Children are very fond of thinking about who aliens are like. Well, adults working in the film industry show all their irrepressible imagination, portraying the appearance of space aliens on the screen. And only scientists scrupulously analyze the facts, trying to compose a reliable portrait. If aliens do exist, could they be like us? Or maybe they represent terrible monsters or creatures that are simply impossible for the human mind to imagine? The answers to all these questions are deep and depend on the understanding of evolutionary processes.
Humanoid aliens have taken over the minds of Hollywood filmmakers
Why has the subject of humanoid creatures become so popular in the fantasy film industry? The answer to this question lies in the technical capabilities of the film crew. Modern special effects can reproduce any of the most outlandish creatures in the frame. However, films that were filmed 20 years ago were deprived of all this. So I had to portray a hypothetical extraterrestrial life form with the help of actors dressed in alien costumes.
However, even now, with hundreds of millions of dollars in space blockbusters' budgets, the humanoid theme remains one of the most popular. Most likely, unseen characters are perceived worse by the viewer due to the lack of emotional connection with earthlings. One of the most striking and successful examples of the depiction of extraterrestrial life is the legendary film "Avatar" by James Cameron.
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Where to look for answers?
Unfortunately, we cannot go to plow the vastness of the Universe in order to study alien forms of existence. All the knowledge that we can get is here on Earth. If all life on the planet has a common origin, we probably all had one ancestor. Who is this mysterious creature that gave life to 20 million species of living beings that now inhabit the Earth? If we manage to establish the truth, perhaps we will get closer to the solution. For this we will plunge into the deep history of the existence of the Earth.
Before the Cambrian explosion, strange creatures lived on the planet
All living organisms living on our planet are usually divided into 30 main groups. However, scientists believe that before the Cambrian explosion, which occurred about 542 million years ago, there may have been a greater variety of species on Earth. Archaeologists have found the remains of ancient fossil animals called opabinia. From the bones found in the deposits of the Cambrian period, one can judge the amazing structure of the animal. The simulated image could be very popular with children. On the head of the creature were located as many as five processes with eyes. Isn't it a hero for a sci-fi movie?
Thought experiment
When do we start to think about what would happen if we could turn back time and rewind it, like frames in a film strip? Many of us believe that our entire life would have turned out differently. One has only to change one important event - and the whole subsequent chain will collapse. This method is often used in many branches of science, and it has its own name - thought experiment. Biologist Stephen Jay Gould also used this test, but in relation to evolutionary development. According to the scientist, if we were able to rewind the film of life far back, at a time when life forms were just emerging, history could have a completely different scenario. Evolution is so important that even the replacement of an insignificant link in the chronology of events could turn our entire existence today.
Some creatures survived the Cambrian explosion
If after the Cambrian explosion no creature managed to survive, today our world would not be inhabited by fish, reptiles, amphibians and even mammals. In fact, we live thanks to pikayas, small chordate animals that have managed to adapt to new conditions. In the event of the death of this primitive creature, the emergence of intelligent life on Earth could be questioned. But if any other group of animals remained alive after the Cambrian explosion, it is likely that you and I would have five eyes instead of two. Now think about why aliens have to be humanoid? If any link in evolutionary processes is capable of turning everything upside down, it is likely that the history of other civilizations could not have developed according to similar scenarios. Which meansthat extraterrestrial beings can look anything. They may not even remotely resemble humans.
Evolutionary alignment
Evolutionary biologist Simon Conway Morris believes that the answers to our questions are rooted in evolutionary alignment theory. Thanks to this process, even completely unrelated animals are endowed with similar features. This is easy to prove by comparing the streamlined shape of dolphins or tuna to the extinct ichthyosaurs. Each of these species evolved autonomously from each other, but they all needed rapid speed underwater.
Alternative biochemistry
If you look at the origin of life from the point of view of the science of biochemistry, you can highlight the main chemical that contributes to this process. Carbon easily forms stable compounds with other substances, which, however, are easily destroyed. What if life could have originated from other chemical elements? For example, sulfur, boron, or silicon could well expand our understanding of the origin of life. These elements are capable of forming less stable compounds, but they do an excellent job with this under conditions of earthly temperatures. The only thing we know for sure is that no form of civilization is possible without the participation of water resources. Otherwise, the aliens must have some other solvent.
What is needed for development?
But if life has arisen, it must develop continuously. This requires mechanisms for storing and accumulating information, which in our case are performed by DNA and RNA molecules. If all these conditions (the presence of an element easily forming a connection, water and information storage, as well as comfortable temperatures of existence) are met, we can talk about the possible origin of life on other planets. Now let's take a look again at the history of our planet. Once upon a time, life here was literally stuck at the level of single-celled beings. It took about three billion years for the higher forms of existence (multicellular) to appear. What if primitive organisms already live on other planets, but they are still far from the stage of higher intelligence?
What could be the structure of the bodies of alien beings?
If you think about the alleged body structure of alien creatures, in this case, it is also necessary to draw parallels with terrestrial inhabitants. Basically, terrestrial animals feed on each other or on autotrophic organisms. Throughout their adult life, many species are puzzled by the search for food. Living things need a head, where the food inlet is located, and a tail. Chewing requires teeth and jaws, and these body parts can also aid in hunting. For the movement of individuals on a solid surface (soil), a special structure of the limbs and, if possible, bilateral symmetry is necessary. In this regard, many internal organs must be paired. Everything else is a matter of chance. So, for example, a person has five fingers on his hands and feet, while our ancient ancestors had seven or eight.
Conclusion
A too vague picture looms before us. If evolutionary biologists are able to understand what scenario is the development of organisms (functional or random), this will help to more accurately determine how alien life differs from terrestrial life.
Inga Kaisina