Let’s say the future has come and mankind has managed to populate Mars and get comfortable there. What would a Martian colonist look like after thousands of years? Would his appearance be different from that of an earthling?
Scientists say that prolonged residence on the Red Planet, where gravity and sunlight are weaker than on Earth, and radiation is much stronger, will lead to rapid evolutionary changes. Experts even believe that Martians can turn into a new kind.
“Two populations of the same species, settled in different isolated territories, begin to differ from each other – remember the Galapagos finches studied by Charles Darwin. The finches living on one island are different from the finches on the other island: in different territories they have signs that help to survive in the very environment where they settled, Biologist Scott Solomon writes
in his book Future Humans: Inside the Science of Our Continuing Evolution. – If speciation on Earth’s islands takes thousands of years, then on Mars this process will go much faster due to the huge difference in conditions. In just 100-200 generations, or 6000 years, a new kind of person may appear on the Red Planet.”
The new kind?
Six thousand years is a short time for a person to change beyond recognition. Modern Homo sapiens exist as a separate species for an estimated 160,000 – 45,000 years. And some scholars doubt the words of Solomon.
Biologists Philip Mitterreker of the University of Vienna in Austria, says :
“Speciation is a lengthy process that usually requires reproductive isolation (the inability of members of one population of a species to interbreed with another – Ed.) for millions of years and a large population. Some human groups have been isolated for thousands of years and are still far from becoming a separate species. Therefore, it is unlikely that the people who colonize Mars will last for 6,000 years. On the other hand, conditions on the Red Planet are suitable for minor physical changes to begin to appear among the colonists after a hundred generations.”
For Mars to undergo any evolutionary changes:
1) natural selection should work;
2) the local habitat must be different from the terrestrial. If you create completely terrestrial conditions on the Red Planet: strengthen gravity, put artificial lighting, produce the same food as on Earth, people will not change;
3) differences in conditions should not be too strong so that the population does not die in the first weeks.
How Martians will differ from earthlings
When a person settles on the Red Planet, he will no longer need a heavy, well-mineralized skeleton. The attraction on Mars is much weaker than the Earth, the colonist’s weight here will be almost 3 times less, which means that the load on the skeleton is lower. The need for massive bones will disappear, the body will become unprofitable to spend energy on their content.
“People with heavy bones will spend more calories, energy and minerals to build their skeleton, so on Mars they will “lose” evolutionarily to people with thin bones,” Drobyshevsky notes in the lecture.
The same goes for the digestive tract. In conditions of reduced gravity, a person needs less energy for walking and physical labor, so he will not consume as much food as on Earth. The digestive apparatus will contract, the bodies of the colonists will become narrow.
When the Martian arrives on Earth, people will see a thin man with fragile bones. The weight of a Martian will increase almost 3 times: a 38-kilogram individual on our planet will weigh 100 kilograms, this will cause an additional load on his bones. Most likely, he will not be able to move around without help, he will need a cane or a wheelchair. Another “surprise”: a Martian colonist could injure their chest even with a friend’s “pat in the back”.
A Martian visiting Earth will die after some time from heart failure.
On the Red Planet, in conditions of low gravity, the heart muscle does not need to work so hard and contract quickly to pump blood through the circulatory system, as on Earth. Therefore, the Martian’s heart will become “weaker”, that is, less “trained.” In terrestrial conditions, it simply can not cope with the load.
Mars is much farther from the Sun than Earth. The red planet receives 1.5-2 times less light, because of this the eyes of the colonists can change.
“A sunny day on Mars is like a cloudy day on Earth, – explains Natalie Kabrol, a planetologist at SETI. – Our eyes are accustomed to a certain amount of light. Martians will have to adapt to new conditions: either the brain will develop a new method that allows the retina to perceive and process more of the light that is, or over time, the colonists will have more eyes.”
There is not much sunlight on the Red Planet, but the ultraviolet radiation (UV) subtle Martian atmosphere transmits many times more than the Earth.
On our planet, for UV protection, the skin produces the pigment melanin, or rather, its variety – eumelanin , which acts as a natural sunscreen and gives the skin a brown tint. The more eumelanin in the skin, the better the ultraviolet rays are absorbed, and the darker the skin color becomes.
In his book, Solomon writes that people who have more eumelanin will be better able to withstand extreme ultraviolet radiation on the Red Planet. Therefore, the skin of the Martians will be much darker than anyone on Earth.
In the crowd, an earthman will easily notice a Martian. A guest from another planet will be distinguished by very dark skin, a narrow body, large eyes, and will move on a wheelchair.
Most likely we would see a Martian dressed in a protective suit, since direct contact with the earth’s environment for him could end in disrepair.
So far, scientists believe that there is no microbial life on Mars – pathogenic bacteria and other “creatures harmful to the body.” Therefore, the immune system of the colonists will stop working in the form in which it works for us – it will lose the ability to fight earthly infections. In order not to die, the Martian on Earth will never have to take off his protective suit and eat only sterilized food.
All the information cited in the article is hypothesis based on the tenets of evolutionary biology. It is impossible to know exactly what adjustments nature will be made in the appearance and organism of Martians.
If the colonists really change a lot and differ from earthlings, what will we consider them? Aliens, or just another species?