Bay 12 Games Forum

I specifically used dolphins because they are of a comparable intelligence to humans and are closer in size to a person than a sperm whale is.

I kinda doubt the claims that dolphins have intelligence similar to humans almost as much as I do the claims that they're significantly more intelligent than sperm whales. Besides, those factors aren't exactly enough to explain how the sperm whales can stay underwater for several times as long as the dolphins do.

And yes, I am assuming baseline human metabolism...Short term, the effects are minor, since we do have limited enzymatic function - it's why people with fevers or hypothermia don't immediately drop dead - but in the long term it's deadly.

And every one of those functions is one that is absent or less energy-consuming in some animal or another. There's no reason for this hypothetical Thuun trying to be a fishman to stick to baseline human stuff.

So I'm assuming that if Thuun has gills, it's because he wants to be able to operate underwater for long periods of time without incredibly essential functions being disabled. That means maintaining a humanlike metabolic level and core temperature.

Because there aren't creatures which operate perfectly well at lower levels and temperatures?

To have a physiology suitable for extended periods of either aquatic or terrestrial use through a wide range of biomes (and maintaining humanlike cognitive ability, probably the most important point) would require building a creature entirely from scratch, because if you're going to alter that much genetic code you may as well just tear it all into bits and play lego. I have no idea of how to even begin mapping out such a creature.

Bit by bit. Add one thing, figure out what needs to change to let that work, etc. Repeat.

You might be able to start with a human, but the result would be as closely related to a human as the common banana is, I suspect.

So?

The exceptions are pretty much exclusively sharks and a couple of fish which are large, oily and eat a shit-tonne. The sharks that pull it off dine on dolphins, seals, penguins; good red meat with plenty of energy. Fish flesh is not exactly energy dense, y'know? The oily fish that do... couple of kinds of tuna, mostly. But they also pretty much just constantly eat.

Humans also consume pretty good amounts of food for their size. And they are also large.

We agree on something! Awesome!

It's a lot easier to agree when we cast aside theory and focus on practice.

When you have a container at pressure X and the surroundings are at pressure 5X, what happens? As those divers sink, they expel the air from their lungs. It's not entirely voluntary; the water pressure compresses their chest and literally forces them to exhale. By actively exhaling they can at least control the rate to a degree.

Um, actually, it compresses the air inside their chest. Sure, there's less room inside, but there's also less air (by volume) inside. Unless the pressure gets to the point it ruptures a sphincter or something, it won't happen--and by that point you've got other problems. Bigger ones.