  One of the mainstays of the controversial "rare Earth" hypothesis is the
"Goldilocks problem" regarding various parameters describing a habitable
planet, partially involving the role of mass extinctions and other catastrophic
processes in biological evolution. Usually, this is construed as support for
the uniqueness of the Earth's biosphere and intelligent human life. Here I
argue that this is a misconstrual and that, on the contrary,
observation-selection effects, when applied to catastrophic processes, make it
very difficult for us to discern whether the terrestrial biosphere and
evolutionary processes which created it are exceptional in the Milky Way or
not. In particular, an anthropic overconfidence bias related to the temporal
asymmetry of evolutionary processes appears when we try to straightforwardly
estimate catastrophic risks from the past records on Earth. This agnosticism,
in turn, supports the validity and significance of practical astrobiological
and SETI research.
