Why Don’t Humans Have Two Brains?
Most human organs and body parts come in pairs. Two hands, two legs, two lungs, two ears, two eyes, two kidneys, etc. So, why didn’t humans evolve two brains? And would having two brains make us more intelligent?
For a starter, many people hardly use one brain, so having two of them would be a waste of space and biological matter. But there is much more to this. Take a computer for example. You could upgrade your hardware. Add more RAM, bigger hard drive, multiple graphics cards, etc. The speed and performance will increase, but the computer will consume more energy. It will require more electricity to run. If you did this to your laptop, you would drain the battery much faster!
The brain consumes 20% of the energy produced in the body. Just imagine, a single organ consuming 20% while the rest of the body uses the remaining 80%. So, having two brain means your body will need to produce more energy to run both of them simultaneously. This energy is delivered to the brain in the form of oxygen. Your lungs help load your blood with oxygen while your heart pumps this oxygenated blood into the brain. Without sufficient amount of oxygenated blood, your brain won’t function properly. With two brains, you would need to increase your lungs’ capacity to oxygenate more blood, and your heart must also deliver more blood to the brain. This would put a strain on your lungs. Plus, a single heart might not be enough to deliver that amount of blood into your two brains.
When you donate one kidney, the second one will work harder to keep you alive. Perhaps with two brains, your lungs and heart’s capacity would go up, but this would reduce your life expectancy because these organs will be overworked. Not to mention, they will also require energy of their own to do this job, and this means you will have to consume more calories to keep them running.
Generally, the recommended daily calorie intake is 2,000 calories a day for women and 2,500 for men. So, if you convert the 20% energy the brain consumes into calories, that would be the equivalent of 350-400 for women and 400-500 calories for men during the resting state. So, having two brains would require you to double your daily calorie intake to meet the brains’ energy needs. It’s going to take a lot of work for your digestive system to process this many calories into useful nutrients.
There is another part of the body that needs to be adjusted to accommodate two brains: the skull. Naturally, having two brains with the current size would require a bigger skull! The skull’s shape and size take millions of years to evolve and accommodate new structures. So, technically having two brains would have delayed our evolution by a bit.
Clearly, it wasn’t ideal for humans to have two brains because that would require several structural and functional adjustments in our anatomy. It would have also caused major changes in our lifestyle, leading to a faster way of exhausting natural resources. Hence, having two brains was likely omitted through natural selection and humans ended up with a single brain. In fact, if you use it right, one is enough. Having two brains isn’t needed to achieve higher intelligence or have a more powerful memory. That’s because brain size doesn’t matter.
Intelligence and brain processing power are determined by several factors. The first one is neuron density, which refers to how many neurons you have in a given area of the brain. The more neurons you have, the more intelligent you’re likely to be, which is why smart writers and showrunners agree that Game of Thrones season 8 sucked, big time! The second factor is neural connections, which refers to the way your neurons are wired. Some of them are wired to facilitate faster exchange and processing of information, hence some people are smarter than others. And finally, your intelligence is determined by the way your brain regions communicate with one another and the extent of this communication.
There is a condition called split-brain or callosal syndrome where the two hemispheres of the brain are disconnected. When you cut the corpus callosum (the part of the brain that connects the left and right cerebral hemispheres), a person would start to behave as if there are two people inside making independent decisions of one another. This does not equate having two full brains because the left and right hemispheres coordinate with each other to help you sense the world around you. Hence, we can’t consider this as having two brains.
All in all, humans don’t have two brains because - evolutionary speaking - they don’t need to. We just need to make use of the one we already have. That would be a big achievement! And finally, make sure to perform different mental exercises that can increase your brain power. Start by learning a new language.
~ Hashem
#Experienced Negotiator (Music & IT) & #Experienced Inside Sales (IT) #Human Being #Empathic Problem Solver #Perpetual Learner
3 年Really great post, Hashem Al-Ghaili! ???? I am going to share it for you!
MEDICAL DOCTOR, ENTREPRENEUR, Coach, Influencer and Mentor
3 年BALANCE IS THE KEY.
CEO/MD at GRAM
3 年Bipedalism narrowed birth canal due to structure of the pelvis, even one brain passing through was a problem forget two. Our ancestors brains enlarged to accommodate the faculty of #language. #Bipedalism played a major part, walking on all four limbs to just two, this transition led to the #obstetric_dilemma due to changes in the female reproductive system, standing upright meant narrowing of the birth canal due to change in the structure of the pelvis, bipedalism and the brain expansion was a concurrent evolutionary feature. One adaptation was openings in the skull called #fontanelles, the #anterior_fontanelle enabled the two frontal bones of the skull to slide past each other, this helped compression of the head during birth, facilitating its passage through the birth canal, our anterior fontanelle remains open for the first few years of life, allowing for the massive increase in brain size, which occurs largely during early life, and it completely close by about two years of age, at which time the frontal bones have fused to form a structure called the metopic suture. In the chimpanzees, brain growth occurs mostly in the womb, and the anterior fontanelle is closed at around the time of birth.
Business Consultant, BEESWAX INFLUENCERS. A Social media Consultancy
3 年The gut is the second brain.
Retired, but brain is still working. (RF and Space Craft Subsystem Engineer)
3 年The strange thing is that everything that occurs twice is symmetrical paired mirror . The left hand is not simply a copy of the right hand. It is exactly the same with the ears, legs, kidneys and eyes. And we do have two mirrored brains to. It is so complicated to let grow complex body parts mirrored. If you think about in to the detailsit definitely it can not be a result of chance. It hase to be engineered and designed.