Re: Sa'Vasku Colours

>no but seriously folks, my thinking is that if a planet has native
life,
>we won't colonise it. not only because it would be hard, but because it
>would involve knackering the local ecosystem - violating an ecological
>prime directive sort of thing

There would be a more practical reason: it seems from current knowledge
that
Life transforms planets at least as much as planets transform life.
Given that a different set of life-forms would have different amino
acids, different
sets of proteins etc it may be the case that Terran life may not be
compatible:
if the two mix, one has Got to Go, if only from massive allergic
reactions,
or clogging up of biochemical reactions with unrecognised and
undegradeable
proteins that block receptors.
Most Biochemistry is just a cross between playing with children's
building blocks
and a real-time version of 3-D tetris where the blocks can change their
shapes
in limited ways anyway. (sorry Beth :-) ) Add a whole new set of blocks
in the
game and things may not work too well.

ANYWAY...

The ecosphere of a planet - things like the pH of the atmosphere, Oxygen
content
and so on depend upon the life forms that are there. Do a wholescale
Xenocide
on an Earthlike Planet and you may quickly find you have a Venuslike
planet
instead. Don't do a wholescale Xenocide, and you may find that
lithophillic
(Rock-dwelling) bacteria and things that lurk in out of the way places
like
Black Smokers may well come back and bite you in the nth generation.  

Summary: The "Do Not Disturb" signs may be not for particularly ethical
"Only
you can prevent Forest Fires" reasons, but more like those found on
Toxic Waste
Dumps. They're more trouble than they're worth to decontaminate, bare
bedrock
would be cheaper to terraform.

Of course with the advances in BioTech that can be expected in the next
200
years, and the fact that the Kra'Vak and Phalons at least are in
competition
with us, this may not be valid, or the validity may be reduced. Or maybe
the
usual way of colonising is to first convert a planet into bare bedrock,
and
then re-seed. A very unfriendly thing to do to a neighbouring species.

The Tuffleyverse doesn't seem to work this way though: the wars are all
relatively
bloodless, the usual method of attack is not to cause all enemy-occupied
stars
to become Novae, nor to bombard all enemy-occupied installations with
cheap
Gigatonne Planetbusters as soon as they're detected. The fact that
small-unit
combats occur a la StarGrunt or even DS2 means that megatonne or larger
nukes
are not the preferred primary weapons.