Here's a wildly unexpected proposal that just popped into my brain: Humanity should intentionally contaminate Mars with Earth lifeforms -- as soon as possible! The benefits vastly outweigh any concerns to the contrary. Indeed, it may be the smartest thing our species ever does.
The first obvious benefit is that it will get Earth life off of Earth, making it more likely that it will survive. Humans are wrecking Earth -- but even if we don't Nature may do it for us. All it would take is one big comet or meteor impact -- or a supervolcano or ice-age and much of the living systems and civilization we currently take for granted would vanish in the blink of an eye. Our only insurance is to have a "planetary backup" -- so why not use Mars? We back up our data -- why not our DNA -- why not also backup the amazing ecosystems and living organisms that have evolved so painstakingly over aeons on Earth? By moving at least some of them to Mars we can at least rest assured that no matter what happens on Earth, life in our solar system will continue in other places. But that's just the beginning.
Another benefit of seeding Earth life on Mars is that we can jumpstart evolution on Mars by several million (or billion) years by seeding it with life from Earth. And then we can study how it evolves and adapts. Remember, many organisms contain in their DNA bits and pieces of lots of previous generations and species -- and as they adapt on Mars they could even eventually re-evolve lifeforms we have (or had) on Earth. Perhaps life on Mars will revert to adaptations that existing on Earth when our climate was harsher. But over time that could slowly transform the Mars climate, enabling life to catch up again, and evolve to "higher" forms. Eventually that could even create and spread living systems and ecosystems that humans can live off of, or live within at least. Yes it could take a very long time to evolve higher lifeforms on Mars if we start by just sending microorganisms, insects, landcrabs, lizards, etc, but it could happen given that the selective pressures on Mars are similar to those on Earth. On the other hand, life could go in a completely unanticipated direction -- that would be interesting too!
It's actually a fascinating and important scientific question worthy of funding and long-term study: given the same precursor lifeforms and similar or identical conditions, will life evolve along the same evolutionary course as it has on Earth? Will Mars get dinosaurs eventually, or even primates? And what about flora and fauna? If the Bush Administration wanted to propose A Really Bold Initiative what could be better than seeding life on another planet?
Hey NASA, are you listening? -- this idea is worth $100 billion in funding. We could learn more from seeding life on Mars and studying it as it adapts, spreads and evolves for the next several thousand years than almost anything else we could do with the space program. It will help us learn about ourselves, the cosmos, and ultimately about how species move to new worlds. It will even lay the groundwork for humans to eventually colonize Mars by starting to build a food-chain and life support web there. And seeding life on Mars would have a greater long-term benefit on humanity, and the solar system, than just about any other space or Earth-sciences research program we could embark on.
The Mars environment may or may not (still) harbor life -- we don't know yet. But one thing we do know: There are many forms of life on Earth that could potentially survive in the harsh Mars climate. What if we started sending drones to Mars, designed to fall to the surface and release their living contents (or even scatter seeds and spray spores, bacteria, viruses, protozoans, etc. from the upper atmosphere?). How about nitrogen fixing bacteria, for example?
How about even sending up installments of desert lifeforms, arctic lifeforms, high plateau lifeforms, etc.? We could easily keep them alive for the trip to Mars by cooling them and slowing their metabolisms, or by sending them in mini ecospheres in which they can reproduce if necessary so that even if the first lifeforms can't survive the trip, their offspring can. We could actually send self-contained eco-bubbles with all the ingredients of mini-self-sustaining ecosystems in them. These eco-bubbles would be designed to fall to the surface and then break open, releasing their contents locally, or even injecting them into the soil. Or perhaps they would fall to the surface and only partially break open -- enabling their contents to live in a warmer, protected habitat and gradually spread and adapt to survive near the edges and eventually outside and beyond.
This would plant little ecosystem colonies all over the surface of the more habitable parts of Mars. There are lots of good reasons to do this. First of all, it would get higher lifeforms onto at least one other planet -- in case something terrible happens here on Earth. Who knows -- if we are the only place with life (which I doubt) at least we will have protected life by spreading to one more planet.
Here's an intriguing speculation: Perhaps the threshold that species must cross to become truly advanced is the moment when they first spread life intentionally to another world. At that point they become Creators rather than just a Creation. Perhaps long ago that's how life started on Earth. Perhaps that's how life is really propagated across the universe -- sort of like social networking but on an evolutionary and interplanetary billion-year scale.
This really could be a pivotal stage of evolution -- and we are arriving there now -- we have the ability to intentionally seed life on another world today. We just have to decide to do it; Then we graduate. Maybe the height of terrestrial evolution is when a species reaches the point of starting, and managing, evolution on another world. That's when it enters the process of evolving to the next level of scale (in space and time) -- from a "terrestrial species" to a "solar species."
In any case -- Mars awaits us! A whole new world with untold hidden resources and opportunities for humanity. Because of this potential, humanity will seed life there, one way or another -- perhaps by accident or perhaps intentionally. In any event, however it happens, a major benefit of seeding Mars as soon as possible is that it will speed up the transformation and terraforming of Mars' climate -- bringing us humans that much closer to someday being able to live there.
For humans (and many other mammals) to live on Mars, we need to make Mars hotter and we need to transform the atmospheric gas ratios -- and that means we need to add heat-trapping gasses to the atmosphere. We also need to change the balance of gasses in the atmosphere by introducing the right organisms onto the planet to process the existing atmosphere, or release gasses that are trapped in the soil and minerals etc.
Life is great at transforming worlds. Just look at what's happening on Earth! The more living things we can send to Mars the better. If we're smart we will do it in logical order -- introducing a chain of species, each one helping to transform the environment to support the next one. And the sooner we do it the better. I know the purists here on Earth will object to this proposal -- they will appeal to The Prime Directive; they will appeal to scientific ethics; they will appeal even to religion -- they will want to keep Mars as it is and not change it. But that's impossible -- if humans continue to probe Mars we will contaminate it eventually.
LIFE IS CONTAGIOUS. It's a transmittable disease that infects planets wherever it goes. It is impossible for humans to not eventually infect Mars with life (unless we destroy ourselves before we can send manned missions to Mars). Once manned missions go to Mars, life on Mars will be a reality. At first it will be temporary -- in the form of manned colonies -- and eventually it will be permanent and will "break out of the bubble" and start spreading on its own. It's unstoppable -- so therefore at least let's do it right!
We need to move Earth life -- and ultimately our own species -- to other worlds as soon as possible -- it's our best hope for long-term survival and evolution. Until we are no longer stuck in a single ecological niche we are at great risk as a species. And not just us, but all life on Earth. The more we spread, the more likely we survive and evolve into the distant eons ahead. But that's just one reason we should do this. The other reasons are equally compelling: We can learn, explore, and evolve ourselves, our civilization and technologies. Eventually we may even reach the stars. It all starts by seeding life on Mars.