Great Filter
<p>Apr 24, 2010 4:32 PM
 
Robin Hanson  GREAT FILTER
 
civs  self-destruct.
 
The main counter-intuitive conclusion of this observation is that t<b>he easier it was for life to evolve to our stage, the bleaker our future chances probably are</b>.
 
Hanson's list, while incomplete, describes the following nine steps in an "evolutionary path" that results in the colonization of the observable universe:
The right star system (including organics & potentially habitable planets)
Reproductive molecules (e.g. RNA)
Simple (prokaryotic) single-cell life
Complex (archaeatic & eukaryotic) single-cell life
Sexual reproduction
Multi-cell life<b>
Tool-using animals with big brains
Where we are now
Colonization explosion</b>
According to the Great Filter hypothesis at least one of these steps - if the list were complete - must be improbable.</p>