In my earlier post, I talked about how our ancestors propagated the genes of increasing brain size even though the fruits of these did not seem so beneficial to human survival. Since scientific evidence is not conclusive, I have taken the liberty to speculate why increasing brain size may not have been so much adaptation but more of a gift to future generations.
It is like our ancestors knew that there was a need for the brain size to increase so that humans as a species can dominate the world in later generations. Otherwise there does not seem to be any plausible explanation as to why the following disadvantages were borne by not a generation or two but by thousands of generations.
Here is an excerpt from wikipedia (link)
The use of tools conferred a crucial evolutionary advantage, and required a larger and more sophisticated brain to co-ordinate the fine hand movements required for this task. The evolution of a larger brain created a problem for early humans, however. A larger brain requires a larger skull, and thus requires the female to have a wider birth canal for the newborn’s larger skull to pass through. But if the female’s birth canal grew too wide, her pelvis would be so wide that she would lose the ability to run: still a necessary skill in the dangerous world of 2 million years ago.
The solution to this was to give birth at an early stage of fetal development, before the skull grew too large to pass through the birth canal. This adaptation enabled the human brain to continue to grow, but it imposed a new discipline. The need to care for helpless infants for long periods of time forced humans to become less mobile. Human bands increasingly stayed in one place for long periods, so that females could care for infants, while males hunted food and fought with other bands that competed for food sources. As a result, humans became even more dependent on tool-making to compete with other animals and other humans, and relied less on body size and strength.
As you can understand from the excerpt, more problems are created by one adaptation after another. It is made to understand that the adaptation was a planned thing. That is where a lot of speculation comes into play.
With so much guesswork going on, there is no harm, I think in me guessing in a different way. I am hazarding a guess that our ancestors were following a plan. A plan encoded in the DNA to help create a perfect species. A species that can rule the earth and make the earth a better place.
In other words, our ancestors kept on living with the disadvantages of losing physical speed and strength, caring for the young longer than any other species, settling down to raise families and above all, learning to cooperate with other humans for survival.
In my next post on this series, I will talk about our most common and recent ancestor, the scientific Adam. In the meantime, let us not forget the sacrifices our ancestors made to help the next generations survive.
Thanks for reading and have a great day!