An Over-Hasty Food Chain Jump

Climbing the Food Chain Too Quickly

Evolution usually takes a very long time. Genetic and epigenetic factors tend to be the driving forces behind evolution, and changes to the genome or expressions of genes are usually quite slow. Over thousands to millions of years certain traits in species change, certain genes end up with errors that turn out to be beneficial for survival, and species slowly evolve. In most ecosystems across Earth’s history, predators, prey, and everything living have co-evolved in a slow but steady manner.
However, evolution does seem to have its shocks. This can be seen in theories of punctuated equilibrium, where things are stable with small changes occurring at relatively constant frequencies punctuated by periods of rapid and dramatic changes. Perhaps a volcano erupted and changed the landscape of an ecosystem. The genetic changes that were previously advantageous might not be advantageous now, and perhaps a whole new set of genetic mutations become advantageous. Or perhaps an invasive species has moved into the ecosystem and is upending a balance that evolution and natural selection had settled upon, reshaping the ecosystem and what traits are the most beneficial for the survival of all creatures.
In his book Sapiens, Yuval Noah Harari describes the quick ascension of humans as a force toward punctuation in the history of evolution on planet Earth. We are similar to a volcano or invasive species in terms of our destructive and disruptive power. For over a million years humans evolved slowly, positioned in the middle of the food chain, but  relatively rapidly, we rose to the top of the food chain and became the most dominate animal on the planet.
Harari writes, “Other animals at the top of the pyramid, such as lions and sharks, evolved into that position very gradually, over millions of years. This enabled the ecosystem to develop checks and balances that prevented lions and sharks from wreaking too much havoc.” Most apex predators evolved over a long period of time alongside the same prey and other living creatures, allowing animals to find their niches and natural defenses to live in a type of balance within an ecosystem.
Harari continues, “humankind ascended to the top so quickly that the ecosystem was not given time to adjust. Moreover, humans themselves failed to adjust. … Many historical calamities, from deadly wars to ecological catastrophes, have resulted from this over-hasty jump.” When humans went from mid-food chain to the top in only a few thousand years, we created a punctuation in the evolutionary course of the planet. Tool use, advanced social tribes, and coordination and cooperation among humans allowed us to disrupt the slow and steady process of evolution that allows living creatures to steadily evolve together. Other species couldn’t adapt quick enough, and a mass extinction is the end result.
Further, Harari argues that our quick jump in the food chain didn’t allow humans to evolve and adapt – in terms of our psychology – to our new position. We possess fears and insecurities that are tied to our tribal ancestry. We live as if we are still in the middle of the food chain, and not  the top. Our quick ascent was so fast that we still haven’t caught up with exactly what the change means and where we are, and as a result we still live with the same fears that our ancestors had when they were in the middle of the food chain. This insecurity, Harari argues, has contributed to wars, deliberate decimation of other animal species, and various negative things that humans have done to each other and the planet since becoming the most dominant species.
Are Humans Really Hunters?

Are Humans Really Hunters?

One skill that I have is the ability to see the narrative in the way that people understand the world. I think there is some level of an objective reality in the world, but it is often hard to see and understand because we layer so many narratives together to define the reality around us. I think I do a pretty good job of seeing the narratives that people tell themselves and of understanding why people are attracted to certain narratives. One such narrative that I think deserves to be questioned is the idea that humankind are natural hunters, that we are apex animals, and as such, our men (in particular) should be dominant and should exercise their natural urge to hunt and kill.
This is a narrative that has lost a lot of appeal in the United States and other WEIRD – Western, Educated, Industrialized, Rich, Democratic – countries, but still has a lot of power. People who gravitate toward such a narrative tend to be described as more traditionally conservative than people who eschew such a label in cultures like ours. In other cultures across the globe, the narrative is still a lot stronger, and countries like China are cracking down against sissy men who seem to violate the narrative. But are humans natural hunters? Are we really such powerful apex predators with urges to hunt and kill? Yuval Noah Harari argues that this narrative doesn’t seem to fit the evidence and leading scientific thoughts on exactly where humans have fit within the food chain for most of our evolutionary past.
“Humans who lived a million years ago, despite their big brains and sharp stone tools, dwelt in constant fear of predators, rarely hunted large game, and subsisted mainly by gathering plants, scooping up insects, stalking small animals, and eating the carrion left behind by other more powerful carnivores,” writes Harari. What is important to note is that for humans, who date back about 2 million years, a majority of our evolutionary past was not spent at the top of the food chain. There was a very long evolutionary past where humans were vulnerable, and rarely did any hunting that we would like to associate with early humans if we hold the narrative of humans being natural hunters and the most powerful animal on the planet. Harari continues, “one of the most common uses of early stone tools was to crack open bones in order to get to the marrow.” For much of human evolution, we were more scavengers than hunters, waiting for more dangerous predators (lions, hyenas, and such) to clear a carcass before we came along with our smart brains, deft hands, and insightful tool use to access the bone marrow the animals couldn’t easily get to.
I think it reveals a lot to note that the narrative of man as tough, aggressive, hunter-killers is common, while the narrative of man as a ingenious scavenging coward is not a narrative that anyone adopts. It may be more accurate to say that we are clever and find ways to pick up the scraps that other animals left behind, but no one wants to view themselves or humans broadly as scavengers. No one considers it “natural” to eat road kill, yet many diets are based on eating “natural” caveman diets that are based around the idea of hunting and killing our food.
“Genus Homo‘s position in the food chain was, until quite recently, solidly in the middle. For millions of years, humans hunted smaller creatures and gathered what they could, all while being hunted by larger predators,” writes Harari. The idea that man needs to hunt, that men need to be aggressive and kill, and that our survival is dependent on how tough our men are, is largely a narrative. I realize I am leaving out inter-human conflict and combat, but at least in terms of what humans evolved to eat, it is more narrative than objective reality that we need to eat lots of meat and kill animals for our diets. Humans evolved as scavengers, and only recently jumped to the top of the food chain.
Early Births and Socialization

Early Births & Socialization

“Compared to other animals,” writes Yuval Noah Harari in his book Sapiens, “humans are born prematurely, when many of their vital systems are still under-developed.” Harari explains that humans are born so early because humans walk upright. As humans evolved, we began to stand and walk on two legs, rather than walk on four legs or primarily walk on two legs while greatly supporting ourselves with our arms. A consequence is that female hips narrowed to support an upright gait, which in turn restricted the birth canal, meaning that infants born sooner were more likely to survive because they were smaller and less of a risk to a female human with a relatively more narrow birth canal than other species.
In evolutionary terms, earlier births had additional consequences for the direction in which humans evolved. Harari continues, “since humans are born underdeveloped, they can be educated and socialized to a far greater extent than any other animal.” Raising a child is difficult work, and raising infants who are born under-developed and then develop slowly takes the work of many. Harari’s suggestion is that raising human infants was not possible for our female ancestors to do on their own – at least it was incredibly difficult compared to females raising their infants within a tribe. It would have been hard for a lone female to forage for sufficient food and to provide defense for herself and the infant. As a result, “evolution thus favored those capable of forming strong social ties,” writes Harari.
I find this explanation of the evolution of human social skills pretty convincing, even if I can imagine particular instances where it may not necessarily fit. I think it is reasonable to assume that there was a dual feedback mechanism, where evolving brains shaped our physiology, and where our evolved physiology in turn shaped our brains. As we got smarter and as evolution favored larger brains and increased cognitive capabilities, our bodies changed to adapt to our brain, and certain physiological traits were more advantageous to a species with increased cognitive abilities. Those physiological traits and characteristics, like narrow hips and birth canals, changed the size of the brain at birth, changing the cognitive capabilities of human infants. This allowed infants to be socialized at a younger age and favored individuals who were better at being part of a community, changing the dynamics for what type of cognitive abilities were favored by natural selection.
There was no clear evolutionary path and no way to predict where the future would go based on the past. Social factors, physiological factors, environmental factors, and other factors we have not identified all likely shaped the evolution of humans. We adapted to fit the circumstances and evolution favored different ways of being human at different times. I think this is a lesson we can still learn lessons from today. We can learn that we will evolve and that different ways of being human will be favored at different times based on many factors unique to our time, space, cultures, and environments.
Increasing Brain Power, But Little to Show

Increasing Brain Power With Little to Show

I recently listened to Gastropod’s episode about barrels, and the hosts said that we don’t know a whole lot about the development of barrels throughout human history. One reason why we don’t know too much about ancient barrels is that barrels are made of wood, which decays and disappears over thousands of years.  We can study pottery and containers for food and drink made of earthenware because it can be more easily preserved than wooden vessels. Barrels can only be studied tangentially, since original specimens are hard to come by after a thousand years of decomposition.
Gastropod’s episode about barrels represents a challenge faced in all ancient history studies and sciences. How do we learn about things that don’t leave permanent remnants behind? What is reasonable to conclude from the absence of physical artifacts? What inferences are reliable and reasonable, and what inferences are biased because we don’t have something physical that could tell a story?
Yuval Noah Harari ran into this problem in his book Sapiens. About the evolution of early human species and the development of big brains he wrote, “for more than 2 million years, human neural networks kept growing and growing, but apart from some flint knives and pointed sticks, humans had precious little to show for it.”
He explains that our brains allow us to make many marvelous things today, from laptops to skyscrapers, that give us a clear advantage over the rest of the world. Our brains use a lot of energy and our species evolved away from big muscles, claws, and teeth to support our big brains. This payoff doesn’t really seem worth it if it took more than 2 million years to get from no tools to where we are today. A few flint knives and pointed sticks, Harari argues, is hardly worth the costs of developing big brains which left us vulnerable to more threatening animals.
A problem I think that Harari runs into is that we can’t look back at 2 million years of human evolutionary history and see the things that nature wasn’t able to preserve for us. For all those years of evolution we may have only been developing rudimentary physical tools, but we may have been developing new tools that we can’t look back and see, mainly mental tools and institutions.
This is an argument Robin Hanson and Kevin Simler might make. In their book The Elephant in the Brain, they argue that social interactions, in particular complex political interactions between humans, drove the evolution of our brains. Increasing our brains so that we could better work together and develop political groups would not leave a trace we could identify through physical artifacts like stone tools.
Additionally, early evolving humans with their increasing brains may have been developing more physical items than we give them credit for. Because many of the things they created may have disappeared due to natural decomposition, we might not have a record of them. I am sure this is something that people in the field know much better than me, and I’m sure something that Harari is aware of as well, but it is not well presented in Sapiens. His argument that the evolution of the brain did not have immediate payoff in terms of physical tools that would help the species survive is still valid, but it is narrow and leaves out other important advantages that the evolution of big brains brought to humans.
Why Giant Brains Are So Rare

Giant Brains Are Rare

In Sapiens, Yuval Noah Harari explains that Homo sapiens means wise man. It is a term we have given ourselves as a species because we have large brains and use those large brains to set ourselves apart from the rest of the animals and creatures on the planet. There are some other species with big brains, but in general large brains are rare, and no other species has been shown to use their brain to the same competitive advantage as humans.
But if large brains have made us so competitive across the globe, why are they so rare? Harari writes, “The fact is that a jumbo brain is a jumbo drain on the body. … in Homo sapiens, the brain accounts for about 2-3 percent of total body weight, but it consumes 25 per cent of the body’s energy when the body is at rest. By comparison, the brains of other apes require only 8 per cent of rest-time energy.”
Our brains are incredibly active and use a lot of sugars for fuel, even when we are not doing anything. This is great news for those of us who are trying to go on a diet to lose some weight today, but it was not great news for our ancestor hunter-gatherer humans and proto-Homo sapiens species of the past. According to Harari, large brains essentially have a high up-front cost. There is a large energy up front energy cost that goes into maintaining the brain before a species can really use the brain to a competitive advantage, and that has been a barrier to other species developing large brains and using them in a way that could give them a competitive advantage.
Harari continues, “Archaic humans paid for their large brains in two ways. Firstly, they spent more time in search of food. Secondly, their muscles atrophied. … A chimpanzee can’t win an argument with a Homo  sapiens, but the ape can rip the man apart.” Strong thinking and reasoning skills are helpful today and are the reasons we live in houses, build rocket ships, and are able to develop vaccines to end global pandemics. However, our big brains are not always the best tool to bring to a fist fight. It is not obvious that better reasoning skills will help a species survive better than sharp claws and teeth, thick hides, or spiky spines. Evolution doesn’t have an end goal in mind, and for all species besides the human species that evolved into Homo sapiens, the big brain payoff simply wasn’t the evolutionary rout that provided the best chance of survival and spread. It wasn’t until the big brained human species began to live and interact in clusters and tribes, communicating and working together, that big brains and reasoning skills could begin to pay off and become competitive against larger animals with bigger muscles and more ferocious claws, teeth, and tusks.
Three Major Revolutions

Three Major Revolutions

Yuval Noah Harari explains the evolution of humankind through three major revolutions in his book Sapiens. Harari takes a long view of humanity, trying to understand our very origins as a species and how we became who we are today. The three revolutions he identifies changed the course and direction of the evolution of humankind, and might lead to us becoming something unrecognizable in the future.
Harari writes, “the Cognitive Revolution kick-started history about 70,000 years ago. The Agricultural Revolution sped it up about 12,000 years ago. The Scientific Revolution, which got under way only 500 years ago, may well end history and start something completely different.”
This quick quote shows that the development of humans has been long and slow, but that recent changes have been dramatically quick in comparison. Human brains began to change dramatically during the Cognitive Revolution, but those changes did not spark instant societies and further tool use or manipulation of nature. 50,000 years of evolution took place before an Agricultural Revolution, which marked another change in human behavior, thinking, social structures, and life. What it meant to be human and the experience of living humans changed little in the 50,000 years between the Cognitive and Agricultural Revolutions, even though our minds were evolving dramatically.
But in the last 500 years, with the Scientific Revolution, the human experience has changed dramatically. It is possible that these dramatic changes and advances will continue, to the point where humans will no longer be recognizable as human when compared to the species that kicked off the Cognitive Revolution or the Agricultural Revolution. The Scientific Revolution put us on a new path that may end up with humans fusing with computers and machines to be human in a way, but not in a way that a human from 12,000 years would recognize.
Co-opting Mental Machinery

Co-opting Mental Machinery

The human mind is great at pattern recognition, but it is not the only brain that can recognize a pattern. Pigeons can recognize patterns for food distribution with button presses, mice can remember mazes and navigate through complex patterns to a reward, and other animals can recognize patterns in hunting, mating, and other activities. What humans do differently is use pattern recognition to determine causal structures by imagining and testing alternative hypotheses. This is a crucial step beyond the pattern recognition of other animals.
In The Book of Why Judea Pearl writes, “It is not too much of a stretch to think that 40,000 years ago, humans co-opted the machinery in their brain that already existed for pattern recognition and started to use it for causal reasoning.” This idea is interesting because it explains our pattern recognition linkage with other animals and helps us think about how brain structures and ways of thinking may have evolved.
In isolation, a brain process is interesting, but not as interesting as when considered alongside similar brain processes. When we look at pattern recognition and its similarities to causal reasoning, we see a jumping off point. We can see how brain processes that helped us in one area opened up new possibilities through development. This helps us think more deeply about the mental abilities that we have.
The ways we think and how our brains work is not static. Different cultural factors, environmental factors, and existing brain processes can all shape how our brains work and evolve individually and as a species.  As Pearl notes, it is likely that many of our brain processes co-opted other mental machinery for new purposes. Very few of what see in human psychology can be well understood in isolation. Asking why and how evolution could have played a role is crucial to understanding who we are now and how we got to this point. Causality is not something that just existed naturally in the brain. It was built by taking other processes and co-opting them for new purposes, and those new purposes have allowed us to do magnificent things like build rockets, play football, and develop clean water systems.
Thinking Fast and Evolution

Thinking Fast and Evolution

I have written in the past about how I think I probably put too much emphasis on evolutionary biology, especially considering brains, going all the way back to when our human ancestors liven in small tribes as hunter-gatherers. Perhaps it is because I look for it more than others, but I feel as though characteristics and traits that served us well during that time, still influence much of how we behave and respond to the world today. Sometimes the effects are insignificant, but sometimes I believe they do matter, and sometimes I believe they drive negative outcomes or behaviors that are maladapted to today’s world.


As I have begun writing about Daniel Kahneman’s research as presented in his book Thinking Fast and Slow, I have generally given System 1, or what Kahneman describes as our quick, automatic, and reactive part of our brain, a bad rep. But the reality is that it serves an important purpose, and likely served an especially important role over the course of human evolution, getting us to the place we are at today. Knowing that I tend to weigh our evolutionary past heavily (and perhaps too heavily), it is not surprising to me that I view System 1 as an important piece of how we got to where we are, even if System 1 is easy to pick on in our current world.


In his book, Kahneman writes, “Any task that requires you to keep several ideas in mind at the same time has the same hurried character. Unless you have the good fortune of a capacious working memory, you may be forced to work uncomfortably hard. The most effortful forms of slow thinking are those that require you to think fast.”


Anyone who has had to remember a couple of phone numbers without the benefit of being able to write them down or save them immediately, and anyone who has had to remember more words than Person, Woman, Man, Camera, TV, knows that we feel super rushed when we are suddenly given something important to hold in our working memory. We try to do what we can as quickly as possible to get the information out of our head, stored someplace other than our working memory. We feel rushed to complete the task to ease our cognitive load. Why would our brains work this way? Why would it be that we become so rushed when we have something meaningful that we need to hold in our mind?


The answer, as I view it, might go back to our hunter-gatherer ancestors. They mostly needed System 1. They had to react quickly to a noise that could be a dangerous predator. They had to move fast and on instinct to successfully take down dinner. There were not as many things that required deep focus, and the things that required deep focus were not dense academic journal articles, or spreadsheets, or PowerPoints, or a guy with a clip-board asking you to count backward from 200 by 13. You don’t have to worry about pop-ups or advertisements when you are skinning an animal, grinding seeds, or doing some type of work with your hands in a non-digital world. You didn’t have phone numbers to remember and you were not heading into a business meeting with four people you just met, whose names you needed to memorize as quick and fluidly as possible.


Slow thinking developed for people who had time for slow thinking. Fast thinking developed when survival was on the line. Today, the slow thinking might be more likely to help us survive than our fast thinking, presuming we don’t have dangerous drives to work each day and are eating safely prepared foods. Slow thinking is a greater advantage for us today, but we also live in a world where slow thinking is still difficult because we have packed more distractions into our environments. We have literally moved ourselves out of environments for which our brains are optimized by evolution, and this has created the challenges and conflicts we face with System 1 and System 2 in our daily lives and in the work we do.
Puzzling Over Wealth

Puzzling Over Wealth

We like to show off. We like to have nice things to impress other people, and we like when people notice our things, compliment us on our fancy stuff, and respect us because of the wealth that we have. It is an instinct that likely evolved as humans lived in small tribes. If you had an ability to accumulate resources, you could be seen as a valuable ally, and you became a more attractive mate. Those who were good at creating allies and demonstrating their value through resource dominance passed their genes along.


The problem is that we don’t have an easy off switch for our resource signaling behavior. Finding a partner, having children, and living comfortably might not always be easy, but the way we compete for these things is different in the 21st century than it was eons ago when our early ancestors were living in small nomadic tribes. Today many people have sufficient wealth to live comfortably and are able to get married and have children or even adopt without the need for overt displays of wealth. Nevertheless, all around us is the pressure to have more. We are tempted to spend more on housing, buy new cars,  take more impressive vacations, and signal our wealth through our material possessions. Without a real reason, we still push ourselves in a signaling game to show off our wealth, and as we do, our possessions and wealth steal the meaning and enjoyment from our lives.


In Letters From a Stoic, Seneca wrote, “While he puzzles over increasing his wealth, he forgets how to use it. He collects his accounts, he wears out the pavement in the forum, he turns over his ledger—in short, he ceases to be master and becomes a steward.”


The pursuit of wealth for purposes of showing off and signaling leads us to have things we can’t enjoy. We become so fearful of losing our stuff that we lose connections with our communities and fellow citizens. We become willing to subject ourselves to longer work hours, worse working conditions, and lengthy commutes so that we can have nice things. We trade off the qualities of life that make it meaningful and enjoyable so that we can show off to others. In the process we become servants to our wealth, and rather than using the resources we acquire for a positive impact on the planet, we allow our wealth to have negative impacts on the planet and on our very own lives. We should puzzle over our wealth to ask ourselves what is needed for comfort, security, and to have a bigger positive impact on our communities and planet, rather than puzzle over our wealth in pursuit of more for ourselves.

A Feeling of Importance

“If our ancestors hadn’t had this flaming urge for a feeling of importance, civilization would have been impossible. Without it, we should have been just about like animals,” writes Dale Carnegie in his book How to Win Friends and Influence People. Carnegie is hitting on an interesting idea: how the desire to be important has fueled human evolution and impacted the species we are today.


This is an idea I wrote about in the context of both competition and coordination for our early ancestors. In The Elephant in the Brain, Kevin Simler and Robin Hanson write about the ways that insecurity and limited resources drove the human brain to be deceptive and political, finding ways to cheat to obtain resources without letting on to other members of our social tribe that we were not 100% honest. Conversely, the authors write about how as a result of this cheating and politically deceptive behavior, our brains became bigger and we became more intelligent, opening up the possibility of future planning and productive social cooperation.


Underlying both our cooperation and competition instincts is social status. For our earliest ancestors social status meant that you could obtain a mate, and as we evolved higher social status meant that you could also command more resources and have more allies and protection within your social group. For our early ancestors, having a high social status (in the eyes of Carnegie being important) meant that your genes would continue and that you had allies and resources to make it more likely that your genes were passed on to the next generation and the following generation.


Today, we still maintain that need to feel important and to build our social status, even though for most of us we can pretty well guarantee the continuation of our genes with limited resources and minimal social status. Our feeling of importance remains, but its original drivers have been nullified (at least in a large way in rich countries like the United States).


Carnegie continues in his book to write about the sense of ego that accompanies and drives our desire for importance. It can push us to do great things, but can also have extreme negative consequences for us as individuals and for society in general. Our ego, tied to our desire for importance (or increasing social status as Hanson and Simler would say) is important for us to understand and control. At a certain point we need to acknowledge that we do things just to make ourselves seem more important, and that things that can be good for our social status can be harmful for others. We should reflect on the decisions we make in this regard, and try to make decisions that at least reduce the external harm we cause. Giving up a small measure of our own social status in exchange for having a better world to live in is the least we can do given that we are operating on evolutionary drivers that no longer match our realities.