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Dark Worlds & Alien Ecosystems | What Life Needs to Survive

Could life exist without sunlight? In this Entropy Rising episode, we explore chemosynthesis and extreme ecosystems on Europa and other dark worlds. From Earth's hydrothermal vents to Jupiter's icy moon, discover how alien biospheres might work in space where photosynthesis is impossible—and why this matters for finding extraterrestrial life during humanity's age of space exploration.

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1 I mean, harvesting chemical compounds makes

sense, but, being able to pull it from something that's so non-energy

dense as rocks or iron is crazy.

yeah.

It's like the last thing you think of food.

I think rocks as food is just, like, the,

joke 'cause it's like, what could you think of that's less food than rocks?

But those bacteria, it's hold my rock.

I mean, at that point, you're pretty much

saying life could exist anywhere.

welcome to Entropy Rising, A podcast all about science and futurism.

I'm your host, Jacob, and joining me is my wonderful co-host, Lucas.

Lucas, how are you doing today?

I'm good, Jake.

How are you?

Doing well.

ex-excited for this topic.

I think it's gonna be a fun one.

Would you like to do the introduction?

Sure.

So we're going to be talking about, life without photosynthesis, the way

that life could keep itself going and feed itself and produce energy

without that, and, what would be the base of our ecosystem without,

Plants essentially.

Yeah.

And I think this is actually, in my opinion, a really

interesting topic because it isn't just pedantic or arbitrary.

This is actually a situation that we could envision a lot of life in.

I mean, even in our own backyard, we're looking

at planets like Europa, which of course is one of the moons of Jupiter.

It's completely covered in ice, but we speculate there's a liquid ocean below

that ice, And we think that planet's actually fairly geologically active, just

due to the stretching and compressing it does as it orbits around Jupiter.

So there's a potential energy gradient there, but not light, not photosynthesis.

It's too far away from the sun, and the oceans are covered in ice, so there's

no chance for light to enter there.

So an ecosystem on a planet like Europa, for example, would need

to work without photosynthesis.

So this is one of the topics that we're talking about.

I love all the topics we talk about, but this is one that's actually, I think,

fairly important, especially as we look for life in the universe, because

this might be the mechanism by which life in our own solar system operates.

it is interesting to think about how Europa, the way that it is in that

violent gravity well, there's a lot of energy to be harvested there.

And only because we are familiar with photosynthesis because we

get all that active sunlight, and it is probably the most readily

available for life on our planet.

On a planet like Europa, , in Jake's example, that stretching

of everything could cause a lot of energy to be transferred, and there's

nothing taking advantage of it.

So if there was something under the water, it would be free

game for producing, , nutrients.

Yeah, absolutely.

Now, I do kinda wanna set the stage on this episode a little bit too before

we dive into what it will look like, because I think there are some important

notes and caveats with this topic.

For one, I don't think you're going to ever have a situation where a planet

has abundant solar energy like Earth, and life doesn't evolve photosynthesis.

I just don't think that's viable.

The reason being is it looks like photosynthesis has evolved

several different times in Earth, which means that it's not a huge

evolutionary leap to happen.

Also, it's just a monumental source of energy Our planet gets

so much energy from the sun, I don't think you're gonna

have a situation where you have an Earth-like planet and life

doesn't take advantage of the sun.

That's not really what I think we're gonna be talking about or ever really see.

I definitely think it'll be geared more towards planets that would be

kind of outside of that realm.

You know, like you were saying, on planets like

Europa or planets that are pretty much blocked out from the sun or don't

have a sun that's putting off as much sunlight, and it would be more efficient

for them to take those resources from different energy production.

Yeah, I absolutely agree.

So when I was kind of thinking about what types of situations

would we be finding this type of life, an obvious example, of course, is Europa,

and these are gonna be icy moons of gas giants that get a lot of energy

through tidal heating but otherwise don't get a lot of solar radiation,

and that's one class of planets that I definitely foresee this happening.

Another planet I could kind of envision this happening too

is a Venus-like planet that's further away from the sun.

So we know Venus is the hottest planet in our solar system, and of course that's

just due to the greenhouse effect, right?

Like, Mercury's closer to the sun, but Venus

has a hotter average temperature because of all that carbon dioxide and the,

like, really thick atmosphere.

But not a lot of light reaches the actual planetary surface.

So if you had a Venus-like planet and moved it much further away from

the sun, I think you would eventually reach a point where the surface

temperature becomes habitable, but now you have barely any solar

radiation reaching the planet, right?

Like, this planet's potentially gonna

be further away from its star than Mars is from our own.

It's just that really thick atmosphere trapping whatever solar

radiation does make it in that's keeping the planet's surface warm.

So not only do you get less solar radiation because of the distance from

the star, but even if it was closer, you just have such a thick cloud cover.

So maybe you have a situation where you have Venus-like planets

further away from the sun that have the right surface temperature for

liquid water, but not any sunlight.

That's another type of planet I could kind of

envision working like this.

Yeah.

the last one that would come to my mind, and I know that there

has been speculation of what a low-light planet would

look like a red dwarf- Mm-hmm for example.

The plants would be black 'cause they would be darker to absorb more light.

But maybe on planets even like that, they could be overthrown by

perhaps a more efficient, energy type that could be on a planet.

Let's say it's a water planet orbiting around a red dwarf.

Perhaps, , something would completely take over that ecosystem because

it just wouldn't be as efficient as photosynthesis, and maybe there would be

small pockets of things that use it there, but the actual base of all the food chains

would be a different type of production.

Yeah, red dwarfs are also an interesting one because we think that for

planets to exist in a red dwarf, to be in the habitable zone, the issue

is, is that red dwarfs are so small, and relatively speaking,

they're, cooler stars.

So, The habitable zone is actually so

gonna become tidally locked, and that presents an issue because if you have

a tidally locked planet around a red dwarf, which is, again, how close you

need to be to get adequate sunlight to be in that liquid water range,

what ends up happening is that the one side of the planet is absolutely

baked by solar radiation, right?

Mm-hmm.

It's kinda like a Mercury-type situation.

And then the other side, which is facing away from the star, is frigid.

There's no solar energy getting it.

So when we talk about- planets and life around red dwarf stars, and even

in our episode where we talked about this concept, we usually talk about

life living in the equatorial band, uh, that twilight zone, between the

light and the dark side, and we think that would be the habitable area.

But if you start thinking about how life could function without photosynthesis,

You get a lot more opportunities.

For one, there's a potential the planet could be a little further away.

and even if it couldn't, that's fine, because you are also

kind of unlocking a little bit more of that

planet where life could exist, right?

Like, maybe you could have situations where

convection currents from the hot side and the cool side create a larger

band where liquid water can exist- Mm-hmm but never see sunlight.

Yeah.

Or if it's, A water planet, that's

also really interesting.

It would be tricky, because, an issue with planets orbiting red dwarf stars

is atmospheric stripping, but there is some orbital mechanics that can happen.

Maybe a planet moves in toward its star once the star's kinda cooled

down, so that is definitely possible.

And for a planet like that, that would actually be interesting,

'cause you would have much more of that convection current.

Mm-hmm.

So you might actually potentially have a lot of liquid water, and end up

kind of like we were talking about with that,

phase where you have, an ice-capped portion that's safe from the star,

but also doesn't get any sunlight.

Yeah.

Or it would produce incredibly violent currents, dragging that water

around the planet you would see a band, but it would be larger than

what you would think, because those are meshing more and more together.

And you can even have planets, too, that have a lot of energy in other forms,

if you have a planet orbiting a, a star that's emitting a lot of gamma

radiation, that could be an example.

Or maybe you have a star that's actually orbiting a black hole, where there isn't

a lot of visible light, but maybe there is, again, a lot of gamma radiation.

So you don't have the ability for life to really usefully take care of

photosynthesis, but maybe it can work through a different process and actually

harvest that, that radioactivity, which is definitely something we're

gonna be talking about in a bit.

Kind of a spoiler.

Mm-hmm.

yeah, just a little sneak peek.

So I think that's a good setup for the type of planets we can see.

Yeah.

Which is definitely important, 'cause I know I reiterated it, but photosynthesis

It's a very overpowered ability, and There's just no way life

wouldn't take advantage of it.

So we are talking about kinda oddball planets, But definitely, I think,

interesting 'cause it opens up the doors for life in a lot of places

that we might not first consider.

And for me, that's exciting.

I like that.

it really allows for you to sort of broaden those horizons.

A lot of the times we speculate about what the first life could

be on planets, and we always think of plants, but what if it's not?

Yeah, so even on Earth we don't really

know if life formed around geothermal vents first or tidal pools first.

Mm-hmm.

You know, we've, we've done some statistics.

We seem to think that it was probably tidal pools.

That's more likely, but that doesn't mean that the less likely option

didn't just happen anyways, right?

We don't really know, and I don't think we have a lot of evidence

for it one way or another.

So even on Earth, the first life probably wasn't solar powered, and it's very

possible that it expanded from geothermal vents, which is, I think, very fascinating

, And that just shows how possible this is.

Yeah, it definitely does.

If the basis of our life started from something that,

was an alternate form of energy, then why couldn't it happen

on other planets as well?

Which kinda brings us up into, I think, one of the first ways, of course,

that we are gonna talk about how life can exist without solar energy,

it's one of the ways we actually see here on Earth, which is that life

can take advantage of chemosynthesis.

You know, if photosynthesis is the,

process by which you harvest photons from the sun and turn that into energy,

then you can imagine chemosynthesis is the same, but you're taking advantage

of the actual chemical potential energy stored through chemical reactions.

And this is, like I said, something we see on Earth in these undersea,

really deep, hydrothermal vents, where they're taking advantage of these

sulfur compounds, breaking them apart, and then harvesting that energy.

So that's certainly something we could see and, and that's how we speculate

life might exist on Europa.

it would definitely make sense since they have frozen oceans that could be

Very deep there.

These geothermal vents would actually be perfect

because of the tidal pull and the gravitational pull on the planet

stretching and bending it, it would have very,

very active tectonic plates- So that would cause a lot of, pressure to be created

and a lot of release of these sulfur compounds through these geothermal vents.

It could be an entirely sprawling ecosystem under there for all we know,

and that would be the base of their life.

Yeah, absolutely possible, and I think this is gonna be true for

pretty much any ice-capped planet.

This would be likely a large source of energy for those planets.

It's really the only source, and it's not the only way we see

chemosynthesis on Earth, actually.

There are some bacteria that live really deep, like under the surface in the

crust of Earth, they basically eat rocks, which is I also think very fascinating.

And we didn't expect to find life, that deep underneath the crust, but

we have actually found bacteria that, again, work through chemosynthesis

using iron compounds, to live.

So The chemosynthesis could be not just these underwater hydrothermal vents,

but maybe some other places, too.

I actually didn't, I didn't know that.

Yeah, it's really crazy.

They… Yeah, it's absolutely crazy.

I think they found it, there was this, I think it's in Russia, it's this,

like, really deep borehole, it's almost a mile deep, and they

still found bacteria, and it's, it's really hot, too.

I think it's, like, 130 degrees Fahrenheit or

140 degrees Fahrenheit.

and then you've got these extremophiles eating iron

and living in these high temperatures.

It's absolutely- Yeah … crazy that life managed to make that work.

Has to be hot for them to soften up their food a little bit.

Yeah.

My God.

The rocks?

Yeah.

Just some rocks.

what is that, population that you can

play on Stellaris where You are rock people?

I have no idea.

God, it reminds me of those.

I'm trying to think of the name.

It doesn't matter.

That is insane.

I mean, harvesting chemical compounds makes

sense, but, being able to pull it from something that's so non-energy

dense as rocks or iron is crazy.

yeah.

It's like the last thing you think of food.

I think rocks as food is just, like, the,

joke 'cause it's like, what could you think of that's less food than rocks?

But those bacteria, it's hold my rock.

I mean, at that point, you're pretty much

saying life could exist anywhere.

Yeah, it's very possible.

Yeah.

As long as it isn't, So horribly violent that it kills them.

And not even the most extreme we've seen.

There's actually a, I think it's a slime mold, but it's definitely some form of

bacteria that exists in the radioactive rooms in Chernobyl, and it actually feeds

off of the gamma radiation coming from The broken down core.

And they found that it uses melanin, which is the stuff that

causes your skin to have pigment.

It basically uses that to harvest gamma radiation and,

and uses that as a food source, which is just absolutely crazy.

it is really crazy to think about because that it is quite

abundant as well in those areas.

you can see the, the sheets of it.

And this organism either formed after Chernobyl happened to be effective that

way, or- Was it already an organism that existed that was able to just

detect this and start feeding off of it?

I assume it was through selective breeding, right?

Like, there's actually a really interesting video.

You can find it on YouTube.

I think it was Stanford University, don't quote me on that.

But they, took some bacteria and put it in

an agar dish where each band had a- an increasing

amount of antibiotic.

like, no antibiotic, 1x antibiotic, 10, 100, 1,000, 10,000.

Mm-hmm.

And just through selective breeding, bacteria slowly made its way and became

resistant all the way up to the 1,000.

So I, I'm wondering if it's a situation

like that, where you have, you know,

effectively this brand-new ecological niche opening up.

You- you have this melted-down radioactive zone.

It kills everything else, and you have bacteria existing right on the,

like the edge of this, as close as it can exist.

And just through random selection, slowly becomes

more and more and more immune to that radiation,

but then also is able to actually not just withstand the radiation, but

starts treating it like a food source.

man, that- that's so interesting.

So now this bacteria that's also feeding off of this radiation,

is it choosing that over, other processes?

Or, is it doing it out of necessity?

Like, is it in a dark room with no other living creatures?

the elephant's foot, the, the room it's in is dark, so

there is no other light available.

But I think it's also just taking advantage of an open niche.

That's what life does.

Mm-hmm.

And so you have this, open niche that nothing

else is competing in.

You have no predators if you move into this niche, so I think it's

just an opportunistic area where a bacteria happened to find itself

in the right place at the right time to evolve and take advantage

Of that.

So I don't think it's a case of it's denying other food sources.

It just specced into a different path of life.

Yeah.

It- it's such a cool real-life, showing of how a planet with more extreme conditions

could have life that instead of choosing to fight over resources, just flows into

a niche and just forms its own instead.

I know I mentioned this when we… We did an extreme life

episode a while back, but I, I mentioned and I gave an example

where you might actually have a planet orbiting a black hole where

the accretion disk produces a lot of gamma radiation, but not a lot of

visible light, at least not as much as, A star, especially 'cause you have

to be further away from it to even have a remote chance of life, right?

so maybe this could be an energy source for life on planets like that,

especially if you have a water world where the water offers some type of

shielding to the gamma radiation, so you do get that concentration gradient of

radiation as you go down the water table.

that might introduce a way for life to form in lower radiation areas, and then

maybe slowly evolve and migrate up.

And that could be another interesting basis for a planet that survives on

radiosynthesis instead of photosynthesis.

another crazy one that I kind of stumbled across this episode, and I'm

not a biologist, so I'm not gonna go super in depth into the mechanism 'cause

I, I have to admit my own ignorance

here, but I do think it's fascinating, which is that bacterium, right?

have flagella, which are how they move around, right?

They're like these little, almost looks like a,

like a long hair that they can move and wiggle, and that's

how they move themselves.

And they're actually, A really fascinating appendage from,

An evolutionary perspective for a lot of reasons.

People who were kinda evolutionary deniers for a long time pointed

to the flagella because it's, Completely detached and able to spin

360 degrees, and a lot of people argue that there's no way evolution

can come up with something like that.

Of course, it can, and we found a way that it could happen,

a little bit of a tangent.

But the interesting thing, right,

is they actually use a proton motive force to spin that little flagella, and

they basically break down ATP, produce a concentration gradient of protons, and

then that's what causes the flagella to spin, and that's about my understanding

of that actual chemical mechanism.

Not a biochemist.

I tried to start a PhD in biochemistry, it wasn't for me.

Lucas was there for that.

But that being said, what they found is that if you actually take those

flagella and you spin them with an external force, that process works

backwards and they can actually use that mechanical energy, and produce ATP.

And so this actually opens the door for potentially harvesting mechanical

energy sources to power biological life.

Now, as far as I know, we've never actually found an example of an

organism that actually survives off of that, cause I imagine,

As far as energy goes, that's, Gotta be one of

The most inefficient ways to make energy, but it is a way to make

it, and if you got nothing else, that might be a viable option.

it would essentially work like one of those old flashlights, you know- Yeah

… the ones where you would crank them.

It's a dynamo.

It's an electric generator.

Exactly.

A biological electric generator, and it exists on life on Earth.

Which is Really insane because, like you said before,

cr- being able to create a free-spinning object that can

generate similar to a windmill or, A motor, but then you have life that

can dual purpose it into both their mode of transportation and then when they

need it, convert energy into ATP, is really crazy to think how far that

could go in optimization and just how absolutely broken it could be in,

like, a planet with a lot of motion.

Yeah, I was thinking of it in terms of, Maybe those red dwarf orbiting

planets we were talking about where they have these permanent almost,

currents that are continuously flowing.

I could maybe potentially see life happening there where,

You've got these little flagella that are basically flapping in the currents and

generating energy, and maybe that's how they sustain themselves, and maybe that

could serve as a basis for a food chain.

when you think of, creatures that do that now,

like, sponges and barnacles that,

like, hang their appendages out to catch food.

But if these were the bottom of the food chain, they could just stick

themselves to a hard object in the current and just let the flagella turn, and

they would have an infinite power source, whi-which is insane.

Yeah, I think when you say infinite power

source, some people might think, "Well, that,

that kinda nags my brain a little bit 'cause that sounds

like it's breaking physics." But it's,

not any more than photosynthesis is.

It's not energy from nothing, right?

The energy's coming from that planetary motion, which ultimately is coming

from nuclear fusion from the star.

So it's not free energy.

But it is harvesting energy from your environment, just

like how photosynthesis does- Mm-hmm

just in a much more interesting way.

Yes.

very different than photosynthesis, but absolutely, , everything

starts with our stars.

Yeah, and I was kind of taking this concept and going

a little further with it, and This one does nag my brain.

I feel like there's gotta be something I'm missing, but I'm gonna put the idea

out there anyways, and maybe someone will correct me on why it's wrong.

But I was thinking, if there's no other energy available

and you really have to take advantage of what energy's around you, what

if those flagella get small enough that they can actually take advantage

of Brownian motion, which is the random basically jiggling of atoms

that just happens all the time?

And if you had enough really, really tiny flagella, I wonder if

it'd be possible for them to just getting bumped around by the moving

of the atoms around them could maybe generate a little bit of energy.

It, it would not be a lot, but if it could, that could be a way for life

to not just take advantage of mechanical energy, but thermal energy as well.

So if you had, like, a really hot planet,

maybe that's a way that you could just harvest that

energy directly and actually take a-advantage of as well.

Now, the reason that this kinda nags my brain and I feel like I'm

missing something, full disclosure, is when we think about life

existing, we usually think of, temperature gradients or energy

gradients that it exploits.

And as far as I can tell, if you're in an environment and

everything's the same temperature, it doesn't seem like you should

be able to harvest that energy.

So I do feel like I'm missing something there.

But I'm wondering if it's possible, and it

is interesting to think about if it is.

it definitely is interesting to think about.

like you said, it wouldn't be a lot of energy because,

the gradients are what cause for the flow- and that's what allows for them to be in

the middle of it and harvest such a thing.

So if they're using Brownian motion, just any atoms bouncing off of them,

it would still be occurring, but it would be really cool to see if a

creature like that could evolve to become more and more efficient at it.

Essentially, like, they, they could use, like,

giant flaps- to catch these atoms.

If they could do it, that would by far be the most broken way of living.

honestly though, You wouldn't want anything

too big 'cause the issue is it needs to be bumped by the atoms.

They get too big and then you kinda lose that.

But yeah, absolutely, I could definitely see them taking advantage of it

from an evolutionary perspective.

Mm-hmm.

But yeah, long story short, that's, there's a lot of different

interesting ways that life might be able to generate energy.

But I do now kinda wanna move on just a little bit- Yeah

and start talking about what these whole ecosystems would look like.

'Cause we've, we've put a lot of time into what

kind of planets this could exist.

We put a lot of time in talking about the different mechanisms

they could take advantage of.

But I do kinda wanna think about now what would the,

wider ecosystem look like with all of these different energy sources serving

as the bases of that food chain?

a lot of it I feel like wouldn't be too different.

some of them would have their specifics.

If we go back around to , geothermal vents, I could see an ecosystem

based around these small pockets.

as these fissures form, there could be nomadic break-offs of ecosystems

that go out and essentially survive by, following currents if it's a water

planet, and finding these new areas with plentiful resources to attach to.

Yeah, I could definitely see that.

I was thinking about maybe in a planet like Europa, you might actually

have bacteria that is able to go, kinda like tardigrades, right?

They can go into, like, a state of stasis

essentially, right?

Mm-hmm.

Like a, a hibernate dormant s- state.

And maybe, when they get blown away from the hydrothermal vent, they enter

the state, and they float around the ocean for a very long period of time

until they maybe are reactivated by temperature, and that's how they

colonize and move on to new vents.

So I could certainly see that.

but I do disagree with you that it would be similar.

I think it would be fundamentally different from all of the

ecologies here on Earth for a couple of big reasons, actually.

Okay.

For one, your net energy is going to be so much lower.

you are gonna be in an energy-starved environment.

Mm.

And I think the best parallel to what this would be like would be almost,

like, The deepest parts of our ocean where there's basically

no food, there's no energy.

but even then, right, even on Earth, the deepest parts

of our ocean, most life there forms by taking advantage of,

marine snow- Mm-hmm and, like, all of the,

the things that fall from the ocean.

But you wouldn't even have that.

So you're gonna be in, like, truly a food-starved environment,

regardless of what form of energy we're talking about here, chemosynthesis,

Especially the, Different types of

motion synthesis, right?

That's not a ton of available energy.

So you're gonna end up in an environment that is really slow,

you're not gonna have these fast predators.

A lot of it's gonna be kinda sit and wait, maybe ambush type-

Mm-hmm if, if that exists at all.

Or you might not even really have predation.

Maybe, Single cellular predation, but the issue

is, is every step you move up a food

chain, you lose a lot of energy, right?

Right.

I think maybe in science class we've all seen that,

right, where you have grass and then,

the thing eats the grass, you lose 10 times the energy.

And then the thing eats the thing that eats the grass,

and by the time you get to, like, a cheetah, right, like

most of that energy that was harvested by the grass is completely gone.

And so if you imagine if you're already starting with such a limited

source of energy, you're not going to have the ability to get very

far away from that initial source.

So you're not gonna have these huge apex predators, and your food webs are gonna be

quite limited, maybe only one or two steps removed from the initial food source.

It actually, , makes sense.

if we're thinking of it that way, like, a,

a creature kinda like a jellyfish would be top predator.

yeah.

Just maybe that's, like, one step removed, where

it's harvesting all of the bacteria that's existing.

Mm-hmm.

And I was thinking, too, right?

I mentioned this idea that you might have bacteria that gets thrown from

these hydrothermal vents and then floats around in the ocean to find the new one.

Maybe that's where you have filter feeders existing and actually trying to harvest

these, quote-unquote, "spores," right?

And catch them and use them for an energy source.

it is, very interesting to think about because with that

limited source, something that takes a lot of energy is brains.

Yeah.

Yeah, absolutely.

mental power.

So there could be life that just never chooses to spec into intelligence,

and life that could've been around millions of years before us but will

never come to our level of advancing.

And that'll actually probably fall true for most of these energy sources.

I would absolutely think so, yeah.

I mean, we see it already on Earth if you go to,

The really deep parts of our ocean.

not to say creatures get dumber, but yeah, they invest less in, brain power

because it's extremely expensive, and also just not that advantageous

In an environment like that.

You don't need complex strategy because most of your strategy just

exists on sitting and waiting.

And even on Earth, where we actually have quite a lot of energy, brains

are very expensive, and it's already quite a hard evolutionary path

to go around in energy abundance- Mm-hmm

much less in energy starvation, right?

Absolutely.

There is another key difference, though, between these types of environments

and an Earth-like environment, if you don't have photosynthesis, you

don't have an oxygen environment.

So not only do these creatures have to take advantage of

this lower form of energy, right,

like chemosynthesis, radiosynthesis, what have you, but they

also have to be anaerobic.

They're not taking advantage of aerobic respiration, and that's a huge deal

because anaerobic respiration is a lot less efficient than aerobic respiration.

So if you don't have oxygen, have even less energy available from

The limited energy sources you have.

And so that's a pretty big deal as well, and it also just

means without free oxygen, that changes your environment a lot.

Yeah.

what is the byproduct of synthesis?

I have no idea.

Yeah, me neither.

, And it's not oxygen, though, I know that.

No, it's not oxygen.

ah, God, I looked it up too, and I forget what it is, but it's,

effectively, I think, a bunch of different sulfur compounds.

It is worth pointing out , On Earth, the chemosynthesis that happens

I believe is still aerobic respiration.

It takes advantage of the free oxygen in the ocean.

So even on Earth,-, where the chemosynthesis is

So that, that is gonna change things quite a lot.

I was toying with the idea, and, and maybe this is possible,

I couldn't find… 'Cause this is so far removed

away from life on Earth, it truly is very speculative.

But I, I was kinda toying with the idea that

maybe, if there was some chemical pathways

available, you might actually have life forming oxygen anyways,

especially if you have water available.

Maybe there's a process by which they can split the oxygen

out of that water and use it.

the issue is, is that it takes a lot of

energy to split water into, oxygen and hydrogen, and I

think realistically it'd be a net energy loss, not a gain.

but perhaps there's some catalyst and some evolutionary pathway that could

happen to catalyze that and make it work.

I don't know of one, but maybe there is.

So let's say that there is.

Mm. I still imagine that's gonna be a very,

very metabolically expensive path.

So if that does happen, it's likely that anything that does choose to go that

route and produce oxygen isn't gonna just release it into its environment,

put a lot of energy into making this oxygen, unlike on Earth, where it's pretty

easy for photosynthesis to make oxygen.

They can already take advantage of the sunlight coming in and

use that to, pay some of the bill to split that carbon dioxide.

No, you've gotta put all of the energy in to split the water,

and, and it takes more energy to split the water anyways.

So I don't think you're releasing that into an environment.

You're, hoarding that oxygen.

that could even be kind of another food source, too, right?

Like, it wouldn't surprise me to see other organisms

preying on those organisms that produce oxygen

and using them, as a way for them to get free oxygen.

I mean, that's kind of already how life on Earth

formed.

That's why you have, chloroplast in cells that's

basically that same pathway.

It got gobbled up, and it's kinda like how mitochondria work, too.

Yeah.

They're kind of two cells.

But it is worth pointing out that that is maybe

something that could happen it would make sense that,

There would be predation on these creatures both

producing and storing oxygen, you know, sort of

like little mini oxygen camels.

And then, something comes in and continues to consume them, but

eventually along their evolutionary tree they decide to work together.

You could actually see, Almost fundamental cell,

Differences where the cells are actually within the body producing

oxygen in multicellular organisms.

Yeah,, It's basically how the into animal cells are… I mean,

really that is how the chloroplast got absorbed

in plant cells, so.

Exactly.

It's so interesting to think about, Again, multicellular organisms would be

few and far between even in this point because the energy is so much less.

But it would be cool to see that, trait, and think of what those

creatures would be like.

Yeah.

And it is worth pointing out, and this kinda ties back to what you said

before, you might have had life on these planets around long before life

on Earth formed, and still have not gotten to that point of having a complex

and kind of eukaryotic cell, even if life has been around longer than on

Earth, just because of how glacially slow these processes have to happen

in these energy-starved environments.

So you're gonna have evolution at a

glacier speed on these planets.

So even though these environments might have been around for billions of

years, they might really look like the first formation of life on Earth still.

just don't really see a way around that unless they get to a point to where

they're, like, perfectly, taking the energy from these alternate sources.

and even then, like you said, there's nothing that we've seen in our universe

so far that is so readily available, to give consistent energy as photosynthesis.

I guess really the only one would be radiosynthesis.

I could genuinely see that being a way.

I do think it's overall much less efficient than photosynthesis.

Gamma radiation is just a really hard thing to catch and use.

but, that's the only case where you can

actually see you having a planet bathed in an energy source, kinda

like how photosynthesis works, versus geothermal vents, which only happen

in isolated pockets, or trying to take advantage of mechanical energy-

Mm-hmm which you can imagine would be really tricky.

I do like the idea, though.

If you did take advantage of mechanical energy, maybe you would see,

Almost rafts of organisms form where they can,

Take advantage of tidal motions or wave motions.

or maybe they, Link together so they,

Flap around in a, high current area and just try to maximize

the movement to take advantage of that.

And that serves as a, Basis of a, ecology, but, highly

theoretical, highly speculative, and I imagine still would be a

very, very energy-poor environment.

And again, it'd be like what we said before, probably no production of

oxygen, so these are all gonna be having to rely on anaerobic processes.

And again, predation is probably gonna be very,

very limited and maybe only one step removed from the primary energy generator.

It's definitely an interesting concept, thinking of giant raft creatures,

floating around to be able to harvest that.

But definitely in, An ecosystem where you're harvesting

mechanical energy, it would seem almost, Crazy to have predation even because

you're trying to optimize just going with the movements of the earth around you.

So you're… What?

Now you're banking on, "Oh, hopefully I bump into somebody- Yeah, for

real … and I just get to eat them"?

Yeah, absolutely.

right?

And then on top of that, like, chemosynthesis is already not the

most energy-rich way to run life.

Like, when you look at these hydrothermal vents, which use aerobic respiration,

they're fairly active, compared to, like, the environment

around them, but still not, like, crazy.

And especially if you look at, the bacteria that exist

Deep in the earth's crust that's relying on, like,

iron for food, right?

and I still think that, trying to harvest mechanical energy

would be even less energy than that.

Can you even get enough energy to, keep a cell alive, and much less enough

energy to keep a multicellular predator alive, that seems like a stretch, but

I think anything's possible, as long as it doesn't break the laws of physics.

I don't see why that does, and I could see a very,

very basic ecosystem forming from that.

Yeah, I could too.

I hope you enjoy that episode.

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We do really appreciate all of our supporters for making this all possible.

Please consider joining us next week.

We're gonna be talking about what life might be like for people who

live in our outer solar system.

If you've watched The Expanse and you know who the belters are, that's kinda

what we're gonna be talking about here, people who live in the asteroid belt,

people who live in those outer planets and actually have to make a living out there.

Is it gonna be like a frontier?

Um, I don't know.

We haven't decided on what that's gonna be like yet.

I need to do some research, but- That's right … I think it'll be a fun topic.

If you're a fan of The Expanse, I think it'll be,

a fitting one for you, and I hope you join And watch.

We'll see you guys next week.

Take care.

Bye-bye.

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