Shrinking brains and exponential changes 🧠🔥👩💻
How are you all doing? Personally, things are looking up here in Thailand. Roads are full of the climate-killing traffic again. Restaurants are back. There’s life on the streets and BTS is slowly getting filled up. I hear they are opening the malls today.
All of this makes me happy. We all suckers for the ‘normalcy’ of civilization we’ve created, even if we like to complain about the crowds, the traffic and the futility of capitalist consumption.
Speaking of civilizations, today’s newsletter is a little different. We step a little back in time, a few hundred thousand, to the birth of our ancestors.
Most successful species?🐒
Around 300,000 years ago, there are around nine different human-like species. It was about then that the first homo sapiens begin to evolve. Fast forward to 80,000 years back - the modern humans begin migrating out of Africa. Around 50,000 years back, we start developing the capacity for basic language. Zip through time again, to around 10,000 years ago and we began farming, irrevocably altering the course of our species and the planet.
Hundred centuries back, all the other humanoid species had been eradicated from Earth. Along with them, our ancestors had killed-off thousands of other species including ice-age mammals, and other large animals and many other species of fauna. Millions of acres of flora too became extinct across the face of the Earth.
The asteroid hit that killed the dinosaurs was a mass-extinction event in Earth but it probably pales in comparison to the other one that happened over several thousand years: The rise of homo sapiens.
The result: We have more people alive today - 7.8 billion or so - than we’ve ever had alive at any point in the history of our planet.
There’s no doubt we succeeded as a species because we ruthlessly self-preserve, overseeing genocides of entire species, taking opportunities or eradicating any source of threat on our way to the top of the chain. We combined this with stories. Inspiring heroic tales about us conquering adversity.
We’re so ruthless that we fear each other more than anything else. Global defense budget for 2019: $2 trillion.
Being ruthless is one but survival of the fittest also required us to spike on a trait that life prioritized given the circumstances of the planet: The size of our brains.
Big brains
In simple terms, Homo Sapiens became successful because of the literal size of our brains.
One could say our bodies are mere vessels to carry our brains today: While only 2% of the weight of our body, it consumes 20% of the energy.
From about 6 million years ago, when the first humans began to walk upright, until up to 2 million years ago, the size of the humanoid brain evolved extremely slowly to around 500 cubic centimeters in volume. More than a million years after that (until about 800,000 years ago), the size was around ~1000 cubic centimeters. The real acceleration came after that, in the span of just 600,000 years, the brain size grew rapidly to around ~1500 cubic centimeters.
The larger, more complex brains of the homo sapiens enabled them to survive and thrive. They made tools, interacted with each other to protect and hunt in groups, created specialized equipment and then moved on to producing our own food (farming, etc.) instead of hunting them.
After that, with a source of energy secured for our big brains (reliable supply of food), our species began to proliferate dramatically.
But why did the brains evolve in size so dramatically in such a short period of time?.
Pleistocene and climate change❄☀
Earth is a story of constant climate change. The historical periods are divided into epochs. Pliocene lasted from 5.3 to 2.6 million years ago. After that came Pleistocene which lasted from 2.6 million years ago to about 11,000 years ago. Since, we’ve been in the Holocene epoch.
The vast majority of the humanoid species evolved or demised in the Pleistocene epoch. This is also the era where the brains of homo sapiens grew drastically as I had outlined above. Why?
Pleistocene epoch was characterized by drastic climate changes, with multiple glacial and inter-glacial periods. We had the big Ice Age (which didn’t involve penguin dance numbers) where at one point glaciers (that you see in Arctic / Antartic) covered nearly 30% of the planet.
We evolved through these odds. We constantly wandered the planet as things became difficult. We adapted to varying temperatures - wet, dry and cold spells that altered drastically. The scarcity of food in colder climes made us hunt (and find tools to do so in the process) and preserve meat, to work in groups and share the burden. This resulted in natural selection towards homo sapiens with larger brains to think our way out of problems.
Then we moved into the Holocene epoch and really began to thrive. In general, Holocene is this nice, cozy epoch for humans (or has been till date). The planet is the right amount of warm, there hasn’t been drastic changes in climate. Humans started farming, destroying large portions of forests, started settling down and as a consequence began to proliferate rapidly across the planet.
And our brains have begun shrinking.
Our shrinking brain ☹
I am not trying to be facetious but our brains have started literally shrinking again. After about 2 million years of expanding brain capacity that took us from being savage hunters to civilization builders, our brains have started shrinking once again in the Holocene epoch. Over the last 20,000 years, we have lost about 150 cubic centimeters in brain size. That’s for both males and females, mind you, despite the fact that it may have been easier to believe that it’s been only happening for males (given the historical evidence of actions).
So, as a species we are rapidly paring back on our brain size that we gained so dramatically.
There are many explanations but they are all interconnected and may mostly have to do (directly or indirectly) with the same geological phenomenon that enabled the growth of brain size in the first place - Climate change. Or the lack of significant change.
Brains are high energy and evolution hates wasting energy - its goal is only extending the survival of the species to enable creating further progeny.
One explanation goes, as climate became warm and favorable, we didn’t need bulky bodies to preserve heat. Or, it’s possible that the grain-heavy nutrition brought forth by our farming revolution was actually poorer in nutrition, lacking in proteins and vitamins that are important for brain growth. Even paleontologists and cognitive scientists are not sure.
Or, maybe, just maybe, we are all becoming idiots.
Are we becoming idiots?🤪
Don’t laugh, but it may be possible that we are all becoming idiots even as we’ve invented more efficient and smart ways to run our lives. Think about it. We’ve been slowly inventing language to communicate, we’ve invented ability to capture knowledge to be passed on generations, and we’ve evolved into denser societies which do not require us to do much because over thousands of years, we’ve built and enabled systems that help us.
Complex societies make dumber humans?
Imagine any given human being being born to a tribe of 5 people in the Savannah. Think amount the sheer amount of learning curve and resourcefulness that the person has to posses to merely survive. Now imagine a kid being born in a nice apartment in a big city and think about how much stuff the person doesn’t need to figure out to survive.
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One could say that for a modern human there are two brains enabling him / her to survive and thrive in the world. The brain of himself / herself. And second is the accumulating brain of human knowledge and learning. As the second one keeps increasing, is our individual brains may be shrinking.
Add on top of that technology and you’ve now got the collective brain that is driven by computing power that’s moving at an exponential phase. While we are going down linearly?
Extended brain and exponential impact📈
By now, all of us have seen enough exponential graphs thanks to Covid. If nothing, I hope Covid taught a bunch of us the power of exponential changes. And that it may seem like things are fine for a long time only for it to drastically shift in a short period of time.
A more simple, common-sense explanation:
Many, and Ray Kurzweil is a chief proponent of this, posit that technological changes are similarly exponential. And that we may be in that part of the curve where the hockey stick begins to rise steeply. In fact, it may be more relevant to say that information evolves exponentially. And this is true ever since the first DNA formed.
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While the tools or wheel continued to remain as the technology in use for tens of thousands of years, imagine the shift in just the last 1000 years. Electric light, automobile, telephone, etc. Just not even a drop in the time humans have lived on this planet. Then imagine the last 100 years. Computing. Internet. Television. And then, in perhaps just about the last two decades, we have complete services built off the internet, e-commerce, cloud computing, smart phones, etc.
Kurzweil projects that we will have 200 centuries worth of progress (historically) in the 21st century (we had about 25 years worth of progress in the 20th century).
But, humans think linearly. It’s almost as if a group of monkeys discover fire in the morning, wheel in the afternoon, tools early evening, electricity an hour later and then in the few minutes before bedtime find everything from nuclear power to the internet. Yet, they are still monkeys.
The side effect of exponential change is we cannot think of exponential impact. The biggest exponential impact we refuse to respond to is climate change.
We owe it to our ancestors
Dr. Thomas Lovejoy of the Smithsonian Institution said in a speech: “A lack of appreciation for what exponential increase really means leads society to be disastrously sluggish in acting on critical issues…...I am utterly convinced that most of the great environmental struggles will be either won or lost in the 1990s, and that by the next century it will be too late.”
Even if we stop all emissions today, the warming will continue to go up. And we are nowhere close to stopping emissions today. Over the next few decades, we are going to see rising sea levels, water scarcity, crop yields impacted by drastic weather and significant species extinction due to loss of biodiversity (drying, fires, etc.).
Yet, we’ve held on to old ideological stories, unable to break free. We’ve clung on to the political, economic and national systems that served us well in the last century or so even while it was going irrelevant.
Did Covid help us learn about exponential impact? Did it help with a global experiment (for lack of a better word) into changing behaviors? I am not sure but hope we change some things for the better coming out of it.
The story of homo sapiens is one of evolving perhaps because of the odds. Our shared history of fighting the elements, putting our large brains to use, inventing our way out of problems has led us to this point. At a bare minimum, we owe it to ‘these’ ancestors (even more so than the ancestors they tell you to revere) to invent our way of our current problems using our brains.
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Could be worse,
Tyag