A professor at Rice University (USA) believes that the colonists will turn into mutants who will no longer be able to closely contact with earthlings.
NASA is set to land humans on Mars in the 2030s to create a permanent Martian colony. Mars colonists will have to adapt to high temperatures and deadly radiation. Scott Solomon, an evolutionary biologist at Rice University, believes the experience could rob the volunteers of many human traits. The scientist reports that the colonists' DNA will mutate very quickly to help them survive in the harsh conditions of Mars. Over time, their skin will gain protection, becoming thicker to withstand additional solar radiation. The bones will also become denser to cope with the low gravity of Mars. Colonists will practically not be exposed to bacteria and viruses living on Earth, which will completely destroy their immune system. According to Professor Solomon,it will take only two generations for the Martian colonists to become mutants.
The rate of evolution depends on the advantage given by the presence of a particular mutation. It is assumed that in order to survive, humans on Mars will pass on mutated genes at a high rate. Moreover, any close contact with people on Earth can be fatal for the Martians. Without an immune system, they will be vulnerable to any disease, especially during sexual intercourse. NASA is supposed to take these factors into account when preparing to land a man on the moon by 2024, before heading to Mars in 2033.