Bordering on Fridge Logic levels, how did natural selection create squids (and octopi) who live on land when water was covering the surface and reducing the land, therefore making living in water better off in the long run?
Evolution isn't a process that's aware of stuff like that. Some sea creatures became land dwelling, and everything went swimmingly for them, so they thrived. Land didn't become a problem for these creatures until fairly recently with the war with the Octarians; and even then, we don't know for sure if the reduced land is really a serious problem, or a result of a group becoming greedy with the one they had at hand.
It's probably the same process that occurred with Zoras evolving into Rito in The Legend of Zelda: The Wind Waker. The evolution for a life on land occurred before the rising sea levels became a problem.
Actually, evolution creating squids and other sea life that could survive on land makes sense, as the land was pretty much free of potential predators thanks to humanity and other land-dwelling animals having been wiped out.
This is answered in Splatoon 3. The liquid crystals that kickstarted Inkling/Octoling evolution were imbued with human desires to return to the surface, giving the sea creatures these same instincts to migrate onto land, practicality be dammed.
So if the Inklings dissipate in water what happens when it rains?
They can probably handle regular rain just fine. It's not like falling into water itself. Now downpours? Probably a good idea to have a roof nearby. At least they can respawn after being splattered.
Umbrellas are a thing. And even if they get splattered during a downpour, I guess there's "save points"/"spawning pools" nearby they can respawn at. Hey, they'd be built by the government if they were needed, just like schools and hospitals... and how stop lights are at every important street corner and such.
They have water-proof clotthing/can just wear rain coats.
All damaging weaponry in Splatoon have one thing in common: they involve drenching enemies with ink until they explode (arguably, even the Kraken)... except the Killer Wail and its 5.1 version. Why do enemies hit by the Killer Wail explode in the shooter's ink color instead of their own, assuming the excuse is that the sound waves make it difficult for them to keep their body together? (Note: In the Japanese version, Killer Wail is called Megaphone Laser, but for now, I'm just assuming "Laser" to them is a generic term for a weapon that fires in a straight line that isn't a bullet, and they still consider it a sound attack.)
Consdering how powerful the Splash Wall is, couldn't a Splash Wall theoretically be hooked up to an ink tank, held by its arms and facing forward, and possibly have wheels or harnesses if it's too heavy to be held continuously? It'd be a one-hit KO continuous weapon with greater range than any Roller or Brush.
Remember, turf wars are a sport; it's not about efficiency, it's about fun! Of course they wouldn't allow something completely broken like that.
That already exists. The Octarians call them Flooders.
So if sea creatures can't swim (well, that's what Cap'n Cuttlefish says, at least), what is a pool doing in Mahi-Mahi Resort? That's an awfully dangerous way to relax.
Inklings are not the only species around. Besides, falling in water is barely a mild inconvenience for them thanks to respawns.
As indicated in S2's New Albacore Hotel map, it seems to be primarily jellyfish and the like who use the pools.
Maybe it’s Sea Water that inklings can’t go into but pool water that likely has chlorine is safe for inklings.
It's probably a substitue liquid of sorts or the pools contain something that keeps inklings from dying/their ink dissipating.
Possible Fridge Logic here, but how the hell could have one cataclysmic event wipe out all of humanity? I am not accounting for any interplanetary colonization, which should be considered given the time period. But back on Earth, we've colonized mountains, built on the underground, but how can one huge cataclysm wipe us all out?
Even worse (same troper here): How can there even be a cataclysm of this big of a scale? No tsunami, melting of the ice caps, or whatever else can raise the sea levels can possibly raise the sea levels higher than 400 feet, maybe 1000.
Mega asteroid, super volcano, anything that can block out the sun for a few years really. No sunlight means no plants, and that means no food.
Though the canonical status of it is somewhat vague, a comic in the artbook indicates that humanity was also in the middle of a world war that literally went nuclear.
So the Sunken Scrolls indicated that inklings are invertebrates, and Marie snarks that Callie can't break a bone if she doesn't have any. How the heck are they able to stand then? (considering people hold their shape primarily because of their bones).
Assuming Judd is a normal sized cat, Inklings are even shorter than Hobbits, so that helps.
Maybe their veins are semi-hardened and behave like a skeletal structure.
Speaking of the scrolls, it seems as if all land mammals went extinct following the rise in sea levels and were supplanted by marine life, particularly ones that already showed remarkable degrees of intelligence. OK... and birds survived unevolved because they can migrate and adapt a bit easier, fair enough, insects are probably okay as well... but if all this is true, where the hell are all the whales? Especially since we've seen representatives from basically every other major phyla, save maybe coral? Cetaceans are, in some ways, even more intelligent than cephalopods, so why in the dickens don't they seem to have any representation in the new world?
It's also possible that Nintendo, being a Japanese company, avoided putting any cetaceans into the game because of the continued controversy surrounding Japanese whaling. As Americans are much bigger fans of cetaceans, however, they notice the absence more sharply.
Whales and the like are also very large creatures who might have a harder time adapting to land-based living due to Square-Cube Law, so it's possible there are intelligent versions of them around but they live in underwater societies instead of on land so we just haven't seen them. After all, many elements have drawings of whales and dolphins, like the notice board in Inkopolis and one of the variations of the Nozzlenose, so it seems like our cetacean friends are doing just fine.]
If the human race died out completely, who's running the Squid Research Lab?