Some would say that from the moment we stood upright and walked on our feet, we began a journey that ultimately would lead to our dominance. I believe what truly gave us an advantage over all other creatures was our development and use of language. Our ability to make sounds that can be formed into language is connected to us standing upright. As to why we stood upright, It could have been an adaption to see over tall grass in order to get an advantage over predators. A number of other mammals use the biped method for locomotion as their primary means of transport. Most are small, and Ape’s are among the largest, but all traverse the landscape upright for short trips and otherwise travel as quadrupeds.
While upright locomotion is slower than most quadrupeds, a small advantage is seen in the ability to rapidly change directions. The greater advantage is that walking upright saves energy and in turn means less time spent foraging for food. Spending less time looking for food means more time to find things to do with those fore limbs that are now free for other uses.
It’s not any one thing by itself that leads to the development of language, but a combination of events. Our primate relatives also stand upright, even if it’s only part time. So why is this not the “Planet of the Apes”? Because they can do something we can’t and as a consequence, we can do something that they can’t. Primates can drink and breath at the same time. Their windpipe (trachea) and esophagus are separate. The larynx is the valve that opens and closes to allow air to flow to the lungs. In primates the larynx is higher. In adult humans the larynx is lower than the esophagus and both share space in the pharynx. The advantage is that we can make funny sounds which are interpreted to be language. The disadvantage is you can choke to death if you don’t shut up while eating.
The ability to make sounds that can represent objects and things is key in our development of language. Babies start out with their larynx in a higher position, similar to that of primates. After a few months, the larynx of the human starts to move towards a lower position and continues through puberty until adulthood, which is in part responsible for the change in voice in adolescence. There is some indication that Sudden Infant Death Syndrome may be tied to this critical period of change. If we didn’t stand upright would this mutation have occurred? We’ll never know, but I suspect the answer is no. I believe the position of larynx is due to bipedalism. From that point the brain is slowly repurposed to fully utilize this new ability.
It is language which transforms communication from something that is static and of the moment, to the sharing of information in a way that permitted it to transcend time because it is transferable and portable. Groups of humans sharing, and transferring knowledge from older generations to younger generations resulted in humans being more than the sum of our born instincts. A discovery that a sharp rock can be used as cutting tool or that an animal bone can be sharpen to a point, is not lost after one generation. When one hunting party meets another, they share language and technology, either by accident or by intent.
This building of knowledge continued and accelerated when spoken language transformed into written language, and then to printed language. In the last twenty years the rate of change has gone off the charts. The reason… The arrival of the Internet. If you doubt me, Google it. In the last five years the evolution of social media has changed how we understand and perceive the world creating a type of social revolution. We are starting to realize that we are all one, with many different parts. Hopefully we will also realize that for each of us to truly be happy and healthy, no one part can be permitted to suffer.