Seems the home-grown risks are more under our control but insurance still not a bad idea. I see that a lot of Florida home owners can no longer get hurricane insurance. The possibility of tipping the greenhouse effect into irreversible runaway seems the most probable of disasters and Stephen’s right to alert us - the scientists who are actually doing research in the climate area are freaked, but have to be calm and reasonable and not overplay the worst case scenarios. I expect to be made seriously uncomfortable by global warming - won’t be a nice disaster I can watch on TV - I, and most of us are going to be directly affected - scarey!

Why is the human species worth preserving? Well as of right now we are the only known sentient technological species that we are aware of. For better or worse only we would stand a ghost of a chance to both detect and to redirect the rock.

In order to colonize another world one of two things would have to be done. Either we would have to change the world so that it would support our current form of life or we would have to change our form of life so that the new world could support it. (I’ve always been a big fan of terraforming Venus personally, but that may just be me.) With advances in genetics perhaps changing our current form of life might be the easier of those two options.

On optimistic days I would say that humans working together can do anything that it is possible to do. Including colonizing other worlds.

On pessimistic days I picture the last two men, waist deep in an ocean of raw sewage, locked in a life or death struggle over the last bit of edible food.

Whichever of these visions is closer to the truth it’s likely that I won’t be there for the finale. Unless we get hit by the rock of course. That could happen anytime.

That is partly another question, since we were loking at survivability. However, I think organisms may easily loose some tools in the tool box. Not many though. Look at the Hox box - those genes that decides the body structure have been kept after their inception.

“Let me pose a question: What collection of traits would you be willing to sacrifice in order to enhance your survivability outside the Biosphere/Geosphere of planet Earth? Moreover, how far would you be willing to delete your traits - at the same time - sacrificing quality of life before deciding that life is no longer worth living?”

This is your idea, not mine. I observed that evolution doesn’t stop, so we will change both on Earth and in any colonies. Our descendants will be adapted (or die) to live harmoniously with whatever “nature” surrounds them. If that will be a much poorer life they will compare with history and think they were shortchanged. They will however find life worth living - all living creatures do.

Seriously, I find this line of comments as a flailing with unprobable outcomes.

According to your link, a species will delete specific traits in order to improve its overall survivability to a particular environment in question. However, if a species has to drastically reduce its traits in order to survive in a highly sub-optimum, hostile environment, this species - in the process of “trait-downsizing” - is at extreme risk for significantly losing key features to its quality of life. Let me pose a question: What collection of traits would you be willing to sacrifice in order to enhance your survivability outside the Biosphere/Geosphere of planet Earth? Moreover, how far would you be willing to delete your traits - at the same time - sacrificing quality of life before deciding that life is no longer worth living?

The evolution argument is also wrong. It is a common misconception. Evolution has no inherent direction. Selection for fitness can mean simplifying both genotype and phenotype. ( http://www.talkorigins.org/indexcc/CB/CB932.html ).

You are looking at short term budgetary concerns. NASA would probably be much smaller without the manned part.