When you imagine an alien , what do you see?

No one really knows what aliens look like, but we all have similar opinions about them. It is usually a creature with a large head, long arms and legs, and large eyes. For example, cute animal creatures such as Baby Yoda, or what little gray man, little green man, etc.

But according to scientists' groundbreaking research on the basis of evolutionary biology, they believe that aliens may have evolved in a similar way to life on Earth , and even more similar to humans than we thought .

It is possible that natural selection could happen on other planets!

A 2022 study by the University of Oxford suggests that the natural selection process that created the species we see on Earth is likely to occur on other planets as well. Natural selection is a process outlined by Darwin's theory of evolution, which shows that species best suited to their environment are most likely to survive to pass on their genes. On Earth, this has led to billions of years of human evolution. But in another world, scientists think life could be radically different based on conditions on Earth, but should develop an important protective mechanism for the brain.

Look at the incredible diversity of life types on Earth, all of which have evolved within the same planetary environment. It's hard to believe that an alien species from a completely different biochemical base could happen to have two arms, two legs, two eyes, ears, nostrils...even two genders, warm-blooded, etc. But for intelligence, one would assume brain volume, so the body needs some sort of protective mechanism to protect the vital brain - something like an exoskeleton or a skull.

In order to make tools, they need some sort of manipulable 'finger', such as a finger (not necessarily a symmetrical thumb, but possibly a wrappable tentacle). There must be a reproductive system, but it can be budding, seeding, fission, spawning. They need some kind of sensory system, similar to eyes, ears, olfactory organs, but their "eyes" evolve to the peak spectrum of their planet for the star.

Do they live in the sea? In the clouds of a gas giant? on land? in the desert? in the jungle? They need a way to eat or expend energy, and also need to excrete waste.

Sam Levin, a zoologist at the University of Oxford, said: "We still can't say whether aliens would walk on two legs or have big green eyes. But we believe evolution provides a unique additional tool to Trying to understand what aliens will do is like, we've shown some examples of the strong predictions we can make with it. By predicting that aliens go through a "major shift" - that's how the complexity of Earth's species arises , we can say that there is a degree of predictability in evolution that will make them look like us."

ps: Events of "major shifts" -- events that drive the evolution of different species. This happens when single-celled organisms evolve into organisms made up of multiple cells. For example, billions of years ago, all life on Earth had a last common ancestor, or LUCA for short. However, when organisms faced "major shifts" in how they access food, some survived by evolving to meet these challenges, becoming more complex while outlasting their competitors, culminating in what is known today as human beings rise.

How likely is it that alien life resembles us?

Arik Kershenbaum, a zoologist at the University of Cambridge and an adviser to METI (a think tank on the subject of extraterrestrial information), said that the reason why humans imagine aliens is actually asking: aliens How many will there be like us? How likely is it that alien life is like us?

Guide to the Galactic, he argues that using terrestrial evolutionary biology is the best way to portray interstellar life. The book describes studies of animals such as rock hyraxes and dolphins in Israel, and wolves in the American West, leading to the conclusion that if you go back far enough, there is a connection between any two individuals of any species. Any alien life would have to develop some form of social cooperation and technology and a way to communicate with each other (if not us).

If the problems animals face on Earth are similar to the difficulties faced by other planets, and there are not infinitely many solutions to specific problems like getting energy from the sun and stars, then planets will tend to similarly evolve solutions to similar problems on different planets .


Take Saturn's two interesting moons, Titan and Enceladus , both of which have the liquids necessary for the chemical reactions that give rise to life, but both moons are in very different circumstances than Earth. On Enceladus, liquid exists in the form of a subsurface ocean beneath a thick crust of surface ice. Instead, Titan has liquid on its surface, but in the form of liquid natural gas, specifically methane and ethane.

On our blue planet, many marine creatures live on the bottom of the sea and come up to the surface to feed. Perhaps the opposite would be true for any life in Enceladus' oceans, in which case the surface ice crust acts as the seabed. In addition, the communication methods of alien life may also be different, perhaps through sound, light and chemical substances, and even magnetism and electricity. Such as whether the different pitches of wolf howls constitute a complex language, one based on sounds rather than words.

Disagreement: Real aliens must not be like us!

Acknowledging that evolution may apply to any world with competing creatures and limited resources doesn't really help us picture aliens. A more productive approach might be to consider the mechanism of what biologists call convergent evolution: Similar environmental conditions often lead to similar forms of evolution. If we assume that the rise of diverse plant and animal life requires the presence of liquid oceans, a thick atmosphere, and land, then these conditions are sure to sink into Earth thinking. Ocean predators have streamlined bodies, land creatures are more likely to have legs than wheels...


We can't write a cosmic bestiary just by invoking biological mechanics. If you go back to Earth 400 million years ago, where are the trilobites in those multicellular fauna like today's animals? For alien life, we need to really find it, otherwise it's all bullshit!