Let me ask you a question about what an alien should look like, and I bet you answer, "Well, green, short, thin and with huge black eyes."
Who came up with this? Why exactly green and not red or purple? Why is it necessarily skinny? Anyway, who told you that an alien must be organic?
Aliens are a topic that is still beyond the control of our minds. That is, of course, we can well fantasize, but suddenly another form of life from a distant planet unknown to us will look so unusual that we will not even see life as such in its appearance. And are there any criteria that can give out life in such an unusual representation for us?
There is such a science - astrobiology, it studies life on other planets. This science operates with knowledge from biology, chemistry, physics and astronomy, is considered one of the most promising today and attracts huge investments from NASA and private investors.
Astrobiologists assume (or maybe even already know) what an alien should be like. More precisely, how it should look. It turns out that external data is the first thing that helps us distinguish living organisms. So the main criterion for astrobiologists is complexity and purposefulness in appearance.
Living organisms have many parts in their composition, the functioning of the organism as a whole depends on their work. People have kidneys, hearts, eyelashes, nerve endings - all these parts of our body are different, unlike others.
In their composition, they are complex, and together they form an even more complex organism - so that we can function - eat, move, think, see, etc. Now let us compare some cliff that amazes the human eye with its complexity, the number of patterns and components, with unicellular organism, which itself can divide, multiply, etc. It would seem that it is more difficult? And in this unequal battle, the cage wins!
The fact is that only a living organism sets itself the main goal - survival. This is what makes him move, get food, reproduce. That is why many organisms (complex and simple) have their own defense mechanisms. It is survival and reproduction that are the main criteria for life in general.
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Agree, if you get a photo of an alien, you will certainly look for this most notorious adaptation on it. And you will certainly understand where in the photo is a pile of stones, presented in the form of a figure, and where a living creature, albeit from another planet.
Astrobiologists call the second defining criterion the action of natural selection.
As we all know from school biology lessons, natural selection only takes place when an organism fits three important aspects: variability, heredity, and survival.
Take a fictional alien species for example. For example, "long-eyed" have eyes set on a special process in order to see better and further. With such "long eyes" the aliens are born with their children (example: heredity). "Long-eyed" with long, appendages with eyes have the opportunity to see the advance of a predator from their burrows faster, thus they can better protect their offspring, which automatically expands their population (example: survival rate, which directly depends on variability). As a result, the population of "long-eyed" will have even longer processes on which the eyes are attached.
This process forms the structure of a living organism - the most adapted organisms are selected so that in the future the population would include individuals that would be ideal for survival and reproduction.
If we recall the conclusion of astrobiologists about the uniqueness of life, then we can draw a parallel - the only way to get a unique structure of life is natural selection. Aliens will be the result.
Since natural selection obeys some laws, astrobiologists can use their knowledge in this area and predict the appearance of aliens.
Of course, it is impossible to get a living organism without passing through natural selection. Even an alien, which we would rather call an alien half-robot, passed a certain selection. However, let's imagine some kind of molecules from another solar system. Let's say they copy themselves (example: heredity), but the copies are too similar, that is, they do not reflect the actions of variability or survival. This will not be called natural selection, and the molecules themselves cannot be considered life.
Without the process of variability, the molecules will retain their appearance the same, and will not adapt to the changing conditions of the external environment. This means that they will not be able to develop into a more complex organism. In addition, the very fact of the vital activity of such molecules will be very short, since they will not be able to withstand an aggressive external environment and will disappear after a certain period of time.
And the last theory of astrobiologists is the octomite alien. Let's try again to present a possible photo of the alien, his appearance. In the photo, we are unlikely to understand how many arms or legs he has, we will not count the number of eyes, etc. But it is thanks to natural selection that scientists can say with confidence that the form, goals and path in their evolution in an alien must be in agreement with each other. friend.
The editorial staff of Aeon came up with and tried to depict what an alien might look like in theory (she even came up with a name for it - "octomite").
It would be extremely difficult for an ordinary person to understand what is in front of him and why it has such forms. But an exotic alien for us
becomes quite logical for scientists who, with the help of evolutionary theory, can explain almost everything that they saw in the photograph.
NIKITINA ELENA
