Once we establish human colony on Mars, we'll be facing some serious health issues.
People will suffer a loss of bone density due to low gravity, reduced aerobic capacity, decreased muscle mass.. the list goes on..
But why can't our bodies adapt to lower gravity, and how can micro-gravity damage our eye sight?
To find answers to those questions we have to ask the creator of human body, Evolution.
So Evolution, why do we loose bone density in lower gravity?
-- I don't know
But how can you not know, you created us?
-- Yes I did, I created you by mistake
How do you mean by mistake?!
-- Actually you are a result of accumulated mistakes I made in past, but they turned out to work well together
Why do you make so many mistakes?
-- That's how I find brilliant but totally unexpected solutions
How do you know you found a solution by mistake?
-- You survived
So you make a mistake, and wait to see if I'm gonna survive?!
-- Yes, indeed, your are starting to get it!
Ok, now I see, you don't really care about us...
-- Should I?
You didn't answered my question about bone density in low gravity environment?
-- So you ask me if I could have created your bones better so that they work well in low gravity?
Yes, you are finally cooperating!
-- No I couldn't, because my design studio is Earth, and everything I create works well only on Earth
But why can't you do better so that it works on Mars too?
-- Because I can't take you to Mars to see if you can survive, but once you get there by yourself I can help with that. But don't expect too much at first, It'll take me some time ;)
Ok, take your time evolution, I'll wait!
-- No, I'm talking about much more time, something like few thousand maybe even hundred thousand years before you humans notice any difference in how you live under Martian conditions.
This is not what I was expecting to hear :( That's really a lot of time!
-- Yes, a lot. You humans usually overlook the importance of time.
Ok, let's make some conclusions from this conversation. We humans will continue evolving once we get on Mars, and at some point we will adapt to Martian environment, but it'll take thousands of years before we can see any noticeable results of evolution on our bodies?
-- Maybe, maybe not. Depends. I like to select those that don't fit, they simply get removed from population. This is how I work. But your technology and medicine will make this process harder for me, and harder for you in the long run!
So you say, we shouldn't help ourselves once we get there, we shouldn't use medications, we shouldn't simulate higher gravity and so on?
-- No, but in either case, human life on Mars is not going to be enjoyable. People will struggle to survive in those conditions no matter what, you are simply not designed for that environment. Maybe due to high radiation levels, even I wouldn't be able to function as efficient as I do here on Earth.
Huh, that's not a bright future for humans on Mars!
-- For humans probably not, but is it about humans or something else?
Of course it's about humans, we as a specie will ensure our survival by becoming multi-planetary civilization!
-- I would agree and disagree at the same time. Life from Earth will span across multiple planets and eventually other solar systems and galaxies, but biological humans I made here on Earth will not be those colonists. You will have to improve on my work using advanced technology, and eventually merge with that technology to become something new. Only that way you will truly be able to leave this environment and colonize the entire universe.
It is only logical that with your current propulsion systems Mars is considered an option for human proliferation. Once you develop sub space propulsion you will find much better destinations present themselves.
In time Mars will become more like a hub or stepping stone to lon range destinations, rather than a destination in itself. There are some incredible planets hiding out there!