Terraforming - Species Transport

[Kryten]

I'm actually curious about this, and I have only glancing knowledge about biology. I'm probably using terminology wrong when I say 'sterile'. I guess I'm referring to environments with a lack of non-biologically occurring organic molecules. Could autotrophic terrestrial bacteria survive on Mars? Or on a sterile Earth-like planet with a nitrogen-CO2 atmosphere?

Certainly yes for the second, but I'm not sure about Mars. You'd need something that's an autotroph; capable of fixing nitrogen, surviving low temperatures, low pressures, strong oxidising agents (peroxide), and high levels of UV, all at once. You could bypass some of these by having chemotrophs underground instead of phototrophs at the surface, but then there's no obvious nitrogen source.

Edited October 9, 2014 by Kryten

[KerikBalm]

While not all bacteria can fix carbon, if you were to take a scoop of dirt or water from pretty much anywhere on earth, and put it on this sterile world of yours with similar conditions in terms of water, temperature, light, elemental composition... something in there would grow.

It could be even easier if underground there were sources of ethane and ammonia.

Certainly, earth has complex ecosystems, and even amoung the bacteria and Archea, few are truly at the base, and rely on other organisms to produce certain things.

But of course, there are thos at the base, that do everything from scratch.

I wonder about a plant that can fix nitrogen (such as with nodules supporting symbiotic bacteria) - it should be able to start growing right away if planted on such a world.... but plants have evolved to live in an oxygen atmosphere (that their precursors helped to create). They store sugars and have mitochondria, and consume oxygen at night, and during germination from a seed.

Sure, they can just do glyocolysis... but how well would they survive the initial absence of free oxygen in the atmosphere...

Cyanobacteria would be great first colonists:

They can fix both carbon and nitrogen.

Or you could go down to a black smoker, and take some bacteria from there, and find a volcanic vent on your new world... but I think cyanobacteria would be a better bet for quick terraforming.

As to an alien biochemistry... I'd think that generally the products would be mutually exlcusive in use, and it would come down to what the "superior biochemistry" is - although the already entrenched one may be stable enough that even if ours was "superior", it would loose (whereas it may win if you take a sample of the alien biology, a sample representitive of earth life, and then stick them both at opposite ends of a sterile world, and see which one wins in the end... or if a stable balance is reached... it would be a cool experiment)