Philip Witham writes:
> Yes, but the premise of the discussion, here, is that the Earth is
> becoming immanently uninhabitable (post assembler) in who knows
> how many ways, else why leave in such a rush? So: given not much
> choice, would you bet that we can't figure it out? With Advanced
> nanotech to pry into the minuscule eco-details and also to manipulate
I don't think we should wait around for advanced nanotech before we start trying to understand our biosphere and how to replicate it. I'm puzzled and frustrated that so few biosphere closures have been funded so far. If we take the defeatist attitude that the Earth will be uninhabitable soon regardless of what actions we take to try to prevent this outcome (which is not my inclination), then we certainly ought to be trying to understand the "proven technology", as Crocker puts it, that has sustained us so far. We have zero experience in maintaining viable societies over the long term in space, just as we have zero experience in reanimation from cryostasis or mind uploading. It would be foolish to destroy (or fail to study) our current life support systems before their replacements have been developed and *tested*.
Also, in re Bradbury's objections to Crocker's biological traditionalism, the human genome was not designed, and it was certainly not designed with any goals of readability or maintainability in mind. It is growing clearer that our genome is completely riddled with every computer programmer's nightmare: multifunction code passages. Tweak this neurotransmitter which has this benevolent effect, and you will find that the tweak also causes two or three malignant changes in function, as well as four or five neutral ones and perhaps one other unexpected improvement. No matter how well we understand gene expression and ontogeny, the multipurpose use of most of the sophisticated molecules in our body will make tweaking the design extremely difficult for human engineers. Granted, machine assistance may make the problems tractable, but I think its too soon to make specific confident predictions about the ultimate capabilities of human genetic engineering and how soon we will be able to migrate ourselves out of the local optimum of human function into some better, but posthuman, design. If you think the planet will become uninhabitable very soon, then we need to start figuring out how to make primate societies and the biospheres that support them viable in space. We may not be able to change ourselves as fast as we would like.