this post was submitted on 02 Nov 2024
129 points (100.0% liked)
Asklemmy
43939 readers
673 users here now
A loosely moderated place to ask open-ended questions
Search asklemmy ๐
If your post meets the following criteria, it's welcome here!
- Open-ended question
- Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
- Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
- Not ad nauseam inducing: please make sure it is a question that would be new to most members
- An actual topic of discussion
Looking for support?
Looking for a community?
- Lemmyverse: community search
- sub.rehab: maps old subreddits to fediverse options, marks official as such
- !lemmy411@lemmy.ca: a community for finding communities
~Icon~ ~by~ ~@Double_A@discuss.tchncs.de~
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
I genuinely fail to see why it's a thing. Like reading up it, it's basically just convergent evolution of crustaceans to a crab-like shape.
Couldn't the same be said for a ton of fish-like animals? The many attempts of nature to develop a fish? Hell, even some mammals went back to the fish, plan, although with the tail-fin the wrong way and having to visit the surface to breathe.
Or large-ish mammals all having pretty much a similar bodyplan, four limbs, head and neck.
Like surely there's something so specific in carcinisation that I just haven't picked up on yet. If someone know what it is pls inform me.
I'm not an expert, but my understanding is that the science indicates all mammals have a common ancestor. Not certain about fish, but I think that's a similar case?
To me, the surprising part about carcinisation is that, the form of a crab seems oddly specific, but non-obvious. I mean, I look at the form of a fish and think, "yeah, it makes sense why that shape would be favored in water," but I look at a crab and think "guess that's just what worked out for your ancestors. Tough luck, buddy." But apparently it's not just bad luck, it's a common strategy.
Did you know humans are more closely related to catfish than catfish are to dogfish?
QI | No such thing as a fish
Yeah, I can see that. But also it's swimming in water. Then again if tou want to crawl around the bottom? Hexapod is probably the way to go. But then you also need to be able ro manipulate shit, so frontlimbs become bigger.
Like a lot of space vehicles meant for surface exploring, both imagined and real, are usually six-wheeled, probably for added stability in a rocky terrain where there's a bit less gravity and sometimes storms and whanot. And what is it like on the ocean floor? Rocky, basically "less gravity" and odd flows like storms.
Idk there's a bit more to it I guess, I'm just looking for what that bit is, or if there indeed is one.
Yeah, that QI clip came to mind when you mentioned it, but to your point the shape that we consider "fish-like" shows up a lot in water. Even whales and dolphins figured out a similar shape, despite them not being fish (though they might still be etymologically related if you go back far enough?)
Ok, I can buy that the shape of a crab is probably optimized for a certain lifestyle.