Arjun Khemani

Everything we do, every thought we’ve ever had, is produced by the human brain. But exactly how it operates remains one of the biggest unsolved mysteries, and it seems the more we probe its secrets, the more surprises we find.

Neil deGrasse Tyson

The other day in biology class while we were studying something about the brain, I wondered, how on earth did the human brain even evolve?

We know that the human brain has really progressed a lot. It has grown much bigger in size too. History and evolution tell us a giant growth spurt in the size of the hominid brain hit some 2 million years ago (which is that of the brain of our great ape ancestors – aka the animals of the genus: Homo – human, not just referring to Homo sapiens) . And human brain sizes have almost tripled since then.
But how? Also, why?

The above graph shows the varying sizes and growth at different times of the hominid brain. An exponential continuous increase in brain size occurring from about 2 million years ago till date for the species of genus Homo.

Dinosaurs were amazing. And huge. But apparently they had very small brains for their humongous body, as well as generally. Perhaps that’s one of the few reasons there’s a possibility they probably never looked up at the stars. And hence never expected something so large to fall down from space which would wipe off their entire civilization. R.I.P. dinos.

The one thing responsible for the general improvement of an organism over time (as we see it) is coined evolution. As is often defined, evolution is descent with modification. It is change in characteristics coming from a common ancestor through the process of natural selection. Through the process of natural selection, a wide range of characteristics were merged and the human genome started becoming more powerful and intelligent. Genome is the complete set of genetic information in a body. And as we mixed genes, different traits combined into one, then those combined with even different traits. And the process continued. Giving us, as a result, an evolved species with multiple good traits.

Well, there surely mustn’t be just chance or simple luck playing a role here, right? So we know how we got to such an incredible phase in technology where I’m able to communicate to you—which itself is a huge thing on it’s own—wherever you may be in the world through completely wireless, amazing IT. Simple answer: evolution. Our brains continuously adapted to doing more complex stuff all the way from creating fire, simple tools, metals, the wheel and inevitably we made the Internet! We sent people to the moon. And handcrafted robots and delivered them to Mars. And we’re on the brim of completely defeating an epidemic (through vaccines and physical distancing!).
But why? Why just us? Although it seems vital to think that chance shouldn’t be the only way we became the tyrant animals here on Earth, there doesn’t seem to be any good explanation for why we, just another species closely related with chimpanzees, now rule the world.
I like thinking in terms of cause and effect. I don’t feel good thinking in a way which states human beings were just “lucky” to be the right organisms to rule Earth. Luck is created through involuntary actions. Why are we lucky?
There must be a reason for why we stood out. Why we stood out and not our closely related chimp brothers and sisters, or other animals like lions, dogs, wolves, snakes, whoever.

So, what is that reason? Why are we such incredible species? Why do we study our brains and brains of other creatures, and they just go about their lives normally, why don’t they study us?

I think the why part of the question in a sense boils down to the how. We evolved. “Why did we evolve so drastically when the rest were just that, the rest?” Maybe because we had all the right requisites for leading. We were gifted. “Why is that, why were we gifted?” Well, if anybody knew that, I’m sure we would have named them God.
Some might reason it’s pointless to study evolution and discover why we are special today. They may say that we shall enjoy that specialty in the short period we live here on Earth. And they would be right. Partly. Partly, though they would sound not quite right because we, as such great animals want to understand . We love feeding our curious desires to really important questions. We want to believe. We want to know the meaning and purpose of life. I think that’s what makes some strive to find answers.

Though whatever happened, I think we ought to be satisfied being humans with such an incredible brain and stuff. It’s amazing how we think. And it’s amazing we have so many neurons in our cerebral cortex.

References and Footnotes

The Evolution of the Human Brain (YouTube)