Re: [SG,DS, Colonial] Invasive Species

On Thu, 4 Feb 1999, Izenberg, Noam wrote:

> Can you believe I've got something _else_ to say re: DS and SG? I
can't.

it must be a trick. he's not the real iceberg!

> Human colonists/livestock, etc. are Invasive species in most any
> pristine planetary ecosystem.

in my understanding, humans tend to settle on worlds that they have just
terraformed from dead balls of rock and simple organics. this is based
on
the assumption that planets in the habitable zone with life are
relatively 
rare, an assumption for which i have precisely zero evidence. if this is
the case, then the only ecosystem around when humans land will
be the one they set up.

i should think that trying to live on a world with another competing
biology would be very, very hard. it would be better adapted for local
conditions, making it really tough for imported bio to get a grip. even
scorhed-earth slash-and-burn policies would have a hard time clearing
the
way of native life.

> Surely some ecosystems have similar
> policies as the new US policy.

ecosystems do not have policies, because ecosystems do not have
intelligence and free will in the same way as human governments.

anyway, to imagine hordes of big things making direct attacks on the
invaders is to completely miss the point about biological warfare. a
sentient ecosystem would respond by sending microorganisms to bring
disease the humans and their crops, to alter the soil they use to make
it
worthless, to pollute their water supplies, corrode their metal, devour
their plastics, and so on.

> What would a SG/DS scenario where the
> planet's indigenous life seeks to evict the newcomers look like?

pretty boring - "okay, where are the targets? what do you mean, there
are
no targets?", "sarge, i feel ill ...", "me too ...", etc.

> Enemy
> units would not be military per se, but anything from insect swarms to
> killer plants, to Armored Elephantine Behemoths.

very sf, but with a high f component and low s. why would these killer
plants exist before the humans arrive? nature is unlikely to produce 
defences against a threat which has not yet arrived - this would require
speculation and forethough, qualities which nature does not possess.
unless we're talking planetary hive-mind here.

> Human agriculture is almost definitely going to be "invasive" to new
> ecosystems. Part of the  challenge of colonial survival is making sure
> you can sustain your food.

the clever option is the judo way - adapt the colonists to eat the local
organisms. engineer symbiotic bacteria for the gut which will break down
the alien molecules and rearrange them into forms humans can use.

> Another thought about the Class M stars is
> that the sunlight will be UV poor for green growing things.

chlorophyll doesn't absorb light much below 400 nm wavelength; uv light
is
stuff below about 350, i think.

> Perhaps a
> different take on the modulation of sunlight is what's really needed.
> Instead of Satellites illuminating cities, we need full spectrum
> 'stadium lights' illuminating terrestrial crops during the daytime.

in which case it is probably cheaper just to grow things in hydroponic
farms with artificial light.

> Or engineered crops that can thrive under the new world's conditions.

much, much cheaper!

On Fri, 5 Feb 1999, Robert Crawford wrote:

> On Fri, Feb 05, 1999 at 12:18:43PM +1300, Andrew & Alex wrote:
>
> >	Actually, I was under the impression that anything that grows
_doesn't_
> > need UV light. Which is why humans have melanin and why we burn
under
> > sunlight with UV in it. UV light tends to sterilise and destroy
organic
> > molecules, like DNA and so on. Remember the hole in the ozone layer?
The
> > ozone layer filters out UV light, except where the hole is.
> 
>	Well... the ozone layer doesn't get _all_ UV, and it only
> works in a specific band. Some UV _is_ necessary for plants, and for
> people. Isn't vitamin D formed in skin by UV light?

"Provitamin D is converted to Vitamin D3 by the action of ultraviolet 
light through our skin". uv light is part of the process by which
vitamin
d is made. however, that's not to say it couldn't be done other ways.

>	Too much of a good thing is bad, but having none of it would
> be worse. Planetary colonies in shirt-sleeve climates probably won't
> have any problems, but colonies in pressurized environments will
> probably have lots of flourescent lights to help with the _lack_
> of natural UV.

or just lots of vitamin supplements, or vitamin d in the bread, or
endosymbiotes synthesising it themselves.

Tom