Talk:Rotating locomotion in living systems/GA1

GA Review

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I usually do reviews in 3 stages:

• coverage, structure and flow.
• the nitty-gritty stuff including refs, style, copyediting and copyright status of images.
• lead - once the main content is all OK.

Coverage

Looks good to me, and I've been keen on evolution-related topics for decades. However:

• Pre-inventing the wheel is not a WP:RS as it's a forum, but "given the very large number of bacteria in existence, there are probably more wheels in the world than any other form of locomotion" is dead right. So the interesting question is why no fully-developed wheel-like mechanisms elsewhere in nature? Rotation in living systems jumps from bacteria to multi-celled organisms, and does not consider archea, eucaryotes or protists.
• Wheel-like mechanisms made by animals
  See ‘Wheels’ in nature for discussion and further refs.
• Pseudo-wheels, e.g. AFAIK rotifers' (name means "wheel-bearer") "wheels" have a reciprocating action.

Structure

N.B. Think about this but don't put effort into it until the coverage issue is resolved. I think a re-structure is needed. The concept of an indefinitely rotatable joint is the common element in wheels, propellers, flagella, etc. The 2nd most general element after that is the "motor" and possibly "transmission", for systems that need to rotate actively rather than passively. What would you think of the following:

• Lead (to be done last)
• Overview
  Based initially on current section "Range of motion", which defines the core issue.
  Then revise this 2nd last, when we can see how much of an overview is needed. Why don’t animals have wheels? provides a lot of good explanatory content.
• Difficulties of an indefinitely rotatable joint
  Mainly based on current section "Slip interface"
  Nutrition and excretion
  Respiration
  Repair / maintenance - otherwise the bearing wears out.
• Rotary systems in nature
  Flagellum
  Rotary "mechanisms" of ATP synthase,
• Rolling locomotion in nature
  • Rarity - just a few examples
    keratinocytes
    The golden wheeling spider Carparachne aureoflava of the Namibian desert escapes parasitic wasps by flipping onto its side and cartwheeling down sand dunes - <ref>{{cite journal | author=Armstrong, S. | title=Fog, wind and heat - life in the Namib desert | date=14 July 1990 | journal=New Scientist | url=http://www.newscientist.com/article/mg12717253.800-fog-wind-and-heat--life-in-the-namib-desert-researchersworking-in-one-of-the-worlds-most-hostile-environments-are-discoveringhowscores-of-species-manage-to-survive-but-will-the-research-station-itselfsurvive-as-namibia-gains-its-independence-.html | accessdate=2008-10-11 }}</ref>
    Tumbleweed (and why this is advantageous to the plant.
    Any other relevant examples.
  • Disadvantages of rotating locomotion
    N/B. rolling resistance can be cause by deformation of either or both surfaces, e.g. aeroplane tyres have high rolling resistance until the wings are generating a bit of lift during the take-off run.
    In pre-Roman N Africa and Middle East chariots were common, but the use of wheels declined after the fall of the roman empire (see e.g. A Man with Wheels).
• Constraints of evolutionary processes
• Wheel-like mechanisms made by animals
  See ‘Wheels’ in nature

for discussion and further refs.

• Wheeled creatures in fiction and legend
  Add the g'Kek in David Brin's Uplift Universe (Brin's novel Brightness Reef describes g'Kek in enough detail; aged g'Kek suffer from arthritic axles)
  Stomatopod Biology gives pointers to more SF wheelies.
  Microbe published in the "hard SF" mag Analog Science Fiction and Fact (August 1995) and written by a real biologist (Brin's a physicist, and makes a few mistakes in biology).
  Wheelers (novel),by 2 scientists of whom one is a biologist.
  Pullman's Mulefa are not a valid example as their wheels are tools derived from the seed-pods of a species of tree.
  

I'm not sure the mathematical analysis of stability belongs here, possibly in Wheel. For the purposes of this biology article the point can be explained easily enough by text.

Is anybody there? I posted this review on 11 December 2008 and there's been no response. --Philcha (talk) 16:21, 10 January 2009 (UTC)

Reply

:I've been a bit distracted, but I'll get to incorporating the suggested changes this week. Sorry for the delay. » šᾦῥъ^{τ • ¢} 15:55, 19 January 2009 (UTC)

I've completed incorporating the suggested changes into the article. » šᾦῥъ^{τ • ¢} 21:08, 21 January 2009 (UTC)

• Introduction.

  The introductory sentence is really bad. Encyclopedia articles should use the first sentence to introduce the topic, not to say something about what it isn't: "While the wheel has played an integral role in locomotion of vehicles designed by humans, wheels do not appear to play any role in the locomotion of biological systems." This article isn't about the wheel, or about the locomotion of vehicles, or about engineering, so, we've said what the article isn't about. Now, when are we going to say what the article is about? After you've firmly lost the user? --KP Botany (talk) 02:30, 22 January 2009 (UTC)

Coverage broad but not focussed

The Wikipedia:Good article criteria require coverage that is broad but focused. However I still find it hard to identify what this article is about, which suggests a lot of the material is off-topic or at least given excessive coverage, so that it distracts attention from the main theme. I suggest this is not really a problem in nature, it's a puzzle for human scientists and hence for people who like reading about science - we use wheels so much that the apparent rarity of wheel-like mechanisms in nature looks odd.

So maybe this will work (with working titles that may need to be changed):

• The puzzle
  Define wheel as a system in which one component rotates freely relative another for an indefinite number of turns. We use wheels a lot, for locomotion and power transmission (gears, belt / chain drives).
  There are visible examples in nature of organisms rotating their entire bodies - wheeling spiders, tumbleweed. However no known multi-celled organisms use anything like the wheel+axle combination.
  PS I now think it's best to skip keratinocytes, as the rotation occurs within a single cell but does not involve an axle.
• Flagella
  The only known instance in nature one component rotates freely relative another for an indefinite number of turns.
  Brief outline of how they work.
• Impediments to the evolution of a biological wheel
  • Transfer of nutrients, etc.
    However it might be possible for organisms to secrete non-living rotating components, made of e.g. keratin.
  • Bearing
    lubrication
    repair
    Possibly power, but you'd have to find refs for this. Perhaps no worth bothering with, as there are many ways to transform reciprocating motion into rotary (crankshat, treadmill, dung beetle).
  • Constraints of evolutionary processes
    Needs some polishing, but structure and focus are the priorities for now.
  • Limitations of wheels.
• Wheeled creatures in fiction and legend
  I've omitted "Rolling ...", as the focus of this article needs to be systems in which one component rotates freely relative to another for an indefinite number of turns (I wish I could think of a snappier phrase).
  I'm tempted to re-introduce Pullman's mufela with a comment "however their wheels are seed-pods of a local tree, and the mufela simply replace them when they break down": some one might be tempted to add it later, so might as well show that mufela borrow rather than build wheels; they are analogous to Diamond's non-living rotating components (but don't say that, as it would violate WP:NOR, just give readers the opportunity to draw the conclusion).

If that does not solve the focus problem, I think it would be more sensible to give up for now, i.e. the article would fail to reach GA, and perhaps you can look at it with fresh eyes in 6-12 months. This topic is harder to pin down than it looks. I admit I underestimated the difficulty because I'm familiar with all the ideas, but the aim of a WP article is to explain the topic clearly to a reader without much background knowledge. --Philcha (talk) 09:46, 22 January 2009 (UTC)

I tend to disagree with removing the non-axled, rolling examples (both living and fictional). I think it helps to differentiate the two modes and clarify what is meant by the statement that no multi-cellular creature has a "wheel". That content could possibly be split, but I don't know if it's enough for an article. I think that with the scope defined as "rotation in living systems generally, with an emphasis on the lack of axled rotation" instead of just "axled rotation in living systems", it fits.

I think the second paragraph makes it clear enough that the lack of biological wheels is only an apparent problem, not an actual one.

I think the Mulefa are definitely within the scope of the article.

You've restated an outline for coverage/structure, but I'm not sure what to do with it, since I think those areas are already well covered. It would be more helpful if you could give me a list of specific changes that need to be made.

Thank you again for the time you're putting into this. Even if the article doesn't make it to GA right now, it's definitely a better article than when we started. » šᾦῥъ^{τ • ¢} 15:40, 24 January 2009 (UTC)

Lead (preliminary view)

The proposed first sentence "The rotation in living systems of a body or body part in the fashion of a wheel for use in locomotion is nonexistant in biological orginisms" is ungainly, and misrepresents the main content. I suggest the first sentence should be about the apparent near-absence of wheels or rotational mechanisms being a puzzle for scientists. --Philcha (talk) 09:19, 26 January 2009 (UTC)

The structure of the main content just does not work for me, because it jumps about from aspect to aspect, without explaining why. I've thought about how to structure the artcile on and off of the last couple of days, which is why you haven't heard from me. Unfortunately I've been unable to to come up with anything that convinces me. The best I can think of is what I suggested above (22 January 2009). If you cannot provide a structure that is easier to follow within a week I will have to concluded that the article fails to reach GA standard. I would be disappointed if I had to issue a "fail", because the content is interesting and, on the whole, well-referenced. --Philcha (talk) 09:19, 26 January 2009 (UTC)

Conclusion of review

I'm sorry, šᾦῥъ, I think this review has gone on for long enough and the structure still isn't clear, so I have to mark it as a 'fail in its current state.

I regret this as it's an interesting topic and you've put a lot of work into it. However it's extremely difficult to find a really coherent structure. The best suggestions I can think of are:

• Do a bit more research, especially on other components of rotational systems such as bearings and power transmission systems. You might helpful to make list sources ina section of the Talk page, wiht one-line notes onwhat the goodies in each source are - Talk:Evolutionary history of life has an exmaple, aloth it's much longer you'll need for Rotation in living systems.
• Then take a break and do something else for a couple of months. Hopefully coming back to look at it with fresh eyes will suggest other ideas. --Philcha (talk) 12:37, 1 February 2009 (UTC)

- - - - - - - - - - - - Main review above this, miscellaneous notes below: please keep discussion above this line- - - - - -

Sources that might be worth using:

• Epidermal repair results from activation of follicular and epidermal progenitor keratinocytes mediated by a growth factor cascade mentions "rolling" of keratinocytes.
• Creationism and the wheel "So how do the creationists explain why an all-powerful deity did not on any occasion design an animal incorporating the enormously advantageous rotary motion of wheels? Creationists have no answer to that question. In complete contrast, Darwinian natural selection provides the perfect answer. The wheel is a manufactured object that can only function when it is complete. ..."
• Pre-inventing the wheel is not citeable as it's a forum page, but "About half of all known bacteria have at least one flagellum. ...given the very large number of bacteria in existence, there are probably more wheels in the world than any other form of locomotion" adds perspective.

--Philcha (talk) 14:53, 11 December 2008 (UTC)

- - - - - - - - - - - - please keep all items related to the GA review above this line - - - - - - - - - - - -