I seem to recall that marine mammals are the result of water creatures migrating on to the land, evolving for a while, then some of them going back to the water.
“Yo. Fuck this air, guys. I’m going back.”
You wouldn't believe
https://www.livescience.com/28075-how-whales-ancestors-left-land.html
And since all land vertebrates are descendents of fish, and you can't evolve out of a clade, whales actually are fish.
Hell yeah! Fuck paraphyletic groups.
And so are all of us
and eventually they will get out of the water again to become a crab
Sperm whale lungs collapse during their dive
Wouldn’t that be true of any whale’s lungs?
Humans’ lungs get smaller when they dive.
Or do you mean they get flat as a pancake?
Looks like you're right it's not just the sperm whale and the ribcage is flexible in whales so it can collapse
They dive crazy deep, third deepest in the world so I'm not sure if other whales' lungs can outright collapse rather than just flex
Convergent evolution is pretty cool.
