> Well, when continental species get introduced to islands, it's sayonara
> locals 9 times out of 10, and sometimes very quickly. Earth has an
> enormous biosphere and bacteria at least swap genes with avidity.
> I doubt Europa can match that, assuming it has any life at all, simply
> as there's far less usable energy there.
But with the islands case, you have some species adapted to a
specific niche where there are no competitors and the incoming
species are those from the larger continents where they have
had to compete and survive. They generally come in with
better "genes" and that is why they win.
The proper comparison given your example is species coming into
an island just after it has been formed when there is no established
ecosystem to take advantage of. In that situation the "mainlanders"
don't have an easy time of it. Only a very limited set of species
that have evolved to deal with the resource poor conditions manage
to make a go of it.
Given the low energy availability you cite on Europa, the species
from Earth that would manage to compete effectively are probably
few and far between. The scientific insights that could
be derived from any species that were discovered growing in
such an environment would likely be very great. Nothing like
a few billion years of evolution under really poor conditions
to make you tougher than steel...
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:59:40 MDT