How humans on Earth could be banned from visiting Mars in the future. There’s a real possibility that if we’re successful in being able to establish a long-term colony on Mars, that it could actually lead us down a path where a new human species evolves on Mars.
And the reason is that, as far as we understand new species evolve most commonly when populations become isolated from one another, and those populations aren’t able to come together, mate, and produce offspring.
Those people that are living on Mars will be able to adapt to the conditions on Mars which are very different from the conditions on Earth. So, that could lead to a situation, where people who are living on Mars are actually evolving in a way that is different from the way humans are evolving back on Earth.
And what’s more – because there’s no microbial life on Mars, as far as we know, there’s a possibility that we could actually start to eliminate infectious diseases causes by microorganisms among people living on Mars.
The only microbes that would be there would be the ones that we take with us. So, if we take precautions to not introduce microorganisms to Mars, especially those that cause disease, and if we make a decision to not bring animals that are reservoirs of disease, then we might be able to avoid additional infections, new infections, in the future.
So, if you have people living on mars that evolve to the point where they lose their immune system or it becomes less effective, it could make it really dangerous for people coming from Earth to Mars because they might accidentally introduce a new disease.
So, that leads us to a situation where you have people living on Mars and people living on Earth, and they don’t interact with one another because of the fear of starting an epidemic on Mars. In that situation, it would be very likely that people living on Mars actually evolve independently and could eventually become a new species.