5: The Genus Homo

5:  A New Genus Evolves: The Homos

 

Our genus, the genus of the currently living members of the human race, is ‘homo.’  The term ‘genus’ means a ‘generic name’ and is a general name that is used to refer to a category of beings that all seem similar.  It really has no scientific meaning and is used only for general classification to help people understand the general category of beings referred to.  The term ‘homo’ is often used synonymously with ‘man' or ‘human’ but it is a generic term that basically means ‘man like’ (or ‘human like’) beings.

The earliest members of the homo genus that have been classified are the Homo egasters.  This term is often translated as 'the working man.'  (egaster is Latin for ‘working.’)  This name was coined because these were found around large numbers of assorted tools, making researchers think they were dealing with people who liked to work and make things. 

Homo erectus is often translated as ‘the upright man.’  This came from its posture, dramatically different and more upright than its pan ancestor.  Some researchers think homo erectus and homo egasters are different subspecies of the same species, while others think they are in different species.  Some think that they may not even be different subspecies, but merely different members of the same species and subspecies that happen to look different.  (We don’t all look the same.)  We don’t have any DNA from these beings, so we can’t verify the claims.  They aren’t really important for the points here:  All that matters is that there were early human-like beings that had this classification.  Large numbers of fossils have been found both in Africa and in Asia.  

These people traveled a lot.  (I will take the liberty of using the terms ‘people’ to refer all members of the genus homo.  The main reason for this is that I need something to call them in discussions and this seems more appropriate than any other name I could find.) 

Homo habilis is ‘the tool using hominid’ or ‘the tool using man.’  Homo neanderthalis and homo denisova are named after the sites where their remains were first identified.

Homo sapiens means ‘the intelligent hominid’ or ‘the intelligent man.’

Until very recently, this term was used to refer to ‘our’ species, where ‘our’ refers to ‘the people who are now classified as humans and the people with similar levels of intellect who lived in the past six thousand years.  Those who believed that history went back more than six thousand years thought that the beings who lived before this period were in some other category, at least in a different species but possibly in a different genus. 

 

A family of religions called the ‘Abrahamic religions’ is built on a set of books called variously by names like the ‘Books of Moses’ and ‘the Pentateuch and the Torah have been and still are important religions in the world, claiming more than 57% of the world’s people as followers, and include Christianity, Judaism, and Islam.  All Abrahamic religions teach that nothing existed before a certain date (October 23, 4004. B.C., according to James Ussher, who claims to have worked it out in detail). 
          For many centuries, the Abrahamic religions controlled state apparatus in large parts of the world and required all followers to accept this story on pain of death.  People couldn’t do research into events that they thought occurred before this date, because that would subject to them to arrest, execution, and confiscation of all their property by the state. 
          We will go over this period in history later in the book.  The ban on analysis faded away fairly slowly (or so it appears to us who lived through time) as more and more evidence showed it had to be wrong and religious authority faded.  But as recently as a century ago, teachers in the United States could be arrested for implying the chronology was wrong under the Butler Act, which prohibited certain teachings that were inconsistent and many countries today still have laws prohibiting providing children with inconsistent information and, while it isn’t strictly illegal, many jurisdictions go to great lengths to discourage this teaching.     

 

Not everyone accepts the scientific evidence, even today. 

But most educated people accept at least the premise that he universe is a lot older than 6,030 years old.  There still seems to be a lot of resistance to the idea that humans (meaning true humans, including homo sapiens) go back more than 6,030 years.  DNA evidence is showing us, however, that the species homo sapiens definitely goes back a very, very long time, because human-like beings that were once thought to be different species, like neanderthal and denisovans, clearly had babies with beings that were anatomically and genetically indistinguishable from modern humans.  This means that all three of these groups, thought to be different species, are actually the same species. 

Let’s look at the evidence we have that can help us understand the background of the genus homo (human-like beings). 

 

The Genus Homo

 

The earliest specimen of the genus Homo found to date (as of 2024) was found in the Ledi-Geraru site in the Afar Region of Ethiopia, in the northern part of Africa, in January of 2013.  It has not yet been assigned to a species as of this writing.  It has been given the designation LD-350.   It has been dated back to somewhere between 2.75 and 2.8 million years BP (before the present).  Several other finds have been made that have been dated to between 1.85 million and 2.75 million years ago.  All finds older than 1.85 million years ago were found in Africa.  We have no evidence of any ‘human like’ beings living anywhere outside of Africa before 1.85 million BP (before the present). 

This seems to indicate that the genus homo originated in Africa.  It also indicates that the members of this genus who left Africa did so some time before 1.85 million years ago, but probably not much before this, or we would have probably found signs of this.  That means that we can date the exit of humans from Africa to about 1.85 million years ago. 

 

What Are Homos?

 

The main difference noticeable between the Pan genus and the Homo genus is brain size.  We don’t actually have brains of early homos for comparison, because brain tissue decomposes quickly.  But we can tell the brains of the members of the homo genus were much larger than the brains of the members of the Pan genus by measuring the brain cavities in remains. 

The brain cavities of the earliest adult homos are about twice the size as the brain cavities of adult pans.  The brain cavities of adult modern humans are about three times the size of those of adult pans. 

I think it is important to try to get some idea how this particular change happened, because large and complex brains are basically the defining features of humans. 

We got these large brains somehow. 

In other words, they evolved for some reason.  

After we got this higher ‘processing capability’ we could use it for many different things.  We now use it to study things, solve problems, and build fantastic machines and equipment.  But if we want to understand why we are what we are now and how we got here, we should at least try to get some idea of the reason that these large and powerful brains were needed. 

 

Fire

 

There seems to be a very obvious explanation for the massive increase in mental processing ability:  The pans who lived in a certain very specific area got a new toy. 

Actually, it was a tool. 

But it is really fun to play with and most of us play with it, in one way or another, nearly every day.  (If you drive a fossil fuel powered car, you are playing with it:  the fire is in the cylinders.)  It has so many uses that, even after having had it for at least three million years, we still haven’t figured them all out yet. 

Fire is such a complicated tool/toy that the pans who had access to it couldn’t understand it and use it effectively with the smaller brains they had when they first found it.  Over the course of millions years, different individuals had different genetic profiles (every one is unique) and different mental capabilities. 

Some had just a little bit better capability to understand and use fire than others. 

They could do things the others couldn’t.  They could meet the needs of their babies when others couldn’t.  They passed their mental advantages down to the next generation and showed them tricks they could do with this new toy that others didn’t know how to do.  Those that succeeded had greater chances of survival than those that didn’t.  Over long periods of time, the percentage with genes that encouraged larger brains to grow increased and the percentage without these genes declined. 

This led to what we may think of a ‘supercharging’ in the evolutionary process.  In the area where this new toy/tool was available, progress was incredibly fast, at least relative to places where fire was not available.  The growth in intellectual capability was so profound that, within a million or so years, the beings that had the use of this new toy/tool had changed almost everything about the way they interacted with the world around them. 

They weren’t as smart as we are now.  But they were far, far smarter than the pans that were their evolutionary ancestors, and so different that reasonable analysts would not consider them to be the same genus.  They were a different genus, the ‘homos.’ 

 

Fire

 

Fire is mesmerizing.  I have sat and watched wood fires for hours, staring into the flames.  It has many uses.  I cook with it, heat my house with it and, when the electricity goes out I have candles I can light to see my way around.  Gasoline engines use controlled fire, setting gas air mixture ablaze in conditions that lead to a rapid burn called an ‘explosion,’ which is then repeated over and over to make the wheels turn.  Jet engines use fire, as do rocket engines.  Guns ignite a highly flammable powder to create an explosion that drives a bullet.  Armor piercing uranium bullets explode and burn on impact in a way that melts steel and turns it into a liquid.  The bullet then cuts through what had been several inches of solid steel as if it were butter, into the center of the tank, where it hits oxygen that causes the liquid metal debris to explode again to kill everyone inside the vehicle. 

Fire is very complicated.  It takes different skills and different mental connections to figure out these uses than it takes to find bananas and other food in forests.  The animals still needed the brain components they used to find food and meet their other needs. But those that could expand their brain and direct its activities so that it could do these other things had fantastic advantages over those who couldn’t. 

To use fire effectively and safely, you need to be pretty intelligent.  If you are stupid and you take risks with fire, you will not live very long.  If you are smart and use fire well, you have incredible advantages over beings that are otherwise the same as you, but don’t use fire.  They are primitive beings compared to you.  

The transitions from ‘primates that don’t use fire’ to ‘primates that do use fire’ is a critical one in the human experience.  I really couldn’t find any scientific analysis, even speculative analysis, that showed how this key event took place in the literature.  But you understand a little bit about the geography of Africa, the domains of the pans, and the way that oil pools above fields with great pressure and then catches fire from natural events, you can get a pretty good idea where and how it is likely to have happened. 

The descriptions below are speculative.  But they are only designed to fill in some important holes in the way we look at ourselves and our past.  These exact events may not have happened, but something similar did happen.  We can understand a process a lot better if we can put a picture of it together in our minds.  I want to describe the picture for you:

 

Unity

 

First let’s set the scene:

Let’s consider again the picture of Africa taken from space. 

 

Africa from space

Africa from space, taken from Google Earth.

 

The central area, right around the equator, is where the Nile river begins.  The clouds that circle the globe at the equator are trapped by something called an ‘Intertropical Convergence Zone.’   They can’t go north or south, they can only circle until they have so much water in them they just can’t hold it anymore. 

When they hit the high mountains in Tropical Africa, the Rwenzoris, they have to go up.  The air is cooler up there and as the clouds cool, they release moisture as rain.  The rain falls and falls, constantly, often in torrents.  The rain flows across the land and comes together as rivers that fill massive valleys, which become lakes.  The lakes overflow to form new rivers that flow into other lakes.  The water fills all of the valleys and every nook and cranny that can hold water.  Then, it has nowhere to go but down.  It starts to flow down the rugged mountains into the foothills below.  It collects, at the base of the mountains, into one of the two main tributaries of the Nile, the ‘White Nile.’

As the land levels out in the northern part of the green zone of the picture, the White Nile becomes a lazy river.  The low land doesn’t drive the clouds up to cause rain in these areas, so the land becomes drier and drier.  At a certain point, the land turns bone dry and there is no plant growth at all.  (The moisture is trapped in the Intertropical Convergence Zone.) 

The river now enters the Sahara desert, where it provides a ribbon of life that extends more than 2,000 miles all the way to the Mediterranean Sea. 

If you follow the White Nile river down to just before the green disappears and you enter the desert, you would be in a state called ‘Unity.’  It isn’t really possible to tell what country the state of Unity is in, because it is disputed and several countries claim it today.  But they all call it ‘Unity.’   This is the site of the unity oil field. 

It is truly massive field.  It has underground reserves of 3.5 billion barrels of oil.  (This may help you understand why so many people are fighting over it.  The war over Unity doesn’t make the news very much, possibly because news shows don’t cover wars that involve black people fighting other black people.  But it is one of the largest and most deadly conflicts on the planet as I write this.)  

The underground oil deposits are under fantastic pressure from the weight of the land above them.  this pushes the oil up from the underground deposits to the surface.  It flows up and forms pools at the surface. 

These pools have been there for a very long time.  Ancient Egyptian texts discuss the transport of this oil down the river to Giza, the site of the pyramids, so that the builders could use it for light, for lubrication (oil a flat surface and you can easily slide something weighting several tons across it), for cooking, heating, and making medicines.   This oil was there when the pan genus evolved 6.7 million years ago. 

Once oil gets forms pools, they oil starts to stratify.  Heavy oils like tar and asphalt sink to the bottom.  Lighter oils like methane, ethane, propane and butane, rise to the top.  The first two are lighter than air and float up into the sky.  They mix with oxygen on the way, creating a very explosive mixture.  A tiny spark anywhere will set the entire thing on fire.  The other light oil products float partly as gasses and partly as liquids on the top of the pools.  These burn easily and keep burning as long as there is fuel to feed them.  With 3.5 billion barrels under the ground, they will never run out. 

Before humans, these surface pools were scattered all around the area near the current Unity Field.  Unity state is on the border between two climate systems.  The rains come in thick during certain times of the year.  Plants grow very rapidly.  Then there is no rain at all for months.  The plants all dry and become tinder dry.  Electrical storms are common in all climactic convergence zones:  rapidly rising water vapor strips electrons from the air, creating electrical charges.  Lightening equalizes these charges.  Lighting ignites the wild dry grass which burns like, well, wildfire.  The fires hit the pools, large and small, and ignite them all. 

The larger fires wouldn’t have been attractive to the pans.  Large fires create their own climate systems with howling winds that result from the intense temperatures.  The fires are hot enough to partially burn the very heavy hydrocarbons like asphalt and tar, which produce a thick black smoke.  They would have stayed away from these fires.

But the small pools of gasses and oil would be much different.  You can go to restaurants today, in areas with cold climates, that have outdoor patios. 

 

Buring Oil Pool

Burning Oil Pool

 

 

They run propane through rocks in a little fireplace and set it on fire.  It is very comfortable to be around these fires and I enjoy coming to these places to get a drink or something to eat.   

 

The Pans Arrive in Unity

 

For millions of years, pans were the smartest beings on Africa.  They were able to dominate other animals and take what they wanted.  If an area had food that could support pans, and they wanted it, they could take it.  The green area in Africa is very large and can support enormous populations.  But, given enough time, even these enormous areas would get crowded. 

The territorial pans, the chimps, would move out and colonize new territories when their lands got crowded.  The White Nile goes through very productive land all the way to Unity.  It probably took hundreds of thousands or even millions of years, but eventually, communities of chimps would have lived on land that was close to the fires. 

The non-territorial pans probably got there first.  They were comfortable with traveling and felt at home wherever they went.  They didn’t need rich land and were accustomed to working for whatever they got.  Then the territorial pans arrived, and made it clear they were willing to kill, if necessary, to monopolize the best lands, the non-territorial pans moved on.  But both lived in this area as of 3 million BP (before the present).   

They saw the fires from the burning oil pools. 

The members of the pan species are very intelligent.  Other than humans, no other animal can use tools better or make better use of the things they see around them.  There are uses for fire, even if you don’t know how to make it or move it from place to place.  Fire provides light. 

Pans, like humans, have poor night vision. 

Their predators (lions, saber toothed tigers, wolves, to name a few) have excellent night vision.  Pans that are in total darkness will be helpless against these predators.  They will be a lot safer if they can find a place where there is a natural fire (a relatively small burning oil pool) and make their camp close enough to use its light to see predators coming.  To the territorial pans who had carved out the best land for themselves, it provided great benefits.  If they could camp close to fire, they could see their enemies coming and organize to fight them.  They couldn’t be attacked by surprise, at least not as easily, if they had even a tiny bit of light. 

As the pans spent more time around fire, they became more and more comfortable around it.  Fire is mesmerizing.  I like to watch it and think about how it moves and dances around the fuel.  I start to see patterns.  I don’t try to apply any logic or reason to it, I simply watch.  Eventually, I can start to see where the flames will dance off to next. 

Primatologist Jill Pruetz at Iowa State University in Ames studies the way that pans interact with fire.  When dry seasons come to parts of Africa, wildfires burn everywhere.  Preuetz notes that the chimps appear to be far more comfortable around the fires than humans.  They have to live with them several months out of the year.  They know that if they take certain precautions, they will be safe so they don’t panic like other animals, including humans.  Here she describes it in an interview with LiveScience.com: 

 

"It was the end of the dry season, so the fires burn so hot and burn up trees really fast, and they were so calm about it," Pruetz said of the chimps.  "They were a lot better than I was, that's for sure."

For the most part, wild animals consider fire very distressing, but the chimpanzees showed no sign of stress or fear with the wildfires, other than calmly avoiding the fire as it approached them.

"I was surprised at how expert they were at handling the fire," Pruetz told LiveScience.  "The fire was burning really hot, and the flames were at least 10 feet high, up to 20 feet at times."

The apes were experts at predicting where the fire would go, Pruetz noted.  "I could predict it, sort of, but if it were just me, I would have left," she said.  "At one time, I actually had to push through them because I could feel the heat from the fire that was on the side of me and I just wasn't that comfortable with it."

 

These animals clearly lived around fire for a long time.  As she notes, most animals are afraid of fire, mainly because they don’t know enough about how it moves to keep themselves safe.  (Even humans are in this category).  But the chimps appeared to be smarter than humans in this regard.  They understood fire. 

 

The Intentional Use of Fire

 

Most likely, one of the first intentional acts of fire control involved moving fire from one place to another.  Large pools of oil burn very hot and produce massive amounts of smoke.  They stay lit for decades or even centuries:  There is plenty of fuel and no winds or rain are strong enough to put them out.  The small pools burn at a good temperature and are useful, but they go out with a strong wind or heavy rain.  The early pans may have seen a fire that was too big to be useful and many smaller pools that would be great for them if they could find a way to set them on fire. 

They had seen the smaller pools burning before, but they are not on fire at that time.  But they see that a stick gets into a pool of fire and catches fire itself.  Then the stick may fall out of the fire pool of oil, but keep burning.  They would have seen wood burning many times. 

They would have stared at fire as humans do and watched it. 

They would have seen embers falling to small pools and igniting the small pools.  They would know, from their experience dealing with wild fires in the forests (as described in the text box above) that they can safely move a burning branch out of the way if they stay far enough from the flames.  It may take a long time but, eventually, one of them will take the burning stick and move it to the smaller pool, to create a fire the right size. 

Others will see this.  Pans are copycats.  They copy the things others do.  They don’t have to have schools where they are taught how to safely move fire to copy another pan that has done it. 

But every pan has unique DNA.  Some are smarter than others.  Eventually, one will be born that has mental connections that allow her to safely carry a burning stick from one burning pool to another.  She will have invented one of the simplest fire-using tools, a torch.  Mothers are driven by instinct to protect their children.  Nothing drives them harder.  A torch can allow a mother to protect her children from predators.  If she masters the tool of the torch, her children will live while the children of mot hers who didn’t have the new mental connections will become food for the predators.  She will pass on her intellect, along with the skills themselves, to her children. 

The new brain connection will have come into existence because of a chance change in the DNA of the pan that had it.  The new DNA makes the animal more capable.  Those without it won’t be able to compete and their genes will go away.  Eventually, all of the pans in an area will have the beneficial DNA connection.  They will all be able to move fire from one pool to another, if they have to do this. 

Then, another connection will develop that makes the one with it even more capable.  This process will supercharge evolution.  It is hard to explain the doubling of brain size in a mere 1 million years without incredible pressure and great advantages for the animals that had greater intellect.  But the use of fire seems to be something in this category.  It has so many uses that, even now, some 3 million years into the fire age, we haven’t figured them all out yet.  Each new use for fire requires new mental connections. 

 

Nuclear reactions are a kind of controlled fire.  Do you have the mental connections needed to understand how to build a nuclear bomb? A tiny percentage of the people on Earth even have minds capable of understanding the mathematics needed for this. 

 

The power that comes from higher intelligence, in this situation, is fantastic.  A little bit more intellect means you are a little better at using this tool.  Those with this greater intellect survive while those that aren’t good at using this tool perish.

 

Fire and territorial Societies

 

Fire is useful in war.  Armies that have it can fight at night.  If their enemies don’t have it, their enemies are not going to last long.   Armies with fire can throw balls of burning tar using slings, burning their enemies to death.  (This is still done, in a slightly more sophisticated way; the devices we call ‘napalm bombs’ are essentially balls of burning gelatinized oil which are ‘thrown’ from airplanes onto the bodies of enemies and any who happen to be under the planes.) 

The use of fire changed them in many ways.  It expanded their mental capabilities a great deal.  It takes a lot of intelligence to use fire effectively and safely.  We know that in very young children, the parts of the brain that process this information are not yet fully developed.  Young human children will try to touch burning objects and, if not stopped, can be badly hurt.  The parts of their brains that have a cognitive understanding of the dangers of fire are not fully developed. 

The pans living close to the oil fields developed these brain components over time.  Those with them had advantages over those without them.  They were more likely to survive long enough to have young and then raise them to be adults.  Over time, the better-adapted chimps would be more likely to pass on their genes.  The adaptations would build on one another.  Eventually, the chimps would be so different than any of the original chimps that an objective observer would probably not want to use the same name to refer to them. 

They would no longer be pans.  They would be a new genus, our genus, the homo genus. 

 

Out of Africa

 

Let’s look at Africa again. 

 

Africa from space

Africa from space, taken from Google Earth.

 

If you look closely at the picture, you will see that the green area in the center is essentially boxed in.  It is blocked on all sides and there is no real way to get from there to the outside world.  On the north is the hot and arid Sahara.  On the other three sides are oceans. 

If you look very close, however, you will see a tiny ribbon of green that moves up from the green area and cuts through the great desert.  It is tiny because you are looking at it from 2,500 miles up.  This will be the route our ancient ancestors took when they leave Africa.  It is the Nile river. 

This the only way out.  it is the way our ancestors went when they left Africa about 2 million years ago. 

There were different groups of homos that left Africa.  They are:

 

1.  Homo egaster (the worker man)

2.  Homo habilis (the capable man). 

 

We don’t have DNA from either of these groups.  This means that we can’t do genetic tests to determine if they are two separate species, members of the same species that have different ways of life for different reasons, like the chimps and bonobos.

I think you can see what is coming:

 

Two Different Societies Leave Africa

 

One of these two groups, the homo egaster, left artifacts that indicate that its members were clearly migratory.  We don’t find artifacts of homo egaster or their descendants the denisovans in fixed and well built homes, or in communities with roads and public facilities.  They are not found in desirable areas like fertile river valleys, which could be colonized and turned into ‘countries.’ They traveled in small groups and most of the evidence we have from then indicates they were clearly not ‘living’ in the places where they left artifacts, they were just traveling through. 

They lived in the wild open spaces.  They probably were hunter gatherers, and traveled very long distances following game they were hunting.  Homo egaster are the ancestors of the denisovans, who followed the same lifestyles and who left artifacts in many of the same places.  The denisovans are the ancestors of the modern nomads of Mongolia and Siberia, many of whom live the same general lifestyle, living in portable homes called ‘yurts’ and traveling by dogsled or, if they can afford them, snowmobiles. 

In the places where homo egaster lived, it wouldn’t have been possible to form and defend a specific part of the world as a ‘country.’ For this to happen, they would need a piece of land that is monopolizable.  It must be practical for the people living on the land to build borders and defend them, and the land must produce enough to support them without them having to leave it undefended.  The places where homo egaster lived clearly do not qualify. 

They were like the bonobos, both in terms of disposition and culture.  Of course, they probably would have liked to live in the best areas, where food and everything else they need is plentiful.  But, for some reason, they shunned these areas and stayed in remote areas. 

Homo habilis lived entirely differently.  They formed colonies as they went and built permanent facilities, including very large and durable walls to surround the areas where they lived.  We can study their former habitations because many were built along the banks of the Nile where it flows through the dry Sahara.  It doesn’t rain in many of these areas for centuries, so the dwellings don’t degrade very rapidly.  Their artifacts show they clearly ‘settled’ the areas where they lived.  They stayed there.  They had homes where they slept every night.  They clearly had military forces patrolling the walls: we can find evidence of defensive fortifications that allowed them to rain down fire on their enemies while remaining safe themselves.  They clearly had societies like the chimps, built in the same principle: territorial sovereignty.  The homo habilis divided into groups, each of which took possession of a territory, then treated it as if they had sovereignty over it.  They acted much like the people of the world’s countries do today. 

The homo habilis were the ancestors of the people called the neanderthals.  Neanderthal remains are found in great quantities in Europe.  The neanderthals built the many thousands of city states of ancient Europe.  When later technology made it impossible to defend a small state, larger entities closer to modern countries evolved and many of the smaller ‘city states’ (a state the size of a modern city) were abandoned.  You can find the ruins of their old city walls today, all over Europe.  There are so many of them, that most even aren’t marked and used as tourist attractions today.  They are just left to be destroyed by the weather. 

Both of these early groups of the homo genus left Africa starting about 2 million years ago.  The homo egaster (sometimes called ‘homo erectus,’ although there is no agreement on whether they are the same species) went first.  They were migratory people descended from migratory people.  The homo habilis, with their fixed homes and city states then followed. 

These people had large brains.  They were more than twice as large as those of the pans who were their ancestors.  They used fire for light, heating, cooking, and to help them in the manufacture of their tools.  Since the areas where they went didn’t have naturally burning oil fields, they clearly had figured out how to make fire.  They brought the items needed to make fire with them, wherever they went. 

 

How to make fire: This is easy if you have some light oil, a flint, and a piece of metal that contains iron.  This is how a ‘Zippo’ lighter works: the reservoir has very light oil (‘lighter fluid’ is a very light oil).  This oil is soaked up by a wick.  The wick is placed right next to a tiny piece of flint which is pushed up into a metal wheel by a tiny spring.  The metal wheel is made of steel, which has a high iron content.  Spin the wheel and it scrapes the flint creating a spark which lights the oil-soaked wick.  (The wick itself doesn’t burn and can last for decades; it only holds the oil.) If you don’t have fossil-fuel oil, you can use natural oil from animal fat or extracted from oil-rich plants.
       Early homos could have figured out that the oil was the key part.  Oil and a wick (which can be made of anything) and a spark.  The hard part is actually the iron containing metal, needed to generate a large spark from a flint.  If you know the trick, however, you can find them: there is a certain color of red mixed with orange that indicates a high iron content in a rock.  Look for it and keep trying, striking the rocks together until you get a tiny spark.  (This will happen when you find one with an iron content of about 60% or higher).  Then, once you have the iron rock as a striker, you test it against other rocks.  Each one will give a different level of spark.  Striking flint against the iron rock will give you the best spark.
       The American ‘Indians’ used this method to make fire.  For this reason, they placed great value on iron and one of the most valuable trade goods available to early explorers was simple nails.  (The explored Captain Cook descries the elaborate lengths to which the natives he met would go to get even a single nail.  He didn’t seem to understand why a nail was worth more than a pile of silver or gold.  The higher the iron content, the greater the spark.  His nails were almost 100% iron.)
       Cook traveled extensively and was the first person from Europe to have contact with the people of several hundred islands.  They were all different in many ways, but they all shared one trait: they all used fire.  Cooke noted that the poorest of the people he met had no clothes, blankets, or other comforts, but they would never go anywhere without their fire making kits: 

 

How Territorial Sovereignty Societies Spread

 

Homo habilis, and their descendants the neanderthals, had societies built on the idea of dividing themselves into different teams to fight over exclusivity (sovereignty) over pieces of territory.  These are the same kinds of societies chimps have and the same kinds of societies that dominate the world now. 

These societies spread in a very specific way.  If we want to understand how they developed into the societies we have now, it helps to understand how these systems expand. 

They can start with a few people (or animals; territorial sovereignty societies are suitable for both) in a small area, but spread until they cover immense areas.  These societies spread by the process of ‘colonization.’ When the individuals in a group that has taken control of a territory can no longer support their population on that territory, they find some other territory that will allow them to basically transport a new version of their system to that territory. 

They have a system that requires defendable borders.  Homos are a lot better at fortifying borders than chimps.  They build durable barriers that are very high (many of the border walls in the world are more than 100 feet high, and incredibly well fortified).  These borders can’t be moved so the territory of each of these units is more or less fixed.  If the population grows, the territory can’t grow.  The territory gets more and more crowded expand with ever increasing stress on resources.  Eventually, if additional territory exists, they will send out ‘colonists’ to find it and basically create a new version of their system into that colony. 

If no unoccupied territory that is suitable is available, they will have to try to take over occupied territory.  If the others in the territory are passive and pacifistic, unwilling to fight (as the bonobos were in the chimp/bonobo conflicts), the more aggressive colonists can often drive them away.  If there is no place to move them to, they can simply wipe them, out. 

 

In the book ‘A Short Account of the Destruction of the Indies,’ Las Casas tells how Columbus colonized the formerly densely populated island of Haiti.  The ‘Indian’ population when Las Casas he arrived in 1509 was over 3 million.  Twenty years later it was down to 100 and, by the time he wrote the book in 1542 it was zero.

 

If the all land that is unoccupied and all land occupied by people with pacifist societies has been colonized, the only way to get more territory will be to make war against another occupied area (‘country’) and take it from them.  but this time is not going to come for the homo habilis and their descendants for another 3 million years.  When they first left Africa, there was plenty of land everywhere. 

 

Where They Spread

 

The map below indicates the paths of migration of the more aggressive early members of the homo genus, including homo erectus and neanderthals. 

They came from central Africa.  They went up the Nile.  From there, they spread along the Mediterranean shore.  Some went east to the area now called the ‘Middle east.’ They found the fertile and productive valleys of the Tigris and Euphrates.  They built colonies in these areas.  They continued west along the northern part of the Mediterranean, to modern Greece.  (The inland areas along the Mediterranean east of Greece were not really suitable for colonization without modern technology, because it doesn’t rain enough in these areas to support crops.) From Greece, they spread into what is now western Europe.  The land they found is rich and productive and the homo erectus and neanderthals flourished there. 

The great bulk of the land of western Europe is productive enough to support permanent hominid settlers.  They can plant grains and grow them in the summer.  They can store the grains and grind them into flour, to have bread in the winter.  They can domesticate and feed chickens, ducks, geese, pigs, goats, sheep, oxen, and other animals.  They can have eggs, milk, cheese and butter.  They can live very well. 

Since they live well, their population will grow.  At some point, they will need more land.  The people with the other culture, the homo egaster and denisovans (discussed below) will already be there.  These are migratory people however and have neither the desire nor the ability to fight in a way that might allow them to win against the ones who need the land for their colonies.  At first, the occupied territories will have space between them.  But this space will fill in.  Eventually, the occupied territories, which we may now call ‘states’ or ‘countries,’ will be against each other, with the borders of one the same as the borders of the next.  (This is the way these ‘countries’ are today.) As long as food is plentiful, however, and they have no effective birth control, the population will grow.  Stress will build.  The people who have important positions in each country will look for weaknesses in the defenses of their neighbors.  When they find them, they will attack. 

Their system will work the same basic way as the system of the chimpanzees, with one exception: They will have far better weapons.  The carnage will be far greater than takes place in chimp societies. 

 

Neanderthals, denisovans, and ‘Modern Humans’

 

As noted earlier, sciences are advancing at lighting pace.  They are providing new information that shows that old ideas about fundamental realities of existence were wrong.  Neanderthal remains and artifacts show they were brutal and violent, organizing and participating in horrific mass murder events.  They killed and killed and killed; it was what they were known for.  Their bodies looked something like us, but that was a coincidence.  They were not like us.  We are civilized and reasonable.  They were thought to be the primitive beings that lived in Europe before true humans arrived. 

However, we were told, we don’t have to worry about these horrible monsters bothering us.  They are now extinct and have been for tens of thousands of years.  Or so says every reference I could find to them that was written before about 2020.  Modern humans arrived at some point, only a few thousand years ago.  (Religious people are stuck on the figure of about 4,000 BC, the time given for creation in the Bible.) The neanderthals couldn’t compete with the logical, reasonable, empathetic and entirely civilized beings that we are. 

Denisovan remains were found far more recently.  They were not savage fighters, but they appeared to lack ingenuity and the normal curiosity of modern humans.  They were hunter gatherers, not even intelligent enough to build permanent cities or form governments.  They are also extinct.  These simple beings simply couldn’t compete with the wise, noble, and cultured beings that WE are. 

DNA evidence has shown that this is wrong.  All modern humans tested so far show some neanderthal DNA, some denisovan DNA, or both.  They are not extinct.  We are them.  DNA also shows that many babies were produced with one parent that was neanderthal or denisovan, and another parent that had a DNA profile and anatomical features indicative of a modern human.  This meant that we are all the same species.  They are not extinct.  They are still here.  We are them. 

You can have your DNA tested.  The testers will tell you your ancestry.  If you have any European ancestry, you will have neanderthal DNA.  If you have Indonesian, or American native ancestry, you will have denisovan DNA.

It is important for us to realize there is no hard line between us and our evolutionary ancestors.  Not between us and neanderthals/denisovans (which were, remember, the same species), not between us and the homo egaster/homo habilis (which may have been the same species) and not between us and the pans (two species, two different subspecies).  Evolution is a slow process.  Each change is tiny.  But the changes accumulate, one on top of the other.  We go from pans who live around fire to members of the homo genus that have brains that are large enough and powerful enough to actually understand how to use fire.  This didn’t happen overnight.  It took more than a million years of mental growth to get to that point. 

Fire is a very complicated thing.  We are still not fully in control of it.  It has uses that we still haven’t found, after three million years living with it.  But it is so powerful and so useful that nature was able to push through aside other adaptations to give animals that have the ability to use it priority over others.  A doubling of the brain size was necessary to make this work.  But nature was patient and, over the course of a million years, this happened. 

New brain connections were needed for this.  Each newborn was genetically unique, with its own DNA profile. Some had genes that made them more able to make these connections and form additional brain material to hold them.  These children grew up to be a tiny bit smarter than their parents and the generations that came before them.  The smarter ones had a better ability to deal with key tools and otherwise meet their needs.  They had a greater chance of survival than others and were more likely to survive long enough to pass on their genes to their young.  There are more than 3 billion connections in our DNA.  A single link of difference, which could be the result of a mutation or a chance inheritance that had simply never happened before, could make a difference in this area.  The generations get smarter and smarter.  Not in any way would notice in just a few hundred years.  But if you could come back and visit the beings living alongside of the fires near Unity once every thousand years, you would see a difference. 

Eventually, they were so different that people who are now studying their remains would want to put them into a different category.  They have to have something to call them.  So they come up with names, like homo egaster, homo habilis, neanderthals, and denisovans.  Until we had the ability to do large scale DNA analysis, we couldn’t do anything more than guess about the relationships.  Now we are finding that we can test relationships in detail.  This is showing that the differences aren’t really that great. 

We don’t have DNA from homo egaster or homo habilis (the presumed first steps in evolution from pans to humans), so we can’t test them.  We only know that beings with much larger brains than pans evolved in northern parts of Africa and eventually spread to the rest of the world.  We do have DNA from both neanderthals and denisovans and we know that they are the same species as we are.  We don’t look the same as they look.  You probably wouldn’t have a very satisfactory conversation with these beings and, if you considered them to be human at all, you would probably consider them to be very stupid humans.  But if you were in the right situation and mood and had sex with one of the opposite sex, the female could get pregnant and eventually give birth to a child that was healthy and fertile. 

Here is the point: there is no hard line.  We are them and they are us. 

 

Keywords    Human evolution, Homo genus, Early hominids, Fire use in human evolution, Out of Africa theory, Homo habilis, Homo erectus, Neanderthals, Denisovans, DNA evidence in evolution, Brain size evolution, Territorial behavior in early humans, Human migration patterns, Prehistoric tool use, Ancient human societies, Human ancestors, Evolutionary biology, Paleogenetics, Human origins, Prehistoric fire control

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