, burned seeds, wood, and flint have

been found clustered together into what researchers call phantom hearths - areas where fire might

have been, but without a neat campfire ring of stones.

These clusters, and the fact that they occur throughout time at the site, suggest that

the hominins who visited there were very familiar with fire and could create it any time they

wanted.

Again, no hominin fossils have been found there, but Homo heidelbergensis, a large-brained

species that might’ve been the last common ancestor of humans and Neanderthals, is one

candidate.

So that’s what we know about when hominins used, and maybe made, fires. But things get

even more interesting when we try to figure out which of our ancestors was the first to

actually cook with it.

Those bits of burned bone found at Koobi Fora aren’t necessarily proof that hominins were

regularly cooking meat 1.6 million years ago.

Instead, as with fire use in general, anthropologists are much more interested in when cooking became

widespread enough to actually influence our evolution.

And evidence for regular cooking behavior doesn’t appear until very recently, at least

in geologic terms -- about 350,000 to 400,000 years ago, in the region of the Eastern Mediterranean

known as the Levant.

Here, another cave site, called Qesem, preserves a large, central hearth that was used repeatedly,

and which one group of researchers thinks was commonly used for roasting meat.

Hominin teeth found in the cave resemble those of both Homo sapiens and Neanderthals. But

whoever was cooking at Qesem, they left behind lots of butchered and burned bones.

Finally, there’s still the question of when and where fire was used outside of Africa.

If fire was so helpful in fueling human migration, then can we track its use around the world,

to retrace our steps?

Well, the first species that we have fossil evidence of outside of Africa is -- you guessed

it! -- Homo erectus, at a site called Dmanisi in the Republic of Georgia, which dates back

1.8 million years.

But there’s no evidence for fire at the site, even though winter temperatures likely

got just slightly above freezing.

And again, as with cooking, we only see really solid evidence for fire use in colder climates

much, much later -- at around 400,000 years ago in Europe, at two different sites.

At Beeches Pit in England, areas of burned sediment with heated stone tools and burned

bone have been interpreted as the remains of hearths. And at Schöningen in Germany,

the evidence is heated flints and charred wood.

These two sites have been suggested to be the work of Homo heidelbergensis, the same

potential fire-maker from Gesher Benot Ya’aqov.

But there are a lot of other hominin sites, both open-air and in caves, scattered across

Europe that /don’t/ show evidence of fire, even though winter temperatures there couldn’t

have been comfortable without it.

Those hominins must have found other ways to cope - maybe through other cultural adaptations

like clothes and shelter, or just cuddling a lot

or by migrating - being the Pleistocene equivalent of today’s

snow birds.

So the origins and spread of fire in our evolutionary history remain full of paradoxes.

Like, how did Homo erectus evolve to have such a large brain and body without the bump

in energy and calories gained by cooking?

We see these changes in the anatomy of our ancestors before we see evidence of fire in

the archaeological record - though some researchers have suggested that we didn’t need fire,

just good cutting tools, to start the process of breaking down meat before consuming it,

allowing us to efficiently extract more calories.

And how did this same species migrate out of Africa and into colder climates without

the warmth of a campfire? Dmanisi in the Republic of Georgia has a wealth of fossils, but no

signs of fire.

It seems pretty likely that the first fire made intentionally, by the hands of a hominin,

sparked to life somewhere in Africa, probably in an open-air site like Koobi Fora.

And maybe those hands belonged to a member of Homo erectus.

As with many other early chapters of our history, we have a lot more research to do.

But each of us lives with the legacy of that moment, captured in our own bodies. Our size,

our musculature, and our big, clever brains, are all influences from that time -- somewhere,

by someone -- when we first tamed fire.

Thanks for watching this episode of Eons, which is produced in partnership with PBS

Digital Studios and Complexly.

Complexly produces over a dozen channels, including Nature League, where host Brit Garner

explores life on Earth and questions what we think we know about the natural world.

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the description below.

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