For technically advanced and intelligent beings to inhabit a single celestial body is like “keeping all eggs in one basket” or all savings in the securities of one corporation. Any large-scale accident can quickly devalue stocks or make the planet uninhabitable, extinguishing the fragile light of meaningful life - perhaps the only one in the entire universe.
It could be a massive asteroid impact or a volcanic eruption, a nuclear conflict or a global pandemic - disaster films (and indeed life) provide enough options. But if humanity is really reasonable, then it will have time to prepare for such a development of events. Actually, the process is already underway.
Elon Musk promises to send the first manned mission to Mars in the 2020s, and by 2050 to build a whole city here. Projects of Martian settlements compete in international competitions, space agencies of different countries are working on their options. Enthusiasts are actively discussing the technology of growing potatoes on Mars, tested by the hero of Matt Damon in the movie "The Martian".
Indeed, the conditions on the "Red Planet" are strikingly different from the usual on the "Blue". They will require not only new methods of soil preparation and hilling of tubers, but also new people. The more generations grow on Mars, the more noticeably they will differ from their relatives on Earth. Over time, local residents can be easily distinguished into a separate “subspecies” of Homo sapiens. And later they will finally turn into a new species - let's call it “Martian man”, Homo mascus. Let's try to predict what its representatives will look like.
Chunky silhouette
At first, the colonists on the Red Planet will be few and far between. Therefore, the first evolutionary phenomenon they will encounter is the "founder effect." Indeed, due to the usual statistics, the genetic diversity of such a group will be lower than that of the entire vast population on Earth. Therefore, even a slight deviation from the average will appear brighter and be passed on to future generations.
Promotional video:
The specific manifestations of the effect depend on which genes the founders of the new population carry with them. This can be hair color, eye shape, growth or physiological features invisible from the outside. But other adaptations of people to life on the new planet are determined by local conditions and look more predictable. For example, Scott Solomon, a professor at Rice University, author of the book Future Humans, believes that due to the reduced gravity, the skeleton of future Martians should become more … durable.
Indeed, it is known that under microgravity conditions in near-earth orbit, the bones of astronauts demineralize, losing 1–2 percent of their strength every month. On Mars, the attraction is not so weak, but still it remains almost three times lower than the Earth's. According to Scott Solomon, in 2-3 years people here will lose up to half of their bone mass, and women who have survived pregnancy will lose even more, since they have to spend additional amounts of calcium to form the skeleton of a child.
Such weak and fragile bones pose a great danger to survival. Therefore, it can be assumed that the skeleton will become heavier in the course of adaptation to Martian conditions. The bones that fold it will become larger and more massive, like those of our distant ancestors. The squat, stocky physique may become one of the most visible and recognizable features of the inhabitants of Mars.
Orange skin
Moreover, Mars has neither a global magnetic field nor a dense atmosphere. As a result, the planet's surface is constantly being watered by high-energy particles of cosmic radiation, protons of the solar wind, ultraviolet photons, which are deadly for any life. It goes without saying that dwellings and work spaces, and even spacesuits, will provide people with some protection. Nevertheless, the level of radiation to which the settlers on the Red Planet will be exposed will be many times higher than any earthly norms.
Such conditions will require more effective physiological protection of the body from radiation. On Earth, the pigment eumelanin is used for this, which makes the skin of some people brown-black and neutralizes ultraviolet rays. However, Homo mascus will need protection much more than even the inhabitants of equatorial Africa, and may well become even darker-skinned. However, their evolution can move along a different path.
After all, while most animals on Earth, including humans, use melanin to shield UV rays, plants are more likely to rely on carotene derivatives. Our body is capable of assimilating and modifying such molecules, although it uses them for completely different tasks - we need carotenoids, like vitamin A. On Mars, under strong selection pressure, the same compounds may well take on the function of protection from radiation … In this case, the skin of local residents will eventually turn not black, but red-orange.
Artificial microflora
A separate issue is the microflora of the future inhabitants of Mars. After all, on Earth, we live in the closest and most vital interaction with the bacteria that inhabit our intestines. Their healthy set begins to form from the first minutes of life and stabilizes gradually, as they meet with various microbes in food and around us. But for the Martian settlers, all these conditions will be completely different, which means that their microflora will also become different.
It is difficult to say what these changes will be. It can only be noted that the diversity of intestinal bacteria is reduced among residents of modern megalopolises. This means that the Martians, who will live in even more controlled and "clean" conditions, the microflora will be even less diverse. The absence of beneficial bacteria can lead to the development of metabolic disorders, including obesity and diabetes, as well as immunity.
Moreover, experiments on laboratory rodents show that completely sterile animals are completely unable to develop normally. For people on the neighboring planet, this will be unacceptable. Therefore, they will have to create and be sure to use drugs to normalize microflora. So this effect of life on Mars will largely be leveled: the intestinal microbiome of the settlers on the Red Planet may remain approximately the same.
Painful glasses
However, Scott Solomon fears that living in a controlled and near-sterile environment will have a devastating effect on the immunity of future Mars inhabitants. Never in their lives will they come across a multitude of bacteria, viruses and allergens with which we on Earth interact from birth to death. Without constant stimulation, the immune system is not able to form normally - and even in astronauts in orbit, it manages to noticeably weaken.
As a result, a visit to Earth, or even an encounter with earthlings, who are forever surrounded by whole clouds of bacteria and viruses, can be deadly for the Martians. And even more risky is sexual contact, during which the exchange of microbes is very intensive. Such circumstances can further enhance the genetic isolation of the inhabitants of neighboring planets from each other.
Finally, one more characteristic feature of the “race of the Martians” may be general myopia. It is known that too long stay in closed rooms, lack of a far and wide view leads to visual impairment. But it is precisely such conditions that await people on the Red Planet - in isolated protected shelters they will have to spend almost their entire life, coming to the surface only to carry out certain work.
Further - everywhere
Scientists of past eras believed that progress freed man from the pressures of biological evolution and selection. However, today we know that this is not the case. Modern people continue to adapt to the challenges of the modern world. Mastering new niches of habitation, new sources of food, we are forced to adapt again and again. Statistics show that over the past couple of tens of thousands of years, human evolution has even accelerated. It will accelerate even more on other celestial bodies.
Even on Earth, babies are born with an average of about 60 new random mutations. The increased radiation from Mars will necessarily increase this number, providing an additional rate of change. Scott Solomon believes that one should not rely on her either, suggesting that the preparation of the future "race of Martians" be started artificially in advance. Use genetic engineering to enhance the production of protective pigments, strengthen the skeleton, etc. "Is it worth waiting for random mutations if we ourselves can make the necessary changes?" the scientist asks.
His enthusiasm and openness to human genetic modification are not shared by everyone. However, it must be admitted that the very dispersal of mankind in other celestial bodies inevitably stimulates evolutionary radiation and sooner or later will lead to the emergence of new human "races" and species. “There are only two paths before us,” Elon Musk said on this occasion. - The first is to stay on Earth and sooner or later die out as a result of some catastrophic event. The alternative is to become a full-fledged space civilization, an interplanetary species."
Roman Fishman