Human settlers on Mars could evolve rapidly, becoming an entirely new human species. This has been stated by Scott Solomon, evolutionary biologist at Rice University in Texas (USA) and author of the book “Future Humans: Inside the Science of Our Continuous Evolution”, who believes that human beings on Mars would be subject to “founder effect”, a phenomenon in which species that integrate into new environments also adapt rapidly.
The founder effect occurs as a result of a new and small population, which means a genetic bottleneck in which forms and diversity are radically reduced. It is a phenomenon that we can observe in remote areas or distant islands.
“This usually happens to isolated plants and animals on islands. But, while speciation (formation of lineages that produces different species) in an environment such as an island can last for thousands of years, the accelerated rate of mutation on Mars and the strong contrasts between conditions on Mars and Earth will likely accelerate this process, “says Solomon.
The founder effect can lead to the creation of new species, and Solomon argues that the atmosphere of Mars will accelerate that process. In the course of evolution, saying that this process is rapid is relative, since it takes millions of years to create new species but perhaps “only a few hundred generations, perhaps about 6,000 years” are needed for human life on Mars. lead to the development of a new species.
The weak gravity of Mars (it has only 38% of the gravity of Earth) could cause a rapid loss of bone density (a 50% decrease in bone mass in two or three years, according to the endocrinologist at the University of Wisconsin -Madison Michael Holick), which would lead to a higher rate of broken bones among human settlers. In response to this pressure, “after many generations, the Martian colonists would end up with naturally thicker bones than their ancestors , giving them a more robust appearance,” predicts Solomon.
What about radiation?
Mars also has a much higher rate of surface radiation, which can cause disease, but could also speed up evolution by increasing a greater genetic variety. “After 500 days, a person on the surface of Mars would be exposed to a dose of radiation equivalent to six times the maximum annual amount allowed for employees of the US Department of Energy.” As a result, the colonists’ bodies would have increased their production of melanin – which protects against radiation but also darkens the skin – making them darker-skinned than any human being on Earth.
Thus, the weak gravity of Mars, the high radiation and the lack of microbial life, would introduce numerous environmental pressures to which the colonists would have to adapt or die.
If this represents the future scenario for the human species we still have time to find out, but some experts have contradicted these ideas, stating that “speciation is a long-term process that normally requires reproductive isolation for millions of years. Some human populations have been isolated for thousands of years and are still far from being a separate species, so it is unlikely that humans who colonized Mars would have become a separate species, “says Philipp Mitterocker, a theoretical biologist at the University of Vienna. (Austria).
