The Dominance of Homo Sapiens
We were contacted by a small publication of the name “Nutshell Science” asking if we would be interested in republishing one of their articles. They are comprised largely of high school students living in the People’s Republic of China. They were particularly eager and we believe that sharing this piece of theirs will help further their ambitions. You can view the original text in Mandarin on their publication here. Please be forgiving of the lack of idiomatic accuracy given the sharp difference between Mandarin and English.
Since different human species once coexisted, what has led to the dominance of Homo sapiens? Environmental, climatic, topographic factors certainly have contributed in the extinction of other human species, but the Homo sapiens have also led to some. Because of their advanced application of languages, Homo sapiens had better social compositions, religious forms, and techniques. As the population and territory of Homo sapiens grew larger, other human species couldn’t gain enough resources to survive, which led to the decrease in population and eventually the extinction. Meanwhile, for the sake of survival, Homo sapiens might also have declared wars to other human species on their initiative.
So, is there something other human species have left us? Nowadays, there is 1% — 4% Homo neanderthalensis DNA in European and Middle Eastern; there is 6% Homo Denisova DNA in Australian Aborigines, which means there were some human of other species, like Homo neanderthalensis and Homo Denisova, who had successfully reproduced viable offspring with Homo sapiens.
Brain, the most distinguishing characteristic.
Although differences existed in different human species, they all had one common — having significantly larger brain compared to other animals’. As early as 25 million years ago, the earliest human beings already had the brain capacity that was three times greater than that of the average of all the other mammals, and now six to seven times.
This seems to be normal: natural selection should have evolved smarter creatures. Humans cannot run as fast as a leopard, or be as strong as bears; neither could they fly, or dive; but are
capable of inventing things like cars, guns, airplanes and submarines. Isn’t intelligence the reason that human beings are at the top of the food chain? However, from the perspective of evolution, is that really the truth?
The structure of the brain is fragile, which is not good for motions; skulls are evolved to be quite heavy; the consumption of energy is even more significant. The brain is only 2% of the human weight but consumes 25% of energy while resting. Comparatively, ape’s brain only consumes around 8% of energy. This means that human must spend more time on seeking for food; not only that,
because more energy is allocated to the brain in order to function, the superiority of brain would then result in degeneration and atrophy of muscles. In fact, in more than 20 million years, human brains did not bring any advantages to human beings, which made natural selection theory an untenable reason to explain the evolution of human brains.
Upright with Free Hands
We have been told that the reason why human beings are different from other animals, especially apes which show quite a resemblance to humans, is that human beings can walk upright: for better visions to detect enemies and preys, for transmitting signals among partners, and for making tools and fires. And these uses secure human beings’ superiority.
Yes, of course, these are great. However, we will talk about another important trait that resulted from walking upright. Walking upright narrows people’s pelvis, which, to females, increases the difficulty of giving births and resulting in greater risk of obstructed labor. As a result, females who give premature
deliveries — since babies thus would have smaller and more flexible head — have greater chance to survive, and has become a common trait. However, premature delivery also has a disadvantage: immature of essential organs, and long time periods — infant, childhood, and adolescents in this case — is needed to become mature. This causes more burdens to adults and provides more opportunities to enemies to prey on babies. In fact, the babies of many other mammals that give multiple births of singlets like humans, such
as horses, elephants, are basically mature as soon as they are born, being capable of running in the first few hours.
However, the advantages are also significant. Since infants only spend limited time in mother’s body, babies have more time to be mature to shape and develop organs. Due to significant ability to comprehend and remember, human’s conscience is also building in these time periods. Thus, compared to other animals, humans have incredible plasticity. Being able to change
through educational and social interactions, humans thus are endowed with limitless possibilities and varieties.
Usage of Fire
Fire can drive enemies away, explore new roads, fertilize lands, lighten the night and etc. The most important one is definitely to cook the food. Fire can kill the microbes in the food to ensure humans’ health. It can also, thus, shorten the time of eating. Chimpanzee, on the other hand, spends 5 hours each day to chew raw meat, while human only spend 1 hour to chew cooked
meat. Fire allows people to digest more nutritional food, accompanied with results of shortening the length of intestines, lowering energy consumption and eventually help human beings to focus on contemplation.
Cognitive Revolution
100,000 years ago, Homo sapiens and Homo neanderthalensis interfered for the first time. A group of Homo sapiens moved to the Mediterranean for greater resources but failed because of the presence of Homo neanderthalensis and the cold weather. 70 thousand years ago, Homo
sapiens and Homo neanderthalensis interfered for the second time. This time, Homo neanderthalensis were evicted from the Mediterranean, which led to their extinction. 45 thousand years ago, Homo sapiens traveled to Australia across the Pacific Ocean. Later on, the first lamp, clothes, bow and arrow were invented; the first art piece was created; religions, community and
commerce appeared. All of these were caused by the cognitive revolution.
Nobody knows what had caused the cognitive revolution, why it only happened on Homo sapiens. What is widely accepted is that a genetic mutation changed the brain structure largely, and let us speak new languages and think in a totally new way.
New Languages
It is well known that many other animals in nature can also communicate well among species. For example, whales and monkeys can make noisy communication; bees and ants can act words out. Then why is human language powerful indeed? There are two complementary theories.
First, human languages are more complicated. For instance, bees and ants may say “I found some food”, while human beings can articulate “I found a burned boar hindquarters in the woods that are thirty minutes away from our home.” Second, humans spend time spreading information about human themselves. Humans spend a huge amount of time to gossip and using this massive database to train their brains. At the meantime, gossips actually endow humans the ability to know each other better, which allows
greater and more complicated corporations to exist.
Legends and Religions
The greatest change brought by the conscious revolution is that humans began to be able to share information that did not exist. If not mistaken, this is exclusive to Homo sapiens. Logically, “fictions” mean no direct material and earthly relationship. Begging and praying cannot fill people’s stomach. However, fiction does not mean so much imagination as the action of imagining together and brainstorming the resulted legends, religions, and myths. This is what gathers human to form a large and complex society; this is what accelerates the progress for humans to be leaders of the world.
These are all talents that we are born with: large brain, ability to walk upright, flexible hands, usages of fires or other tools, languages, complex social structure, imagination and creation. These are also the abilities that our ancestors spent millions of years, hundreds of generations to pass the edge of extinction and to acquire. These two simple words, “Natural Selection”, mean so much more.
I hope everybody can appreciate our great skills and make the best of it.
