Terraforming: what Earth life forms are needed to support human civilization?

Suppose you have just terraformed a formerly lifeless planet. You’ve added enough microbes, algae, and whatnot to get yield an Earth-like atmosphere and fertile soils. You now want to make it possible for humans to live permanently on this world, without needing to receive any supplies from elsewhere.

What additional Earth life forms will you have to introduce? Obviously some agricultural crops, plus flying insects to pollinate them. Are any other life forms really needed? Any sea life? Any mammals of any kind besides humans? Can you get away with importing just a few key organisms, or will you end up having to copy the whole ecosystem?

Barley, hops, yeast

Some kind of trees for lumber.

I don’t see a way around importing a whole ecosystem, though that might depend somewhat on how much artificial effort you’re willing to expend.

For example, you say that you’d insects to pollinate the plants, but pollination could be taken care of manually by humans or robots.

Earth farms subsisted for millennia largely thanks to manure produced by animals like horses and cows, but you could manufacture artificial fertilizer instead.

Earthworms are an important species for aerating soil, processing nutrients, etc. But if you’re willing to use extra fertilizer and mechanical aeration, you can probably do without them.

Many species have a role in digesting or decomposing cellulose from dead plant material. Without them, it’d build up out of control until people came in and burned it or something.

So… if all you want is something like a hydroponic garden that is totally dependent on mechanical support, you won’t need to import much of anything. Maybe some single-celled critters.

If you want anything like a self-sustaining environment, then I think you need to import a whole ecosystem.

Also… I suspect that anything you do import will have a tendency to escape and go native. Do you want them randomly evolving to fill empty ecological niches, or would it be preferable to fill those niches with known species?

I read somewhere that earthworms did not exist in North America prior to the European colonization. The native people did manage to do some agriculture without them. But they would definitely help. Although one wonders whether, without predators or parasites, they might grow to gigantic proportions … :eek:

You bring up an interesting question: will it be possible for this world to support enough industry to maintain a high level of technology? There will be no fossils, and therefore no fossil fuels. How will they fire the furnaces to forge metal parts to repair their machines? Of course, since this is the science-fiction future, you can posit that some more advanced energy source has been developed.

The random evolution to fill empty niches would probably be fast by evolutionary standards, but would still take ages to occur from a human point of view. Except for microbes. Those evolve extremely fast.

Pigs. Bacon, ham, pork chops, spare ribs… Plus they eat anything. My terraformed planet is gonna have pigs on it.

Perhaps some varieties were introduced, but I think the Oregon and Palouse earthworms are native to the Pacific NW… and also happen to be giants, getting three feet long and an inch in diameter.

Terraforming is certainly harder than getting energy from renewable sources. Anything that provides electricity will run a forge. Nuclear, solar, wind, etc.

Yeah, I agree. Terraforming is already a project that takes ages to occur from a human point of view, so it seems worth thinking about. Global warming is probably the most rapid terraforming project possible at virtually any technology level, and it’s going to take decades to change the temperature a handful of degrees. If we’re trying something more ambitious like making Mars habitable, we’ll need much bigger changes than that, probably over much longer time frames. And once you’ve invested all that effort to start living there, it would be foolish not to plan at least a few thousand years into the future. If you let one family of mice loose into a world empty of competition and predators… look out!

I don’t think this is correct; according to this list several families seem to be indigenous to the Americas.

Insects might be optional; there are plenty of wind pollinated crops (wheat, maize) and trees.

No mosquitos!!

It might not take anywhere close to the complexity that people might make it out to be. All you might need are several strains of genetically engineered algae that make everything human beings need to eat.

You don’t *need *trees or crops or land animals or insects or any of that. Just the right microbial stew (there’s a lot of microbes that live symbiotically with humans) and something to eat.

In any case, by the time such a scenario ever occurred, I think humanity would be at the “design biological organisms for fun” stage of technology. I think we’d be able to actually just print off a few billion species and make an Earth II, and change the species on a whim if problems are encountered or if we want them all to have different fur color or different sounding mating cries.

Nah, they suck.

I imagine that your chances of being able to deliberately create a functional, stable ecosystem, de novo, with the specific species you choose and none other, are pretty much nil. Ecosystems are too complex, and we don’t understand them enough. Consider the experience of Biosphere 2 which was attempting a much less tricky task - simply replicating some existing Earth environments in a closed system. The first experiment lasted two years, but:

Or consider how often even just one introduced species in a new environment has gone completely nuts and overwhelmed the local ecosystem.

With our current level of knowledge, I should think that the only serious terraforming option open to us would be to throw a whole bunch of species at the planet and settle down to watch the resulting decades or centuries of evolution as some die off, some overwhelm the environment, and slowly some new ones start to evolve to fill gaps we didn’t even know were there.

You need bacteria up the wazoo, but it would be really hard to decide in advance which ones to bring.

I see what you did there (the bacteria modern science knows that humans need to stay alive are in our gut and colon)

I remember some book which devoted an entire chapter to Bio-Dome and its failure. The biggest problem, apparently, was that the designers “knew” more than the experts, so they screwed up in interesting ways. The excess CO2 for example, was because they thought if the calculated amount of compost topsoil was good, ten times as much would be better. This produced ten times as much CO2 as expected. Worse than the atmosphere imbalance, the high CO2 levels also caused deterioration of the concrete walls making it a risk the structure could fail.

They planted too many of the wrong kind of crops, causing an explosion in pest insects; the occupants then had to spend their waking hours removing insects from crops by hand, and still almost starved. Medical monitoring found dangerous levels of PCB’s in their blood - they starved so badly their accumulated fat was used up, releasing a lifetime of accumulated toxins that are typically stored in fat cells.


I also recall an article in Scientific American many moons ago, about the problem of dung beetles in Australia - or more specifically, the lack. Everywhere else, ruminants have beetles who “take care” of the cowpats they leave behind. Australia had no such insects, and instead huge tracts of grazing land were in danger of being paved over by accumulations of sun-dried rock-hard cow pats, aided by the excessively dry climate. There are plenty of other eco-imbalances to be found. Australia is famous for its rabbits. Cats and rats introduced by sailors have devastated a number of islands where the local animals have not evolved a defence. There’s one theory that says rats accompanying the Polynesian settlers, not competition for log rollers for statues, destroyed the forests of Easter Island; the rats ate most of the nuts that fell, removing the forest’s ability to regenerate.

So no rats…

However, I would suggest the Darwin’s Finch approach. Horses don’t morph into tigers. To have an ecosystem self-adapt, it needs “starter kits”. Give it some small, simple, basic, do-all animals like plain sparrows and field mice and let them over time evolve to fill any missing niches. …Which is a great concept, until you have to fight the mice devastating your crops. But then, that applies to any smaller herbivore. They’re going to eat where the herbi- stuff is.

For food animals, perhaps the goat is a good choice. Feral pigs can grow to be dangerous. Cows are too big and take up too much resources. Sheep cannot survive easily without humans shearing them, Chickens might be OK, but then they’re likely toast as soon as you release a predator.

Also, if you’ve created an entire world, you mostly want to seed a non-domesticated animals to create an ecosystem. That means a wide variety of “starter” animals. They have to be introduced in stages. The forest needs to be there before the birds, the grass before the deer or goats. Fruit trees would be nice, but they tend to flower and need insect pollination. (You cannot pollinate an entire world by hand). The trees you pick have to be able to spread their seeds; so does the grass, otherwise all you get is wall-to-wall dandelions. Maple trees have those winged seeds. Oaks rely on squirrels to grab their nuts. Blackberries are spread mainly by birds and small animals, IIRC - but enough fall nearby that untamed blackberries can generate incredibly spread-out thick bushes.

For fast, practical wood - I would suggest bamboo, the stable framing material for huts across the far east tropics.

But then, we haven’t talked about soil. There are marginal plants, lichens, and similar organisms that will grow with a minimal amount of real soil, then eventually build up to decay and produce real soil for the next generation. From what I understand, the fossil fuel of this generation is the result of buried detritus of past eons. Much of that burial happened before the evolution of grasses, when widespread mudslides and heavy silt deposits were much more common. A lot of rich eco-action happens in tidal pools and especially deltas, where the washed-down organic matter from an entire river basin concentrates in a delta, with plenty of water to sustain life too.

We also haven’t discussed the ocean ecology. There’s plankton and algae, which get their nutrients from the ocean and become a food source for higher animals. I would suggest starter animals again, some smaller fast-reproducing fish that can eat the plankton, and something like minnows for fresh water. Given abundant food sources and fast reproduction cycles, expect them to diverge into species that can accommodate every niche.

Again, there’s the question of whether and how to introduce a predator species. Without one, you risk a boom and crash of the prey species. With it, you risk the same thing happening to the predator species. My understanding is that the most important thing is that the prey recognize the predator and be evolved against them. Many of the ecological crashes were for lack of defence. Moas and dodos were not designed to escape humans, even if they had recognized them as dangerous. Seabirds nesting on small rocky islands had no time to learn or opportunity to hide their nests and chicks from introduced rats. Small fish can hide from larger ones in reeds and seaweed. Rabbits outrun wolves, burrow to escape owls etc. (There’s another problem - burrowing animals need soil that can be burrowed)

Fortunately, with a huge world, you can experiment on various islands to see what works or not, before turning that animal loose on the mainland. But never forget, too, how many thousands of different ecosystems there are in one world. An animal adapted for one climate or landscape will not necessarily do well in another.

You can do a small scale experiment yourself…

You’re going to need something to fix nitrogen.

From the op: “You’ve added enough microbes, algae, and whatnot to get yield an Earth-like atmosphere and fertile soils.”

Surprisingly tricky proposal. Male mosquitoes do not suck, and then…

http://www.esa.org/ecoservices/poll/body.poll.scie.arep.html

If no mosquitoes means no peat bog orchids, I think that’s a price we’re willing to pay.