Timeline for Why do most fish wiggle their tails side to side, and not up-down?

Current License: CC BY-SA 4.0

57 events

when toggle format	what		by	license	comment
Jul 5 at 16:51	vote	accept	AlphaLife
Jun 24 at 0:00	comment	added	BioPhysicist		@KDP "The assumption that organisms would generally evolve to the most efficient solution is a trivial conclusion from biology" Not "most efficient", but at least most advantageous to survivability and reproduction in the given environment of the organsim.
Jun 23 at 16:26	comment	added	KDP		for those voting to close this question, a question about whether it is more efficient to propel an object with a with a side to side motion of a tail rather than an up down motion is about physics, not evolution. The assumption that organisms would generally evolve to the most efficient solution is a trivial conclusion from biology and this question does not involve biology beyond that assumption.
Jun 23 at 16:01	answer	added	David Bailey		timeline score: 4
Jun 20 at 14:06	comment	added	fishinear		I cannot think of any physical reason. And given the fact that aquatic animals that swim with horizontal tails that flap up and down (dolphins and whales) also exist, I would assume that neither has any significant physical advantage.
Jun 20 at 9:51	history	edited	AlphaLife	CC BY-SA 4.0	added gravity in image
Jun 20 at 9:30	comment	added	AlphaLife		@Puk the tail motion with respect to gravity. The shape of body is irrelevant.
Jun 19 at 22:55	comment	added	AlphaLife		@Puk Up is the direction against gravity. The coordinate system is defined with the positive y axis pointing against gravity.
Jun 19 at 19:30	comment	added	Puk		It is unclear to me if you are asking about the tail motion in relation to gravity, or in relation to the shape/orientation of the rest of the fish's body, or both. (1) How do you define "up" (i.e. the $+y$ direction)? Is it defined as $-\vec g$, or in relation to the fish's body? E.g. which way would you characterize the tail motion of a halibut? (2) Are we considering the shape of the fish's body (which way it is "flattened") or can it be assumed cylindrically symmetric about the "spine"? If it's the latter, it would appear you are asking only about the tail motion with respect to gravity.
Jun 19 at 18:11	comment	added	hft		(Anyways, the question seems to have been reopened and I didn't vote to close it.)
Jun 19 at 18:09	comment	added	hft		I don't know what rule you are violating. You might be able to figure it out by reading this: physics.stackexchange.com/help/on-topic
Jun 19 at 18:06	history	reopened	AlphaLife gandalf61 Jos Bergervoet
Jun 19 at 18:05	history	edited	AlphaLife	CC BY-SA 4.0	added 435 characters in body
Jun 19 at 18:03	comment	added	AlphaLife		@hft Sure, I don't have any problem posting in bio SE. But I want to know what rule I am violating here. I think there is more physics than biology in my question. Similar questions have been asked before, and the tag Biophysics exists. physics.stackexchange.com/questions/153538/… . physics.stackexchange.com/questions/625503/…
Jun 19 at 17:42	comment	added	hft		It is hubris to think that all question can be answered by "physics." I am not suggesting hubris on the part of OP. I am just suggesting that other divisions of science exist for a reason and should not be thought of as secondary or as ultimately deriving their validity from physics. It is OK to ask a biologist.
Jun 19 at 17:41	comment	added	hft		...and I want to seek the answer." OK, so seek the answer elsewhere. Is that a problem? You want to ask us the best way to fill out your tax forms here too?
Jun 19 at 17:37	comment	added	AlphaLife		As far as I am concerned, I am curious about a phenomenon and I want to seek the answer. Why should all these details, matter more than answering the question? I may be misunderstanding; I am sorry if my question was not clear; but I think I have made what I want clear through the edits and comments.
Jun 19 at 17:31	comment	added	AlphaLife		@DavidBailey Agree. This is one aspect here in this community I don't like. I feel people tend to get too stringent in the details, that they forget the essence of a question.
Jun 19 at 17:27	history	edited	AlphaLife	CC BY-SA 4.0	Edited to highlight the actual question I intended.
Jun 19 at 16:59	history	rollback	Kyle Kanos		Rollback to Revision 7
Jun 19 at 16:59	comment	added	Kyle Kanos		@DavidBailey that is what I could call a radical edit that changes the question asked so wildly that the two posted answers are, in large part, now invalid because they address other aspects that you have removed. Thus, I am rolling the change back to what OP asked.
Jun 19 at 16:49	comment	added	David Bailey		I have made an edit that emphasizes that this is a physics question and voted to reopen. I could have eliminated all reference to fish or cetaceans to make it a "pure" physics question, but that would not reflect AlphaLife's inspiration for the question. Biophysics is an important branch of physics present in many, many university physics departments.
S Jun 19 at 16:41	review	Reopen votes
Jun 19 at 18:06
S Jun 19 at 16:41	history	edited	David Bailey	CC BY-SA 4.0	Clarified and emphasized the physics question. Added to review
Jun 19 at 15:11	history	closed	Kyle Kanos Miyase Jon Custer		Not suitable for this site
Jun 19 at 13:17	review	Close votes
Jun 19 at 15:11
Jun 19 at 13:14	comment	added	AlphaLife		@KyleKanos All I am asking is, whether moving a vertical fin side to side more efficient than moving a horizontal fin up and down in water for fish propulsion, in terms of the fluid dynamics involved. I don't think that's a biology question, nor would I get a good answer from their forums.
Jun 19 at 12:58	comment	added	Kyle Kanos		The physics part of the question is essentially "their bones are lined up for side-to-side propulsion" but OPs real question is "why fish have their bones lined up that way" which isn't physics at all
Jun 19 at 12:57	comment	added	Kyle Kanos		I’m voting to close this question because it is a question of evolutionary biology and ought to be asked on Biology
Jun 19 at 9:34	answer	added	Andrew Steane		timeline score: 3
Jun 19 at 6:30	history	edited	AlphaLife	CC BY-SA 4.0	added 109 characters in body
Jun 19 at 6:11	history	reopened	Puk David Bailey Vincent Thacker
Jun 19 at 3:27	comment	added	David Bailey		This is an interdisciplinary biophysics question that I am voting to reopen. Although closely related questions have been asked on Biology SE, i.e. "Best tail for swimming?" and "Why is there a difference in the rotation of the tail fin in fish compared to marine mammals?", the physics question - is there any difference in propulsion efficiency for horizontal or vertical tails - is not answered there. Note that the answer may differ when swimming near or far below the surface.
Jun 19 at 1:57	review	Reopen votes
Jun 19 at 6:11
Jun 19 at 1:56	comment	added	Puk		I think there is a valid physics (fluid mechanics) question in whether side-to-side motion of a vertically-oriented tail has some kind of advantage in propulsion over up-and-down motion of a horizontally-oriented tail, when paired with the rest of the body of a typical fish, which is typically more "tall" than "wide".
Jun 18 at 22:52	history	closed	Solomon Slow Matt Hanson Jagerber48		Not suitable for this site
Jun 18 at 22:51	comment	added	Jagerber48		This is a good question in my opinion, but I think it would be better answered at biology stack exchange (biology.stackexchange.com). Also voting to close since it's more of a biology question than a physics question. Though of course physics will play into the answer.
Jun 18 at 18:10	comment	added	Stevan V. Saban		In side to side wiggles, the tail doesn't fight the force of gravity.
Jun 18 at 17:37	history	edited	AlphaLife	CC BY-SA 4.0	made eyes bigger, which is very important
Jun 18 at 17:13	comment	added	LPZ		A little physical insight on swimming fish: “How do fish swim so quickly?”. The OP appeals for a physical explanation not an evolutionary one, so I think that it is relevant for this site.
Jun 18 at 16:59	history	edited	AlphaLife	CC BY-SA 4.0	deleted 3 characters in body
Jun 18 at 16:51	history	edited	AlphaLife	CC BY-SA 4.0	edited title
Jun 18 at 16:49	comment	added	Bob D		Could it be for propulsion?
Jun 18 at 16:44	answer	added	Rich		timeline score: 0
Jun 18 at 16:12	history	edited	AlphaLife	CC BY-SA 4.0	deleted 86 characters in body
Jun 18 at 16:11	review	Close votes
Jun 18 at 19:05
Jun 18 at 15:57	comment	added	AlphaLife		Let us continue this discussion in chat.
Jun 18 at 15:55	comment	added	Solomon Slow		I’m voting to close this question because it's not a question about physics.
Jun 18 at 15:54	comment	added	Solomon Slow		Sure, whatever. The fact is, some aquatic animals are doing just fine with tails that move side-to-side, and some others are doing just fine with tails that move up-and-down. So, it seems to me, that ought to prove that there is no physical reason why it must be one or the other. Both strategies work. It's all just accidents of evolution.
Jun 18 at 15:47	comment	added	AlphaLife		@SolomonSlow No, I asked why it is mostly that way. There are a lot of exceptions.
Jun 18 at 15:40	comment	added	Solomon Slow		If you asked why it must be that way, my comment suggests that it does not have to be that way. Fish wag their tails side-to-side, whales wag their tails up-and-down. Both of them have survived to the present day, and if it weren't for humans hunting them and messing with their environment, neither group would be in any danger of extinction at this point in time.
Jun 18 at 15:38	history	edited	AlphaLife	CC BY-SA 4.0	added 121 characters in body
Jun 18 at 15:36	comment	added	AlphaLife		@Triatticus yes, but I believe most things in biology have evolved, to reach some configuration which may be explained with physical reason s.
Jun 18 at 15:34	comment	added	AlphaLife		@SolomonSlow my question then would be why it has to be like that in the first place. Why the horizontal fin in the first place. yeah whales dolphins and all mammals are exceptions, which is why I told "most" fish.
Jun 18 at 15:23	comment	added	Solomon Slow		Fish tails have vertical fins. Wiggling them up and down would have much less effect than wiggling them side to side. Whales, on the other hand, all have horizontal fins on their tails, and whales wiggle their tails up and down. (And, if anybody's wondering about pinnipeds, they don't swim with their tiny little tails. The "fins" on the back end of a pinniped's body are their feet.)
Jun 18 at 15:18	comment	added	Triatticus		I don't know that this is really a physics question since there exist plenty of aquatic life that does it the other way. But I'd be surprised if someone knows the reason.
Jun 18 at 15:16	history	asked	AlphaLife	CC BY-SA 4.0

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