So scientists recently unearthed this cave:
https://blog.theearthsite.greatergood.com/movile-cave/
Estimated at 5MILLION years old!
They found all kinds of life but i want to know…
Why is it all bugs? Why is there not larger life forms in this cave?
I also want to proactively counter the idea of “no sunlight to sustain growth via food chain or metabolism”, because in the deep ocean there is also no light, yet we have giant squids, fish, and mega worms…
So why is there no “cave creatures” of comparable size??
In: Biology
Have you ever heard of a *whale fall*?
When whale dies, it’s corpse falls to the ocean floor and when it falls in deep enough waters, the food energy added to that part of the ocean floor results in an explosion of the size and complexity of life that can be supported by the ecosystem in the area.
Whales and other animals swimming around in the ocean and occasionally bringing more chemical energy down to the abyss (called the [Biological pump](https://en.m.wikipedia.org/wiki/Biological_pump)) are why you can get larger more complex creatures there than in a sealed cave.
In the deep oceans dead creatures that were part of the sunlight food chain drift down from above and provide a constant new source of energy. From what I read the cavern is sustained by chemosynthetic creatures and really does lack the energy for much larger lifeforms.
Those deep sea creatures you mention feed on the corpses of the big dead things that sink to the ocean floor. And at the true sunless bottom of the ocean life diversity is very restricted.
But in a cave you dont have that. Its a closed system and there are only going to be so much energy to go around, nothing gets added (or at least not to the level the sun provides to plants). There simply isn’t enough energy in the system to support larger lifeforms.
>Why is it all bugs? Why is there not larger life forms in this cave?
Larger life forms require substantially more energy. We feed the goldfish a few flakes a day but the cat gets a whole bowl of food. Most insects can go weeks without eating, and others even years!
>I also want to proactively counter the idea of “no sunlight to sustain growth via food chain or metabolism”, because in the deep ocean there is also no light, yet we have giant squids, fish, and mega worms…
I can’t weigh in on their size, but deep ocean creatures lack something called a swim bladder (it allows fish to move up and down) so they aren’t crushed under the incredible pressure. Mammals need oxygen to breathe and operate so we’re essentially just one giant swim bladder.
The deep ocean (or midnight zone) *is* still dependent on sunlight. When the goldfish dies (along with phytoplankton, plants and any other fish or mammals), it sinks and becomes food for the inhabitants near the ocean floor.
>So why is there no “cave creatures” of comparable size?
TL;DR (basically) The ocean is boundless, and likely much, much older than that cave system. There was simply more time and more resources for it’s inhabitants to evolve. More selection equals more variation and so on. For any “larger” creature to evolve and/or survive in a cave system without sunlight they’d have to find a sustainable source of energy to maintain their higher demand.
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