If this question is further expanded, it becomes: How did the first life arise? How did the universe arise?
Not only humans, other species will also have similar questions. For example, species like pigs, cows, sheep will also be asked the same question: How were the first pigs, cows, sheep born?
It should not be assumed that humans must be special just because they are intelligent, in fact, there is essentially no difference between the two questions “How was the first human born?” and “How was the first stone born?”.
However, as members of the human species, we still want to learn as much about our own evolutionary history as possible.
Does the theory of evolution answer this question?
From an evolutionary perspective, human ancestors originated from ancient apes tens of millions of years ago, of course the “first man” also evolved from ancient apes for a long time. If we continue to trace back in time, humans will also have earlier ancestors, such as great apes more than 20 million years ago.
It is important to emphasize here that the “ancient ape” mentioned below should not be confused with the apes of today, they are two completely different concepts. “Ancient ape” is just a human definition of human ancestors tens of millions of years ago.
The ancient ancestors of humans, ancient apes, lived for a long time in the dense forests of Africa, quite comfortably, with their ingenuity, they could easily avoid the attacks of wild animals and had few natural enemies. At that time, they tended to walk on four legs more and had the ability to climb, very strong
However, with the displacement of the African plate, the continent began to rise, especially in east Africa, a very deep rift valley appeared, dividing Africa into two parts, leading to major changes in the environment.
Forests continued to decline, forcing the ancient apes that lived in the forests of East Africa to live on grasslands. Without forest cover, the ancient apes’ survival advantage was largely gone, and their agile climbing skills were no longer used.
The most terrible thing is that the ancient apes that came to live in the grasslands had to face a large number of carnivorous birds and wild animals, mainly big cats such as lions and tigers. These animals run very fast, have a very strong bite force and are quite large in size.
Compared to these animals, ancient apes had almost no advantages, so at first ancient apes often became their meals.
In this harsh environment, many ancient apes began to seek out new forests and return to forest life. But a small number continued to live on the grasslands, and this group eventually evolved from walking on all fours to walking upright.
Walking upright had many advantages. The most obvious advantage was the huge energy savings, consuming only one-third of the energy required to walk on all fours. This meant that after walking upright, ancient apes were less dependent on food and could travel further to find food in a wider range.
In fact, although the ancient apes of that time had evolved to walk upright, their characteristics were more animal-like in every way. They initially did not know how to hunt and could only eat the leftovers left by wild animals.
Our ancestors were very fortunate to have evolved to have larger brain capacities and enough energy to meet their brain needs, especially when our ancient ancestors happened to learn how to use fire. So at a certain stage, the brain capacity of our ancestors began to increase significantly.
When our ancient ancestors evolved to the stage of Homo habilis (handy man), their brain capacity was around 700 ml. Biologically, the brain capacity of 700 ml is also determined as the dividing line between humans and apes.
Of course, 700 ml is clearly not a one-size-fits-all dividing line, and is also a vague concept, which does not mean that a brain with a capacity of 699 ml is definitely not “human”.
In fact, in general, the evolutionary history of humans can be divided into several stages from distant to recent: Hominoidea, Hominidae, Homininae, Hominin, genus Homo and Hominin.
Many people may not know, and even if they do, they may not want to believe, that gorillas living on Earth belong to the subfamily Homininae and not the subfamily Orangutan, while chimpanzees belong to the Homo family.
The Homo genus includes 8 species in 4 genera: Pongo; Gorilla; Pan; and Homo (modern humans).
The earliest species in the genus Homo is Sahelanthropus tchadensis. It is one of the oldest known species in the human family tree. It lived about 7 million years ago in West-Central Africa. Walking upright may have helped it survive in a variety of habitats, including forests and grasslands.
The genus Homo continued to develop and differentiate into many different branches, and it was not until the appearance of Homo habilis that it could be considered the “earliest human”.
Over a long period of time since then, Homo habilis has evolved into many different branches, such as Homo erectus, Homo sapiens, Homo rudolphus, up to the later pioneers – Neanderthals.
Different branches in the long evolutionary history are actually “cousins” of modern humans, but these “cousins” have different relationships to humans. For example, gorillas are relatively early “cousins” of humans, while chimpanzees are more closely related to humans. And Homo erectus, Homo protohuman, Homo heidelbergensis, and later Neanderthals and Denisovans are closer “cousins” of humans.
In the evolutionary history of mankind, many of our intelligent “cousins” have become extinct, leaving only the lucky Homo sapiens – the ancestors of modern humans.