When did we claim to be human in the long course of evolution? Are chimpanzees human?
In mythology, when we become "human", it is often accompanied by a unique moment. Eve plucked the fruit of the tree of knowledge and became aware of good and evil. Prometheus created people out of clay and brought fire to them.
Michelangelo's "Creation of Adam" | Source: Wikipedia
But in the story of the origins of modern science, there is no decisive moment of creation in evolution. Instead, humans emerged from earlier species from generation to generation.
Like any other complex adaptation, humans have evolved step by step over millions of years. Mutations appeared in DNA and spread throughout the population, and our ancestors slowly evolved into who we are today. Eventually, "we" appeared.
<h1 class="pgc-h-arrow-right" data-track="15" >01 Strange ape, but still ape</h1>
Humans are animals, but unlike other animals. We have complex language that allows us to express and communicate ideas. We are creative: we make art, music and tools. Our imagination allows us to think about the world that once existed, to dream of the world that might exist, and to rearrange the external world according to these ideas. Our social life is a complex network of families, friends, and tribes that are linked by a sense of responsibility to each other. We are also conscious of ourselves and our universe: perception, wisdom, consciousness, whatever you call it.
However, there is not much difference between us and other animals. Animals are more human-like than we think — or more human-like. We used to think that almost all of the behaviors that were unique to us could be seen in animals, even if they were not so well developed.
Gorillas also use tools to | Image source: Dean Bertoncelj/Shutterstock
This is especially true for great apes. Chimpanzees, for example, have simple gestures and verbal communication. They make crude tools, even weapons, and different groups have different tool kits — different cultures. Chimpanzees also have complex social lives and cooperate with each other.
We used to think of ourselves as absolutely unique beings, but as we delved deeper, we discovered a very different story. As Darwin argues in The Origin of Man, almost all of the strangeness of Homo sapiens, including emotions, cognition, language, tools, and society, actually exists in some primitive form in other animals. We're different, but we're not as different as we think.
In the past, some species were more like us than others—ground apes, australopithecus, Homo erectus, and Neanderthals. Homo sapiens was once the only survivor of a very diverse group of humans and archaic humans, including about 20 known species and possibly dozens more.
The extinction of other ancient humans erased all species that were between us and other great apes, leaving the illusion that there was an insurmountable gulf between us and the rest of the creatures on Earth. But now, the discovery of these extinct species has completely blurred that line.
<h1 class="pgc-h-arrow-right" data-track="131" >02 Human evolution</h1>
Our lineage may have parted ways with chimpanzees about 6 million years ago, but these earliest archaic humans looked almost completely human-like. In the first few million years, the evolution of ancient humans was very slow.
One of the first major changes was to walk upright, which allowed ancient humans to migrate from forests to more open grasslands and shrublands. Ground apes are members of the earliest known paleoanthropology family, and their brains are slightly smaller than those of chimpanzees, and there is no evidence that they used tools.
Next, Australopithecus appeared. They have slightly larger brains and will slaughter animals with sharp stones. Then came the noh, the size of the brains of ancient humans surpassed that of other great apes for the first time, and the tools began to become much more complex.
The core of the sharp stone piece has been cut off, and it is likely that it is a masterpiece of a capable person| source: the author
Since then, about 2 million years ago, human evolution has begun to accelerate, but the reasons are unclear. And so, Homo erectus appeared.
Homo erectus is taller and more like us in stature, with brain size about two-thirds of ours. They can make complex tools, such as stone hand axes. This is a major technological advance. Crafting a hand axe requires skill and planning, and it can also be a meta-tool that can be used to craft other tools such as spears.
Like us, Homo erectus has small teeth, which suggests a shift from a plant-based diet to eating more meat.
Hand Axe | Made by Homo erectus Source: Author
At this point, our evolution seems to be accelerating. Homo erectus soon followed by species with larger brains. These highly intelligent ancient humans spread across Africa and Eurasia, evolving into Neanderthals, Denisovans, Rhodesians, and ancient Homo sapiens. During this period, technology became more advanced, and ancient humans learned to make fires. Some objects that do not have a clear practical function, such as jewelry and works of art, have also appeared in the past 500,000 years.
The bones and DNA of some of these species are actually strikingly similar to ours. Neanderthals, for example, evolved larger brains over time, and by later, their brain sizes were comparable to those of modern humans. They may consider themselves human, and they may even say so.
Neanderthal-related archaeological records reflect some unique human behaviors, suggesting that their thinking is similar to ours. They were skilled and versatile hunters who knew how to use all their resources to create complex tools, making jewelry out of shells, animal teeth and eagle claws, and painting the art of cave paintings.
Neanderthal ears are similar to ours and can discern the subtleties of speech. We know that they have buried their dead companions and may even mourn.
It's reasonable to guess that they may be similar to us in many other ways, but they just fail to leave a record, such as they should be able to sing and dance, fear ghosts, worship gods, be equally curious about the stars, and tell stories. They must be capable of doing very kind and empathetic acts, but there are also acts of cruelty, violence and deception.
There are other species that we know very little about, but it is reasonable to speculate from the available evidence that they must be very similar to us.
Neanderthal and modern human skulls | Source: Wikipedia
<h1 class="pgc-h-arrow-right" data-track="132" >03 Love and War</h1>
One detail is that we still carry the DNA of Neanderthals, Denisovans, and other ancient humans today. Our ancestors met them and had children together. It also shows how "human" they are.
Although it is not impossible to capture women, to get genes into our group, we must not only mate, but also successfully raise children, and when the children grow up, they must also raise their children. Obviously more likely, this is the result of a voluntary intermarriage. Genetic mixing also requires their hybrid offspring to be accepted by the group, in other words, to be seen as completely human.
This is not to say that encounters between species are not biased or completely peaceful, but rather that we Homo sapiens are most likely responsible for the extinction of those species. But there must have been moments when we crossed our differences and found a common "humanity."
Finally, the facts tell us that while we did replace other archaic humans, it took a long time. The extinction of Neanderthals, Denisovans and other species took hundreds of thousands of years. If Neanderthals and Denisovans were really just stupid and inferior barbarians, with no language or complex thinking, then they could not have stopped modern people for so long.
<h1 class="pgc-h-arrow-right" data-track="133" >04 people on the edge</h1>
It is not clear why Homo sapiens replaced them. Perhaps it's the spark of creativity that gives us some advantages. But whatever the difference, it must be extremely subtle, otherwise we wouldn't have taken that long to win this game.
While we don't know what these differences are, our unique skull shape may provide a clue. Neanderthals had slender skulls with huge brow ridges. Humans have a spherical skull shaped like a soccer ball with no brow ridges. Curiously, in young Neanderthals, and even in juvenile apes, the smooth round heads characteristic of adult Homo sapiens could be seen. Similarly, juvenile skulls of wild animals, such as domestic dogs, have been found in domesticated animals: the skulls of adult dogs resemble the skulls of wolf cubs. These similarities are not only superficial, but also behavioral. Dogs behave like young wolves, less aggressive and more playful.
The comparison between Heidelberg and Homo sapiens | Image source: Procy/Shuttertock
We suspect, mainly a hunch, that the advantages of Homo sapiens may not necessarily be primitive wisdom, but differences in attitudes. We may retain childish behavior, which in turn may help us make our society bigger, more complex, more open, and more innovative, and then beat them out in the competition.
<h1 class="pgc-h-arrow-right" data-track="134" >05 But, what is it? </h1>
So far, I have avoided an important, arguably, the most important one. It's okay to discuss how our human nature evolved, but what exactly is human nature? If it is not defined, what is the study and understanding?
People tend to think that there is something that makes us fundamentally different from other animals. For example, we can go to the store to buy a puppy or kitten, but we must not buy or sell babies. The rules for us and for them are different. Even the hardest animal rights activists advocate for animal rights, not human rights.
We inherently think of ourselves occupying different moral and spiritual heights. However, it is difficult to find evidence of this fundamental distinction.
The word "humanity" means taking care of each other and sympathizing with each other, but it can also be said to be a mammalian quality. Mother cats also care about kittens, and dogs love their owners, possibly even more than anyone. Killer whales and elephants can form lifelong family bands. Neither emotional life nor relationships are unique to us.
Maybe consciousness sets us apart, but dogs and cats seem to know us, and they recognize us as individuals as if we recognized them. They know us very well, know how to make us give them food, or let them go out, and even come to pet and accompany us when we have a bad day. If this is not awareness, what is it?
Maybe it's our big heads that set us apart, but does that make us human? Bottlenose dolphins have bigger brains than ours, elephants have three times as many brains as ours, and human brains vary. Albert Einstein's brain was smaller than the average Neanderthal, Denisovan or Rhodesian average. So brain capacity is not the key to us being human, and something outside of brain capacity makes us human.
Does the cat know that it is itself in the mirror? | Image source: Vilvarin/Shutterstock, CC BY-SA
We can also try to define human nature with higher levels of cognitive abilities, including art, math, music, and language. This raises a strange question because there are differences in human beings' ability to do these things. I'm not as good at math as Hawking, not as good at invention as Jobs, not as good at articulating as Martin Luther King Jr. Am I more "inhuman" than they are in these respects?
If we can't even define human nature, how can we really say where it started and where it ended, or think that we ourselves are supreme and unique?
Nor are we necessarily the logical end of human evolution, we are just one of many human family species.
The nature of evolution means that living things cannot be grouped into neat categories. The gradual transition from one species to another, with each individual within a species slightly different, gives evolution a chance to bring about change. But it also makes it particularly difficult to define human nature.
Because of natural selection, it is difficult to make a strict classification of all living things, because evolution is constantly changing things, creating diverse species, and diversity within species.
Admittedly, in some ways, our species is not so diverse. Homo sapiens has less genetic diversity than the average strain of bacteria. Compared to sponges, roses, or oaks, our bodies vary little in shape.
But in our behavior, human nature is very different. We are hunters, farmers, mathematicians, soldiers, explorers, carpenters, criminals, artists... There are many different ways of life that human beings have, and each of us must define and discover what it means to be human.
Ironically, it is this undefinable humanity that is one of our most human characteristics.
Nicholas R. Longrich (Senior Lecturer in Paleontology and Evolutionary Biology, University of Bath)
Original link:
https://theconversation.com/would-we-still-see-ourselves-as-human-if-other-hominin-species-hadnt-gone-extinct-166759