The fossil record shows that evolution has
not progressed uniformly. From time to time
short duration events caused mass extinctions.
The usual explanation consists of postulating
catastrophic events such as collisions of large
bodies with the earth causing disruptions of
the weather pattern, or astronomical events such
as a supernova explosion in the vicinity of our
solar system. Large volcanic eruptions, earthquakes
and the appearance of certain predators as well
as other causes may also have caused some extinctions.

There is however one possible cause that to my
knowledge has been totally ignored. It can be
hypothesized that the introduction of life forms
from outside our solar system may have disrupted
ecological balance. Such introduction could have
come from meteors (think Tunguska) that may have
originated from outside our solar system, or from
visitations alien intelligence explorers.

If such alien biological entities were to be detected,
the wrong way to treat them would be a secret quarantine.
The world would never become aware of the threat and
would be unable to cope with it. On the other hand
releasing such information to the public would allow
the scientific community to diagnose any problems
and to develop countermeasures it these object turned
out to be threats.

I suggest that our legislators consider passing
laws that would make it illegal (criminal) to suppress
any and all biological information dealing with alien
forms.