Our brains were shaped after natural selection. Which means that, as long as we were being affected by it, our brains were changing, evolving.

Once we stepped out of nature and stopped being targets of natural selection, our brains (structurally speaking) stopped changing.

Civilizations rose, humanities and science developed, and you know the rest of the story.

But the brains that we used to create all that is the same brain that was shaped by natural selection. A brain that was concerned with animal hunting, food gathering, fighting with enemies, relating socially and so forth. It is curious to notice that we used that same brain to develop algebra, geometry, physics, astronomy, arts, and so on.

So, would it be correct to say that all those activities from our ancestors living in nature (gathering, hunting, fighting) are INTELLECTUALLY equivalent to quantum physics, i.e.? Because our brain capacity is limited to what happened to it during natural selection (while we were living in nature), so would it be safe to assume that whatever complex thing we can think of (such as quantum physics) is actually as hard as those activities our ancestors performed in nature?

This may be a very stupid question, but I couldn't find fallacies or wrong assumptions in my thought, but my conclusion seems to be a bit... unexpected? Please, correct me if I'm wrong, I'd really like to know the answer to this.

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    $\begingroup$ "Human brains enjoy ongoing evolution" $\endgroup$ Commented Nov 21, 2016 at 5:11
  • $\begingroup$ 1. I have no proper-understanding of quantum-physics; as well, many passionate-people worked on evolution and nature, would say too, they don't know it well. So I'll suggest/ request you to add a small and simple excerpt about why you suspect that process like hunting and gathering is equivalent to quantum physics. As well; 2. we (and our brain) is made of atoms and molecules. So, if atoms and molecules obey quantum mechanics then why our brain will not do? 3. What you mean by 'intellectually equivalent'? did you mean 'conceptually equivalent'? $\endgroup$
    – user25568
    Commented Nov 21, 2016 at 13:13
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    $\begingroup$ "Once we stepped out of nature and stopped being targets of natural selection, our brains (structurally speaking) stopped changing." Why do so many people think evolution is "done" and that we're the perfect organism that cannot be improved upon? $\endgroup$ Commented Nov 21, 2016 at 13:25
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    $\begingroup$ Every time a couple reproduces, evolution continues. $\endgroup$
    – SethWhite
    Commented Nov 21, 2016 at 15:10
  • $\begingroup$ On what basis or scale do you intend to compare survivalist strategies and quantum mechanics quantitatively? As a side note, I am reminded of a book I once read about the early expeditions to map the Amazon. Despite having the tools of 19th century science, the explorers quickly changed their attitudes about the "savages" when they realized that the natives' intelligence and knowledge of the jungle far outstripped their own. I think your answer might be more along the lines of "complex tasks are complicated until you know how to do them". It's just hard to compare the two ideas meaningfully. $\endgroup$
    – syntonicC
    Commented Nov 21, 2016 at 17:21

6 Answers 6


Addressing some assumptions/presumptions apparently present in the question (this might be too long for a comment):

First, natural selection has not stopped. The sexual selection might be more active than ever, so there is ongoing "pro-fertility" selection and some segregation "pro-smarts". Not every member of contemporary potplation is capable, even with unlimited attempts at education, of doing something useful with quantum physics.

Second, surviving in the wild and fighting enemies are competitive enterprises. Which means that the task is of potentially unlimited difficulty: the better you are at survival, the more you procreate, the more pressure you put on limited resources of the environment, to harsher climates you spread. With enemies, especially those evolving along with yourself, this unlimited competitiveness is even more obvious.

So, the question could possibly be framed differently: how hard our ancestors, living in nature, made the intellectual part of the task of competing with each other? Apparently, about that hard.

  • $\begingroup$ Re the competitiveness and therefore unlimited difficulty: it’s theoretically conceivable for there to be an upper limit imposed by physical constraints. For instance, trees have an evolutionary arms race for height in forests, yet there are various physical limits on how high trees can evolve to grow. For brains, a conceivable limit may be due to the considerable amount of energy we need to expend for our smarts (this is pure speculation of course, but it’s plausible). $\endgroup$ Commented Nov 21, 2016 at 19:14

You seem to think that living in the natural environment is "easy". But, even when the climate helps, even when you have no war to fight or defend against, even so you have to know the habits of the animals which you will hunt, the fishes you fish, the proper season of the plants (fruits, fibers, roots...), which of them could be toxic, which could be medicine; when planting you have to know the season for planting, the season for harvesting, not to mention which plants grow well near which others, and which grow sick close to which others, what are the proper soils and proper irrigation for each species, how to deal with pests, etc.

As you can see, if you try to do those things, you will probably acknowledge that they're not necessarily easier than modern science. After all, nobody created the whole of "quantum physics" out of thin air. There were many different discoveries developed by independent researchers over a long time, with many trial and error in between, etc. And all this, of course, was only made possible after the extreme specialization that - in the end - probably turned us "modern civilized people" into the least healthy and more emotionally tormented version of our species.

So yes, to be human is enough challenge for anyone. To be a single mother is probably more difficult than any dry and tedious mathematical equations.

  • $\begingroup$ It may not be easy but it can obviously be done without any symbolic reasoning at all, for example by a worm or a fly. And even with symbolic reasoning one could argue that memorizing plants is not the same as contemplating curved space time or Riemann's conjecture. What you say may be right; but the argument is not rigorous. $\endgroup$ Commented Nov 21, 2016 at 10:27
  • $\begingroup$ @PeterA.Schneider Worms and flies only eat what their instincts have prepared them for. Even ants that tend aphids are not able to learn what "genetical enhancement" might be. Our brains have the biggest ability to learn, and we did this to domesticate dogs, horses, plants... The first man who thought he could mount a wild horse and fall, and mount again and fall again, until he finally tamed it, has surely had some "symbolic reasoning", didn't he? My point is, if we have room for symbols, this must have arised in the old past of our species. $\endgroup$
    – Rodrigo
    Commented Nov 21, 2016 at 17:55

I don't think this is really a biology question; philosophy, maybe. Or for the history and philosophy of science.

The main problem is: what does "INTELLECTUALLY equivalent to" actually mean? What sort of equivalence is it? There isn't a convenient Mohs scale we can use to measure the hardness of problems.

We don't actually have a good biological model of what it means to think about something. We know it involves neuron activation, and you've probably seen the use of fMRI to map exposure to various thoughts to rough activation patterns in the brain, but it's not a model we can replicate yet nor describe in truly precise detail.

We don't have a clear enough description of what it means to think about something to say which animals think and which don't. We know that crows understand object permanence. Some chimps can understand symbolic reasoning. Does that imply some equivalence with human cognition?

"stepped out of nature and stopped being targets of natural selection" is also an assumption which I'd like to question. When do you think this happened? The earliest I think you could possibly justify would be the invention of antibiotics in the 20th century.

It's possible that something like Turing equivalence applies to thought; once a particular level of symbolic reasoning is reached, from there the entirety of mathematics is reachable given enough time and effort.

  • $\begingroup$ "stopped being targets of natural selection" happens gradually, of course, and is not finished (one can still die from cancer before procreating). But physical resilience was less and less needed with the growing degree to which we shape our environment (build shelter, heating, grow food) and help each other (support the weak, heal the ill, technically fix issues like myopia). $\endgroup$ Commented Nov 21, 2016 at 10:54

I won't address all the assumptions/propositions you offer in your answer, just the basic question:

would it be correct to say that all those activities from our ancestors living in nature (gathering, hunting, fighting) are INTELLECTUALLY equivalent to quantum physics, i.e.?


What do you need to live in prehistoric times?

  • Observe your environment
  • Understand what is happening (beyond basic animal instincts)
  • Form plans of how to survive better
  • Enact those plans (possibly as a community)

What do you need to do quantum physics?

  • Observe your environment (=read books, go to university)
  • Understand what is happening (=understand the mathematical formulas etc.)
  • Form plans of how to make it better (=have intiuitions about where to go for new developments in QT)
  • Enact those plans (=actually work out full-fledged new theories and successfully run them past the QT community)

(You can think of more points, for example "storing/accessing knowledge" and probably more).

Analogy: computers

There is an excellent analogy with computers. Since we developed the "Von Neumann architecture" for computers, computers basically did not develop much further. Yes, there were vast, unbelievable improvements in capacity and speed, but that's about it. Fundamentally, every computer you have today, including laptops, smartphones etc., are conceptionally exactly the same as the first computers around the middle of the 20'th century.

The achievement was to build a general computing device that can be applied to any problem whatsoever, without even knowing what the problem is. Once you are at that point, you're basically "done".

The same goes for the brain: once you reach the point where you have all the basics (understanding, reasoning, communication etc.), you're all set. You "only" have to increase capacity/speed to achieve almost anything. Obviously we cannot really scale capacity/speed of a single human brain; I would say we achieve this today by making fields like physics, mathematics, electronics etc. ever more compartmentalized. The time where a single human could know everything humanity has learned about a topic is long, long gone. But basically, it is the same.

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    $\begingroup$ Could you provide some references? $\endgroup$
    – Ebbinghaus
    Commented Nov 21, 2016 at 12:51
  • $\begingroup$ @Ebbinghaus, for which part of the answer do you need references? I believe it's pretty self-explanatory and general enough to not need any? The "Von Neumann architecture" is the only term requiring explanation, but it is quite ubiquitous, and any Google hit for it will suffice. $\endgroup$
    – AnoE
    Commented Nov 29, 2016 at 14:39

Unlike the other answers, I'd like to focus on the issue of intellectual performance. If you're trying to ask whether the hunters and gatherers used to use their brain capacities as much as we do, assuming we haven't evolved much since then, the answer is yes. Though, it hadn't been the same type of brain performance. Most of the knowledge needed for hunting is procedural (implicit) information, something you can learn by watching and repeating your parents' techniques. In nature you have to be careful not miss any predator's noise and you have to be always prepared to run. This characteristics fits the brain condition today known as adhd. And, indeed, this hypothesis of the origin of ADHD as an regiment from the times of hunter-gatherers is currently being confirmed by the genetic research.

So if I got you right, I think your hypothesis is right, we use our brain capacity as much as the hunter-gatherers did. But, as can be seen on adhd, non-adhd people are better equipped for the conditions of the today's world (therefore it's called a deficit, they usually score worst in IQ tests) but people with ADHD might have better chance of survival in the wild (because they use more of their brain capacity focusing on potential danger).


I think you are underestimating the intellectual capacity needed by prehistoric humans to perform all their activities; in short, to survive. It is true, prehistoric humans did the same things animals did. But they did it in a fundamentally different fashion.

Animals are largely driven by instinct. By contrast, we humans have very few instincts — perhaps none! — we cannot overcome. We can choose not to follow even the most basic survival instincts: We can voluntarily hunger to death, refuse to procreate, go out in the cold and freeze to death, with a warm home in sight. We can even actively end our lives.

But this freedom from pre-cast behavior has enormous benefits: It enables us to adapt to environments to which we are physically not well suited. Too light-colored people inhabit the Sahara; fur-less humans dwell in the arctic. We grow food in arid places, by means of irrigation. What makes this possible is a system of knowledge and customs commonly referred to as culture. This puts humans in a unique position among animals. Our survival depends on our mental capacity, not any longer on our instincts or our physical shape.2 This shift is what characterizes us. This shift was made possible by a change in our brains.

Some time in the evolution of homo sapiens something astonishing happened. It is the ability for symbolic reasoning and reflection. We see things not only as what they are; we imbue meaning in them which isn't obvious at face value. We tell stories about ourselves, about our ancestors, and about everything else we see. We keep memories of the past, and tell them to our children. We have rites which reinforce these memories and our sense of belonging, belonging to the place and to each other. The stories we told (like heavens full of scheming gods) were often much more complicated than the reality they tried to explain (like rotating balls on elliptic trajectories). We could create an adaptive symbolic working model of ourselves and our environment; one which was elaborate and complicated, and often poetic and beautiful.3

This ability proved an evolutionary advantage in times of rapid environmental changes and allowed us to survive where other species went extinct. We developed a brain that's "almost entirely plastic" (Feynman)1.

This unique ability to create internal models of the ever-changing world around us allowed us to make Gedanken-Experimente, predict the consequences of our actions. We could be strategic. Ockham hadn't been around yet, and the Ptolemaic way of making sense of it all was blossoming.

This ability to create and manipulate mental models with a high degree of freedom (not hard-wired to specific inputs or instincts) is key to our humanity. The result of our evolution was a brain which is almost completely unshackled. It is aggressively designed to invent stories and see patterns. We are the zoon politikon as much as we are a zoon poetikon, a story teller and singer.

Our mind is not modeled for a specific environment. We can live everywhere we can physically go — and beyond! This enables us to do things that seem very removed from what we did when we evolved. We are physical explorers as much as we are mental explorers. The very advantage of this particular line of evolution, its very essence is that it is not only ready for the unknown, but actively seeking it.

Stay tuned.

1 The lady whose leg he pulled responded: "No, really!?"

2 In fact, our instincts, for example our aggression, appear to become a danger to our survival rather than a requirement.

3 As an example for sophistication and information content consider Australian Aboriginal mythology with stories possibly describing events thousands of years ago.


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