Talk:Symmetry in biology

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Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 22 January 2019 and 24 May 2019. Further details are available on the course page. Student editor(s): Ainaharmony.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 10:35, 17 January 2022 (UTC)

Educational assignment - significant updates to the page

Hi everyone,

I am currently updating and attempting to improve this page as part of a science communication project at Imperial College London. For more information on this please see my course convener's page.

Updates so far:

• Added a diagram (made by me) to the introduction to illustrate the three main types of symmetry
• Re-written and improved the introduction to simplify and clarify important points
• Significantly updated and re-organized the radial, bilateral and spherical symmetry sections
• Moved icosahedral symmetry to its own section outside of radial symmetry
• Added new sections about biradial symmetry and the evolution of symmetry (both plant and animal)
• Re-positioned and re-sized all images to be consistent and aligned with the appropriate sections
• Formatted the asymmetry section to include a table and several images as well as additional information and references
• Included symmetry breaking in the asymmetry section along with a figure created by myself to show the molecular mechanism of left-right asymmetry...

I have tried to address problems discussed on the talk page, especially those in the 'to do' section.

If you have any questions, critiques or suggestions please feel free to let me know! Charl Hutchings (talk) 10:28, 11 March 2020 (UTC)

To do

This article has been around a long time but remains in need of work.

1. Check text; if WP:OR then delete, else add citations.
2. Expand and explain the topic a bit better... with citations.
3. Illustrate as needed, create diagrams.
4. Relate Locomotion to Symmetry (bilateral bodies with a front end for eyes, etc).

--- Chiswick Chap (talk) 07:43, 16 April 2013 (UTC)

I've got a Beklemishev reference for #4, as well as a few other papers. I'll try to dig them up soon; please bug me on my talk page if I forget. HCA (talk) 16:59, 16 April 2013 (UTC)

Bilateral Symmetry Not Easily Broken

I had to read this several times, follow the reference and read that several times before it made any sense to me. The wording is very similar to the wording found in the reference, and is too terse (in my opinion) to convey the information. Maybe instead of trying to explain the whole concept all at once, we could zoom in on one of the asymmetrical properties being (unsuccessfully) selected for, then add the fact that other lateral asymmetries were impossible to achieve via selection pressure. For example:

Bilateral Symmetry is difficult to break. Laboratory experiments that tried to select for laterally asymmetrical properties in fruit flies (drosophila) e.g. making the left eye larger than the right, failed. This Was true of _any_ laterally asymmetrical property including uneven wing size, wing folds, etc. However, it was always possible to select for cephalo-caudal and anterior-posterior asymmetries. SCooley138 (talk) 23:09, 21 April 2013 (UTC)

That sounds to me like a poor, near-copyvio piece of editing, in that case. Why don't you rewrite the section along the lines you suggest? Chiswick Chap (talk) 07:39, 5 May 2013 (UTC)

viruses

Some viruses have A5 rotational symmetry, plus mirror symmetry, like a football. I'll try to find a picture, and add something, when I get around to it. Maproom (talk) 16:18, 16 March 2016 (UTC)

Citation 21 about right-handed humans not working

I was interested in reading more about right hand dominance in humans and I followed the link to the citation and it didn't bring to me a scientific journal. Seems to me that citation is improper

7:01 AM 19-9-2018

Citation 21 is to a scientific paper which supports the sentence which it follows. But that sentence is about a fish species, not humans. Maproom (talk) 19:06, 19 September 2018 (UTC)

I've removed #21 (broken) and added refs for each of the human claims. Chiswick Chap (talk) 21:43, 19 September 2018 (UTC)

suck

svey 122.161.52.123 (talk) 05:51, 19 June 2022 (UTC)

Poor terminology

The article frequently uses the term "radial symmetry" to describe what is correctly termed "rotational symmetry".

The point is that the kind of symmetry an object has is described by the kinds of motions of the object that display its symmetry. To call this symmetry "radial" when it is in fact rotational is misleading and confusing.

Better illustrating relation between bilateral and radial symmetry.

The existing illustration

Illustration depicting the difference between bilateral (Drosophila), radial (actinomorphic flowers) and spherical (coccus bacteria) symmetry

shows a fruit fly with bilateral symmetry, a lily with 5-fold radial symmetry, and a bacterium with spherical symmetry. but it overprinted with red lines that are confusing in the case of the lily. For the fruit fly and the bacterium the red lines correctly indicates planes of bilateral symmetry, of which there is one for the fruit fly and arbitrarily many for the bacterium. But for the lily, there are not 3 but 5 planes of symmetry each passing though the center of the flower and the center of one petal. Can someone who knows to do so edit the image file to show this? CharlesHBennett (talk) 21:31, 26 July 2024 (UTC)

The ambiguous term radial symmetry seems to be established among biologists, but it is not the same as rotational symmetry. It is better to speak in terms of under what operations (e.g. rotation, reflection, etc,) the object is symmetric. For example the lily, like an ordinary five-pointed star, has five-fold rotational symmetry as well as 5 planes of reflection symmetry. The letter Z has twofold rotational symmetry but no reflection symmetry. The letter T, like a fruit fly, has one plane of reflection symmetry and no rotational symmetry.