In a world with 45% atmospheric oxygen content

Not a scientist either, but IIRC the size of bugs is at least partially limited by how they breathe (spiracles - little holes in the exoskeleton). Since this means that they're basically breathing by gaseous diffusion, lower O2 content means that the larger ones will start suffering cell death in their internal organs since they won't be able to "inhale" enough O2 for those cells to get any.

t. my ass, probably

To add on to this, the exoskeletons of arthropods would continue to grow until it reached a certain upper limit that is determined by the specific biological limitations dictated by the planet's gravity and available biomass.

On land it would theoretically be possible to see arthropods and arthropod-like organisms that could be as massive as 4 to 5 metres in height in the proposed scenario. However, anything larger than this would require a much more complex biology and physiology, in addition to an enromous biomass requirement in order to maintain the metabolism of such a large body size.

>In a world with 45% atmospheric oxygen content
>Every thunderstorm would also cause apocalyptic hellstorms, because with that much oxygen a lightning can light the air itself on fire in the right conditions. With enough aerosols, short bursts of fire will crack through the sky, raining fire and rain onto the ground beneath.
>Fire would burn so much more easily and strongly that not even the rains of a thunderstorm will put out the spontaneous fires caused.
>Materials that normally don't burn start to burn, just like in a housefire fueled by the wind
>Any kind of spark will cause ravenous hellfires
>Earth is reduced to (flamable) steppes and bushland until the atmospheric oxygen gets lower again because of how much oxygen producing biomass has been burned.

It would be like a forest fire danger zone in california, except everywhere

But we can do this, right? I mean, there's no reason not to try doing this, we can feed them oxygen through special implants and we can gather enough biomass. A bit of genetic editing and we can have 5-meter tall wasps and ants.

Sure, but they won't be able to survive outside of the lab they were created in.

Make Bugs Great Again!

ona related note. how many people would it take to have a fair fight against an ant in gladiatorial combat?

giant ant ofc

>But we can do this, right? I mean, there's no reason not to try doing this, we can feed them oxygen through special implants and we can gather enough biomass. A bit of genetic editing and we can have 5-meter tall wasps and ants.

Short Answer: Even with precise genetic editing and the consideration that arthropods and other similar families of arthropod are prone to microevolution; it would take at least a thousand generations before you see a notable speciation to occur, and that's really simplifying the science of the process.

Depending on the circumstance of the environment, you would probably not see the terrestrial biomes present on Earth today.

At the most, you would see a lot of mediterranean environments, chaparrals, dry shrublands, and arid land akin to the Badlands in North America, or Patagonia.

Have you really learned nothing.

nah we could, they wouldent be THAT big,

user, that's not how it works. Exoskeletons work only to a certine mass point, once that is exceeded you would need extream amounts of musscles mass to even move it. Plus the amount of food you would need to feed that thing would be extream

A lot of bugs use a combination of hydraulics and muscles. i don't know the exact details though.

Wait NVM that's only spiders. Maybe other related animals do so as well but definitely not most bugs.

I don't think oxygen stays around for long, geologically speaking, without a truly lush vegetation. Oxygen often bonds with other atoms forming different molecules over time. In fact, the presence of O2 is a clear indication of plant life.

As an added bonus all that oxeygen is absolutely devastating on a cellular level. Cancer all round

Not if you burn to death first.

...metal

I read in a 1001 facts book when I was ten that if a mosquito was as big as a human its legs would break under it's own weight.

The only semi-plausible way an ultra-high oxygen content could arise is perhaps what happened early in Earth's history, except just "assumed to be more so".

Namely, oceanic bacteria that GITGUD.exe at consuming carbon dioxide and emitting oxygen.

Now, on our world that depleted atmospheric CO2 to such an extent that most/all of Earth froze over completely, curbing the bacteria until volcanoes could burp out enough shit to stabilize the atmosphere. However, a planet closer to its star, or orbiting a brighter hotter star might be too hot to freeze, allowing the bacteria to continue their work largely unopposed.

The oceans would be a blue-green soup of algae/bacteria, protected from lightning and fire by the water they inhabit, and anything that tried to live on land would have all sorts of fun challenges to overcome for survival. Some sort of very effective organic insulation would seem almost mandatory for protection against fire/lightning. It would also need *exceptional* free-radical protection to avoid damage from metabolic byproducts and ozone and such.

That said, anything that did evolve in such an atmosphere would be quite dangerous/impressive. Likely short lifespans, but exceptionally hard to kill and resistant to disease. Possibly very fast moving as well, both because of all the oxygen fuel available, and because running from GIGANIGGAFIRES would be evolutionarily mandatory.

food for thought.

Now that I think about it, you could also have a creature with a massive coat of shaggy hair, (perhaps with metals incoroprated but the chemistry of that escapes me), that would drag the ground for meters behind it and provide a grounding/insulating action against lightning.

When fires come, the hair chars up and forms a crusty shell which the creature can hide inside for a little while. The fires would burn stupid hot, but they would also move quickly. When the creature senses the heat has died down, it breaks free of its outer char layer and moves on, now unencumbered by all but a downier (and thus air-trapping to prevent suffocation/filter smoke/better insulation) underlayer of lighter fur. Might even be a little faster and better at moving long-distances (to escape the burn zone for food?), until the heavy outer coat regrows.

I like where this thread is going

>The oceans would be a blue-green soup of algae/bacteria, protected from lightning and fire by the water they inhabit, and anything that tried to live on land would have all sorts of fun challenges to overcome for survival.
I imagine you'd have sea creatures come on to land for short periods to lay fire resistant eggs out of the reach of predators.

At what total pressure?

Man, he's looking fly.

Mammal-like organisms could theoretically exist

Part of the reason proto-mammals along with reptiles like Crocodiles & Turtles were able to survive the Cretaceous–Paleogene mass extinction event was the ability to enter a state called torpor

Torpor is basically like hibernation

Echidnas still do it today in Australia

They kno da wae

Caves immediately become top priority. It took quite a while for amphibians to advance to making solid-shelled eggs. That step would be painfully difficult on this world, especially since the ultrahigh O2 content would fuck with soft-shelled eggs/membranes/fluids mercilessly. I have a hard time seeing how you could make all those evolutionary jumps simultaneously.

But shoreline caves, sinkholes, cenotes, and the like would be unimaginably precious, since you could let eggs adapt to the air before also needing them to adapt to the fire. I would imagine life would emerge onto land there, since even the "traditional" tidal pool would be a more aggressive environment, and likely 95% already choked with algae and bacteria taking advantage of the shallow water. Deeper yet protected water, *not* exposed to sunlight and therefore disfavoring bloom-choking, would be at a premium.

fuckin rad

What everybody does not seem to see is that besides the aforementioned conditions, humans would be utterly unable to breathe freely there, a few percent above standard is enough to literally stone you out of your mind with euphoria, i don't want to know what doubling it does to you (must be one hell of a trip tho)

>Things are about to... Heat up.
>In the hottest RomCom of the century, Smoke Break

>Over time insects have adapted to have the optimal size compared to the amount of oxygen they can take in.

They didnt adapted, the ones that didnt fit died.

Yes.
That is known as evolution, and evolution's purpose is so that animals can adapt.

Doesn't it also depend on atmospheric pressure?

Stop anthropomorphizing evolution

It has no agency or will

It’s a phenomenon

Storms don’t occur “to create lightning”

>expresso
pls

>expresso
FUCKING DIE REEEEEEEEEEE

It's a phenomenon, and the effect of said phenomenon is to create animals adapted to their environment. I don't know why you're so opposed to anthropomorphization, it's a standard tool of the English language.

>I don't know why you're so opposed to anthropomorphization, it's a standard tool of the English language.
Not that user, but some people take it literally.

I’m fine with the effects explained as such

But it irks me when people imply certain phenomena occur due to a higher agency

They're not implying that, you're misinterpreting a common trend in English.

>expresso
Also,
>not realizing espresso actually has less caffeine per unit volume than regular coffee

>per unit volume
ounce per ounce espresso has about 6 times the amount of caffeine as standard coffee. What the fuck kind of point do you think your making?
>A shot of whiskey doesn't get you as drunk as a keg of beer
No shit you idiot.

Depends on the temperature. If it's a cold world a bit further from its sun than Earth, you might still get mammals living in the areas outside of the equatorial region where insects couldn't survive.

La creatura...

>It took quite a while for amphibians to advance to making solid-shelled eggs
With the right environmental factors, I could see hard shelled eggs developing aquatically.

Alternatively, a semi amphibious species that crawls on to land and dies while carrying eggs/young. Something with a hard carapace/shell might be able to leave a corpse capable or surviving fire storms.

>Caves immediately become top priority.
Caves would probably create all sorts of fascinating micro biomes.

I'm wondering what sort of plant life, if any, would spring up in these conditions.

>They didnt adapted, the ones that didnt fit died.

user, that is how species adapt - not individuals, but species adapt through two things:

1) random minor mutations producing small variances in the population (slightly bigger, a bit more red, eyes slightly further apart, sharper spikes on the shell)

2) environmental pressure killing off the ones that don't fit (oops, more red makes you stand out and get eaten more often, but eyes further apart improved depth perception to avoid incoming predators slightly better) and encouraging the ones that fit their environment better (sharper shell spikes make it harder to grab, and thus less likely to be eaten, population shows an increase in individuals with sharper spikes over time)

As far as evolution is concerned, individuals don't exist, only populations and statistical averages.

Your lungs dissolve into soup.

Oxygen is one of the top corrosive elements, only outstripped by fucking fluorine.

Maybe. They might be anthropods that develop better cold adaptations.

>I'm wondering what sort of plant life, if any, would spring up in these conditions.
tfw you'll never be a ai built into a god-machine who creates 45% O2 atmosphere planets to watch evolution on as a hobby.

>Alternatively, a semi amphibious species that crawls on to land and dies while carrying eggs/young. Something with a hard carapace/shell might be able to leave a corpse capable or surviving fire storms.

This is a cool idea.

That IS pretty metal.
This is also way metal.

Then you combine the two and cower in fear of the aweful shit known as FOOF. (Diflourine Dioxide)

I think I calculated that a 5 gallon bucket of FOOF was enough to put me into orbit.