As a result of several thousand years of evolution, man has received an unusually developed (in comparison with other, even the most intelligent animals) intelligence. But what made us so unique?
What evolutionary path have we taken? Of course, we will hardly be able to get an unambiguous answer to these questions, but we may well make some assumptions, even if they sound rather strange.
1. A mutation that spread from a single ancient man
Evolutionary change can happen in two ways:
The first is microevolution, that is, small, gradual changes over a long time.
The second is macroevolution, that is, a sharp leap in the development of an organism.
There are several theories about the interaction of these two processes, one of which is known as "macromutation" - a genetic disorder, as a result of which one individual turns out to be completely "special", not like its relatives. In fact, this is already a new biological species (remember at least the mutants from "X-Men").
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Colin Blackmore, a neuroscientist at Oxford University, believes the same thing happened to humans. Some of our ancestors were born with a severe genetic defect that made him or her a little smarter than the rest of the ancient people. It was an absolute coincidence, which turned out to be quite useful in terms of survival, and this person passed on this "defect" of his own.
2. DNA feature
During a project to decipher the human genome, researchers discovered something completely unique in our DNA: a duplicated SRGAP2 gene, which is known to be responsible for brain development.
No other primate (and indeed no animal, for that matter) has anything like this. That is, most likely, at some point in human history, there was a "glitch".
In fact, we have several copies of SRGAP2, which are basically "genetic junk" and are called SRGAP2B and SRGAP2D.
But SRGAP2C is a truly fully functional copy of SRGAP2, which can actually replace the original gene.
When SRGAP2C was implanted in mice, the original gene was turned off. If you think of this system as software, then SRGAP2C will be an evolution of the 2.0 brain, which must remove version 1.0 to work correctly.
3. Brain development is associated with upright posture
One of the unique features of humans is the soft fontanelles on babies' skulls. These areas not protected by bones make it easier for the newborn to pass the birth canal and harden only by two years.
Other primates do not need such features - simply because they are not bipedal, and their birth canal is much wider.
Studying the well-preserved skull of the child Australopithecus, scientists recently discovered that our ancestors, who had just learned to walk on two legs, also had a larger brain than previously thought, and the skulls of ancient children were also soft.
Previously, scientists were sure that this feature developed in us much later, and that our upright posture is only a consequence of the development of the brain. And now, it turns out, everything was exactly the opposite - at first we learned to walk on two legs, as a result of which there was a need to change the birth canal. This led to the development of the soft skull of babies, which in turn was followed by increased brain development, and now our brains can grow up to two years.
4. Hallucinogenic mushrooms were made from a monkey
One of the most controversial theories about the development of the human brain was put forward in the early 1990s by the American philosopher, ecologist, and lawyer Terence McKenna.
According to this theory, an ancient man stumbled upon unusual mushrooms somewhere in North Africa and decided to try them. The mushrooms turned out to be hallucinogenic. They caused bright, strange visual images in the central nervous system of ancient man, requiring understanding and analysis. This pushed the primitive brain to intensive development, and gradually new structures were formed in it. It turns out that thanks to the mushrooms, man has become a creature thinking in images. Then symbols arose from images, and from symbols - a stone's throw to connected speech.
That is, according to McKenna, the hallucinogenic mushroom is the very "missing link" that allowed the monkey to become a man.
Nobody has ever taken McKenna's theory seriously in the scientific world, nobody has been testing it, so there is currently no real data that could support it.
5. Meat and fire have played an important role in the development of the human brain
According to the theory of Harvard anthropologist Richard Rangham, meat cooked on a fire played a huge role in the development of the human brain.
Based on the evidence we have, we can assume that man began to build fire and learned to use it for cooking around the same period when his brain size increased, intestines, jaws and teeth decreased.
Cooking made it possible to spend less time and energy on food, and get more calories from it. And the human brain, as you know, consumes about a quarter of all the body's energy, and it got the extra calories. Therefore, food processing has proven to be extremely important for brain development.
A person no longer had to spend half a day chewing tough meat. And the resulting free time could be spent usefully - on the creation of tools, for example, or tillage. Or to communicate with their own kind.
6. Our ancestors were completely schizophrenic
In the 1970s, psychologist Julian Janes put forward a theory of what he called "bicameral intelligence."
Relying on ancient literature, Jaynes argued that the ancients did not have the consciousness we are used to - they did not plan their actions, did not make decisions. All their actions were subject to the instructions of the "gods" or "voices".
Janes concluded that the mind of our ancestors was "bicameral", which was due to the bicameral structure of the brain. In familiar situations, a person was guided by habits and instincts, and when a problem arose that required a non-standard resolution, the same “second chamber” located in the right hemisphere was connected.
According to Janes, the human brain is generally two separate organs. The left hemisphere is responsible for performing everyday tasks, the right hemisphere for memory and solving "special" problems.
In the ancients, Janes believes, unlike us, the hemispheres were not directly connected. Consequently, self-awareness was not available to them.
But the right and left hemispheres were associated with the language center in the brain, which explains the occurrence of hallucinations. That is, one half of the brain "broadcast", and the other perceived this information as a "voice from above."
Janes believes that the phenomenon of an "imaginary friend" in children, mental disorders associated with "split personality" can be considered a kind of remnants of such consciousness. In addition, numerous stories about some unexplained mental phenomena that arise in stressful situations work on the theory of Jaynes.