We’ve conquered every terrain, climbed every peak, and explored the ocean depths. There’s practically nowhere on this planet that people don’t live. We’ve built mega-cities, dammed vast rivers, and drilled deep below the surface of the Earth. Yes, humanity’s colossal impact on the globe can’t be denied: for good or ill, we’ve reshaped vast swathes of our environment. Yet while there’s not a lot of debate about our dominance as a species, the reasons behind why we’ve managed to become so preeminent are less obvious – and you might be surprised by one theory that scientists have developed.
“Dominant species” is a term you might have often heard used by ecologists. It means that there’s a particular type of animal (or plant) that isn’t only particularly plentiful in a certain environment but also has a disproportionate impact on the other living things around it. If you remove the dominant species then it means change for the entire ecosystem.
For example, when it comes to the deserts of North America, then one dominant species is the kangaroo rat. It’s well adapted to the hot, dry conditions with its ability to save water by not sweating. If it does encounter a threat then it may jump an astonishing 9 feet in the air to escape. It’s no wonder it’s abundant, but it’s also essential to other species because it helps spread plant seeds and is a plentiful supply of food for various predators such as snakes, owls, and coyotes.
Humanity doesn’t only dominate the desert environment, though, nor just forests, grasslands, or seas. Humans are an abundant and influential presence in every corner of our planet. Yes, insects are prevalent too in a rather different fashion, but we’re ubiquitous in a way no other large animal can claim. That’s quite astonishing when you think about it.
Everywhere Except Antarctica
We’ve built thriving civilizations amid arid deserts and cleared countless trees to turn into our farmland. Every continent except Antarctica is packed with roads and cities and humans, and even Antarctica has a research station or two. It’s no wonder that scientists like to question just how we managed it.
Researchers From Every Country
This particular theory as to how we’ve managed it is the culmination of lots of research by biologists, anthropologists, archaeologists, environmental historians, and even neuroscientists. They come from the USA and the U.K. among other countries and are based in prestigious universities such as Harvard and Vanderbilt as well as institutions like the Smithsonian.
Understanding Every Aspect Of Humanity
Such a diverse range of experts is needed for this kind of theory because it has to involve an understanding every aspect of humanity, from our biology to how we build our societies. It needs to look at our history over hundreds of thousands of years to figure out not just how we have evolved, but why.
It not The First Time
It’s not the first time scientists have tried to identify a definitive reason for humanity’s dominance. Past theories have focused on everything from how we communicate to our use of tools to the way we pass on knowledge. Each of those things can be used to show how we differ from other animals, even our closest relatives such as chimpanzees.
Communication Is Important
For instance, as far as we know there aren’t any animals who communicate in the complicated ways humans do. We don’t just have a few sounds but whole languages that we have to learn as we grow, and that evolve over time to take in new concepts and inventions. This allows a huge diversity in human expression.
Using it Right
Humanity uses its communication skills to reference and learn from the past as well as planning ahead for the future. Communication is also a tool of cooperation that makes it easier for us to work together. We take down predators much bigger than us and build things that our ancestors would have thought impossible because of our social bonds, which are facilitated by communication.
Cooperation is another of the behaviors that helps to set us apart. There are animals that hunt in packs, but the way humans have organized themselves is something different. We have complex codes of morality and responsibility that enable us to establish societies where everyone is expected to participate and the penalties for diverging can be harsh.
Our closest rivals for global dominance may be insects and other creepy crawlies. They’re certainly the most prevalent creatures in terms of sheer numbers, with an astonishing importance to vital things like the composition of soil. Of course, if we expand our definition to include all living things, then the countless plants growing in that soil provide most of the essential oxygen animals need to survive.
Adapting To Change
Yet what sets human societies apart is how they adapt to change. Even the advanced cooperation of species like bees and ants is limited to narrowly defined roles. When there’s a new threat to the hive or colony then they don’t know how to cope. All this suggests that an unusual degree of creativity also contributes to human dominance.
Then there are tools. We’ve all seen the start of 2001: A Space Odyssey, right? Very little of what humanity has managed to achieve would have been possible without the devices we use to aid building, farming and our general survival. We know that our ancient ancestors started using stone tools millions of years ago when they would sharpen the edges to help kill and prepare meat.
Evolution Of Tools
As humanity continued to evolve so did our use of tools. Woodwork meant we could shape boats and oars for travel and even build homes and furniture. Metalwork was a huge step forwards for human society in general, but particularly in warfare. Even today we still rely on hand tools for everything from food preparation to DIY.
Understanding Of The Animal Kingdom
One feature of our changing views of the reasons for human dominance is how our understanding of the animal kingdom has also developed over time. Things that were once thought to be solely the domain of humans actually turn out to appear in other species, especially in our close relatives among the apes. Intelligence, emotion, communication and tool use are all behaviors which may be more present in animals than originally thought.
Not Limited To The Primates
There are animals that use tools and they’re not just limited to our primate cousins. Otters use rocks to break open mollusk shells when looking for dinner. Dolphins brush the seabed with marine sponges to stir up potential food, and octopuses have been known to don armor made from coconut shells. Apes such as chimpanzees and gorillas are among the cleverest though, with tools that function as everything from weapons to walking sticks.
Learning To Use Them
Both communication and tools would be far less useful if we couldn’t learn to use and improve them. Our capacity for adaptation and the development of educational systems are ways in which each generation of humans can be more dominant than the last. The concept of collective learning is one that has taken a prominent role in discussion of human evolution.
Collective learning is just a fancy term for describing how generations of people pass on knowledge. It’s what allows us to continue to innovate and become more efficient. That in turn allows the population to expand further and overtake other animals. It’s related to biology but it’s not just about the genes we pass on. It’s also about culture and the ideas and attitudes that underpin our development.
As you can see, the factors that influence human dominance are complicated and span several different fields of academic study. This latest theory is no exception and actually requires a look at various aspects of humanity. It starts with what actually seems like a pretty simple thing, and that’s the mastery of fire.
Power Over Fire
Disney fans may remember a certain orangutan singing about how he wanted Mowgli to teach him the secrets of “man’s red fire” in The Jungle Book. And there’s no doubt that power over fire has always been seen as something special and rare, with humanity long recognizing the importance of fire to its success. For one such example, just consider Ancient Greece’s creation myth Prometheus.
According to legend, Prometheus stole fire from the Gods and gave it to humans, which allowed them to build their civilizations. Many ancient cultures have similar myths. It is fire that brings protection from the dark and cold, as well as predators. It’s also useful when doing things like forging tools and weapons. Yet this latest research focuses on another of its less obvious benefits.
A Huge Effect
Fire is what we use to cook food and believe it or not, that may have fundamentally changed human biology. As Harvard University’s Professor Rachel Carmody put it, “Anything that allows an organism to get energy more efficiently is going to have huge effects on the evolutionary trajectory of that organism.”
How Cooking Helped?
We might have to take a look at what cooking actually does to really understand what that means. You probably know that food is made up of a bunch of different nutrients like protein and carbohydrates. It can take quite a lot of effort for the human digestive system to break down these nutrients into a usable form.
Raw Vs Cooked
For instance, have you ever tried to eat a raw potato? If you have you’ll probably agree that wouldn’t be your first choice of food, despite it being loaded with valuable starchy energy. The challenge is particularly great because humans do not have the biggest jaws in the animal world. We can’t easily crunch raw, hard vegetables between our teeth.
Not A Good Idea
Even if we could live off a diet of raw food alone, that doesn’t mean it would be a good idea. Humans who don’t cook their food tend to develop other health problems. It can even stop women who menstruate from bleeding regularly, which is often a sign that pregnancy will carry increased risks for their wellbeing because they may not have enough energy for mother and baby to survive.
Heat Makes A Difference
That’s when heat makes a difference. It starts the breaking-down process before you even put the food in your mouth. Your teeth and enzymes don’t need to work as hard, which means that you’ll be receiving all the good nutrients in a much quicker fashion. It’s a much more efficient and reliable way to eat.
Much More Energy
Now you’re probably wondering why making the digestive process so much more efficient has such a big impact on our overall development. Well, to start with, it means we have much more energy to grow and adapt. In particular it means that our brains can increase in size, which means more neurons, more connectivity, a higher cognitive capacity and eventually more intelligence.
Brain size is another way in which we are distinctly different even from other apes. It allows more planning and invention, but it also means we need more energy to keep it fueled. For early humans this meant figuring out better ways to hunt animals and find – and later cultivate – plant foods. That in turn gave them more opportunities to eat, and to develop new cooking methods.
Growth Of Brain
You might see where this is going. The human brain grew in response to more cooked food, then that brain allowed humans to develop more ways to find and cook food again. It was a positive feedback loop that continuously supported further human evolution towards the creatures we are today.
It’s hard work being a farmer, but it can also bring some huge rewards. People switched to agriculture from their old hunter-gatherer ways partly because it was a more reliable way to ensure they could regularly eat nutritious meals. They wouldn’t have been able to do that without the energy needed to labor in the fields.
Energy is the key here: from the sun, harnessed naturally by plants and animals we consumed, and from the fire we used to cook our food. In these ways that same energy then ended up being passed onto humans who then used it to become more dominant. It drove not just increases in human intelligence, but also fueled a growing economy and society.
Cereal could be eaten immediately, or stored for the cold, dead winters when you couldn’t find food anywhere else. Once you’d seen to your own immediate needs, though, you could still have crops left over. Some would go into next year’s harvest. Others might be fed to your cows and horses to allow you to expand your farm even further.
After all of that, if you still had crops then you could trade them with other people for different foods or tools that you still needed. Again, you could enter a positive loop where as you grew more crops you could breed more animals and could secure more food, which in turn led to being able to expand and improve even more.
Bigger, better farms meant that the human population could continue to grow. It reached the point where not everyone was needed to work the land, which meant people could start turning their eyes to other pursuits: toolmaking and housebuilding to name just two. All this slowly led to the establishment of hierarchical societies with leaders and followers.
Longer Working Hours
And that’s where we get to the disadvantages of these larger and more civilized populations. Hunter-gatherer societies tend to have shorter working hours and longer periods of rest. When they do manage to find food then it’s shared equally among everyone. Settled agricultural communities saw a division for the first time between laborers and consumers.
Farmers might spend hours planting and harvesting, only to have their crops taken by warriors with swords and spears. Some people worked and others lived off of that work. It carried on like this until roughly the 18th century, and the Industrial Revolution, which was again driven by energy.
In particular it was fossil fuels that dramatically expanded the energy we could produce and in turn the food we could grow and tools we could make. Housebuilding rapidly increased to cope with a growing population. Horse power was replaced by steam, then internal combustion and eventually jet propulsion.
Easier Than Ever
Humans are now living longer and are generally much healthier than we ever have been before. In many parts of the world we have constant access to foods that our ancestors would have considered luxuries. Communication is easier than ever thanks to cell phones and computers, and we can even travel in person to the other side of the world in just hours.
A Long Way To Go
That doesn’t mean we’ve reached perfection. We’re reaching the limits of what we can do with fossil fuels without irreparably damaging our planet, plus they’re in limited supply. Rethinking energy yet again has made us look back to how we used to do things when we were powered by sunlight. But just think where we’d be now if we hadn’t started cooking our food…