Talk:Evolutionary developmental biology/Archive 1

Could be expanded on

1) Evo-devo is not only to understand the evolution of developmental processes. It also helps to understand the development of embryos, for instance, how the morphology is linked to genomic sequences and how this "code" is executed through gene expression and regulations.

2) Emerging genomic data are changing the landscape. Evo-devo, functional genomics and comparative genomics are complementing one another. This helps tremendously in understanding the information coded in genomes and biological processes.

Just my 2cents. I am not familiar enough with the field to write on my own :)

The May 11 issue of the New York Review of Books has an essay by Israel Rosenfeld and Edward Ziff on evo-devo, reviewing From DNA to Diversity, Endless Forms and The Plausibility of Life. This could be a source for improving this article. I could draw on it myself but would defer to someone actually in the field of evolutionary biology. Slrubenstein | Talk 17:58, 3 August 2006 (UTC)

• Reading that book right now. It is very detailed and I'm having a hard time extracting the generalized information that is usefull for an encyclopedia article. The field is very new and, at this point in time, it's mostly about gathering data. The overarching general conclusions that are bound to add so much to the theory of evolution are still in the future, but we might as well start building up this article.--Roland Deschain 18:31, 20 August 2006 (UTC)

I have added some more material. I think this article could be expanded even more, especially given the powerful ways evo-devo respondes to arguments of ID. Slrubenstein | Talk 17:15, 20 August 2006 (UTC)

I just finished reading the theories behind the evolution of the tool kit and will add that to the article as soon as I can find a way to make all the information intelligable to a casual reader.--Roland Deschain 18:31, 20 August 2006 (UTC)

I am glad you are working on it. I wouldn´t be surprised if some advocates of the theory are overly enthusiastic about its implications for models of evolution in general. However, that is not a reason for excluding those views from the article - we just need to be clear to identify what views are widely accepted by evolutionary scientists versus those views forwarded by respected scientists but which are nevertheless speculative or provisional. Roland, do you know of anyone else active here who could help (e.g. someone expert in both evolutionary theory and embriology)? I value your knowledge and appreciate your helping out but it would be easier if there were someone else to pitch in. Surely someone else here has read books or articles by Sean B. Carroll, Jennifer K. Grenier, Scott D. Weatherbee, John Gerhart or Marc Kirschner (for example)? Slrubenstein | Talk 20:35, 20 August 2006 (UTC)

I just finished Carroll's Endless forms. It would take some doing to digest for this article. I didnt know about his textbook. Although the article has two cites to it, neither has the year it was published. Can whoever referenced it please make the citation complete? Thanks alteripse 00:18, 21 August 2006 (UTC)

I put in the citation but my informatio is incomplete and I do not have access to a library. I am glad you have read the book. From reviews I have read it is important (whether or not everyone agrees with him) and I hope however long it takes you to digest it, you reacha point where you can draw on it to improve this article. Thanks, Slrubenstein | Talk 03:04, 21 August 2006 (UTC)

The book is cited twice now, but two different years 2004 and 2005 are given. Which is correct? alteripse 10:56, 21 August 2006 (UTC)

Mine is the second edition and is published in 2005. I included the ISBN number for anybody to check up on the exact version.--Roland Deschain 12:19, 21 August 2006 (UTC)

Problem of novelty

Evo-devo is a new field and there are many contending ideas for the origin of novelty. The sources cited on epigenetic and plasticity-based mechanisms provide different solutions for the problem than the one proposed by Carroll et al. It can hardly be claimed that the problem of novelty is "solved" by changes in regulatory genes. This doesn't explain the nature of the particular novelties that have emerged, which the other sources address. It's better to say "partly solved" or something equivalent.--StN 04:08, 25 August 2006 (UTC)

In general, it's better to wait for the explanation rather than reverting a change, particularly if it's a change that introduces a qualification of a strong assertion.--StN 04:12, 25 August 2006 (UTC)

The paradox that is solved is this: highly divergent organisms that look entirely different (fly and mouse) have the same developmental genes. This is solved by the finding that it is the regulation of these genes that affects the body plan, not their sequence. The actual question (note: not paradox) of how the actual genes affect all this novelty of biodiversity has not been answered. So I think we are thinking of two different things. The actual paradox I have outlined above has been answered (I will find another book that states it tomorrow if I can), but the question of how these genes and regulatory networks create novel bodyplans has not been answered. Note that there is no paradox in the origin of body plans. Rather, it is an open question that requires a lot more data before theories can be made.--Roland Deschain 04:20, 25 August 2006 (UTC)

I always make the change first then discuss. Draws people in faster. The book actually addresses that exact paradox and makes that statement. It is a strong assertion, but one that is well esteblished by now. As I said above, I will find a couple of other references to back it up, as I do see your point.--Roland Deschain 04:20, 25 August 2006 (UTC)

OK, here we go found a couple of sources that back up my statement:

• If you have a access to the journal Science read ( Jun 22, 2001.Vol.292, Iss. 5525; pg. 2256) entitled Resolving the Hox Paradox, here is a quote: "changes in transcriptional regulation as the most important locus of evolutionary rewiring". It's a good article and it mentions a couple of other books that support this claim. I will read this article tomorrow and update this page.--Roland Deschain 04:44, 25 August 2006 (UTC)

You might find other sources that back up Carroll et al.'s assertion, but that doesn't make it true. Why don't you look at the West-Eberhard book or the special issue on innovation and novelty in the Journal of Experimental Zoology, cited in the article, before concluding that the novelty problem has been solved? The problem of phenotypic novelty is not just a problem of gene change. As it stands, the article contains a contradiction, stating that novelty is partly due to epigenetic processes, but earlier, in the same section, that the problem has been solved by the recognition that regulatory genes have changed.--StN 04:48, 25 August 2006 (UTC)

Why don't you also check out "Evolution: Developmental Circuits Rewired" Nature. 2001 May 10;411(6834):143-4, 145. It describes how the gene changes discussed by Carroll may actually follow, rather than cause, evolutionary innovations.--StN 04:55, 25 August 2006 (UTC)

I changed the key word to make the sentance more neutral. I read the Nature paper a lot time ago and I don't remember anything to support your view point. Do you mind picking a couple of quotes like I did for the science paper above. I will provide 4 references by tomorrow that claim that the paradox has been addressed. When you say "You might find other sources that back up Carroll et al.'s assertion, but that doesn't make it true.": you should read WP:V. Wikipedia is not about truth, but rather about verifiable sources.--Roland Deschain 05:10, 25 August 2006 (UTC)

I can live with that change. I will rewrite that section soon to clearly differentiate the paradox brought up by Gerhart and Kirschner from the open questions in evo-devo (such as the mechanism behind the novelty of biodiversity, the various ways gene regulation is archived, etc etc).--Roland Deschain 05:20, 25 August 2006 (UTC)

Folks let me just point out that NPOV does not require us to delete controversial or even minotirty or challenged claims. It calls on us to provide multiple points of view, properly identifying and contextualizing each point of view, and, when possible and appropriate, characterizing it (all, most, many, some, a few). Doesn´t this mean that both views can be included in this article, being carful to distinguish between (1) what all agree on, (2) what some disagree strongly on, (3) what some have forwarded provisionally or speculatively as possible, and (5) what no one accepts?Slrubenstein | Talk 16:22, 25 August 2006 (UTC)

I entirely agree with the comments of SlRubenstein. (Please sign your comments.) I defintiely think all sourced views should be covered. If strong claims have been made that one or another discovery has "solved" a problem, it should be described as a claim, not a fact. Any legitimate source that disagrees with the claim should be mentioned, and its position summarized.--StN 16:16, 25 August 2006 (UTC)

Thanks. Since this is an emerging field I think it is likely that we will need a sectin on competing interpretations of the broader significance of the theory.Slrubenstein | Talk 16:23, 25 August 2006 (UTC)

Yeah, my wording was a little too strong ;). However, don't forget about Undue weight. If somebody can provide a majority of sources claiming that the problem is solved, then that view point should be given priority (the reason why creation science is almost never mentioned in science articles, as it's a very small minority with very little publications). I'll start gathering direct quotes that this problem is actually solved and put them in the article. Of course, everybody else can find opposing quotes. I do suggest that only direct quotes should be used rather than references, as references can be scewed and few people will go out and actually read a reference. --Roland Deschain 16:31, 25 August 2006 (UTC)

I found a nice quote that should be put in this section. It's from the Science paper above. It is a middle ground and I think reflect both sides fairly well: "Just a few years ago, the dominant research agenda was documenting the apparent conservation of regulatory gene function among distantly related taxa; now we know that the situation is considerably more complex. The clear challenge for the future lies in unraveling the genetic basis for anatomical diversity." I'll include it in the paper as soon as I have time. So this shows that the paradox of genetic conservation is fairly well behind us. Rather the new and far more exiting challange is figuring out how all this diversity came about.--Roland Deschain 20:43, 25 August 2006 (UTC)

Evolution of mechanism resulting in asymmetrical development

The following article is relevant to this discussion: A. Richard Palmer, Symmetry Breaking and the Evolution of Development, Science 29 October 2004 306: 828-833. From the abstract: "[D]irectional asymmetry, an evolutionary novelty, arose from nonheritable origins almost as often as from mutations, implying that genetic assimilation (‘‘phenotype precedes genotype’’) is a common mode of evolution".--StN 03:04, 26 August 2006 (UTC)

Journal hunting, my favorite past time. Note that this article is about a specific mechanism in the developmental process that causes asymmetry in the organism (ie: heart on the left side). So kidneys would be excluded from this article as they are symmetrical. Liver would fall within this discussion.

Here are a couple of more quotes that apply to this article (from the journal mentioned by StN:

• "But general hypotheses [in evo-devo] remain hard to test because organisms differ so much in form."
• "Informative insights should come most readily from traits that (i) are well defined and unburdened by troublesome semantics, (ii) are easy to compare anatomically and developmentally, and (iii) have evolved multiple times independently."
• "Left-right asymmetry offers a particularly attractive focus for comparative studies because of its binary-switch nature."
• "Left-right differences, therefore, arise becausesome kind of switch causes the mediolateral axis on one side to differ from the axis on the other side (4), although the mechanisms remain unclear for most organisms."
• "Conspicuous asymmetries have evolved independently in many animals and plants (6–8), so far-reaching generalizations are possible."

I'll stop here. This article is great in that it picks a specific simple step in the developmental process. It should fit quite nicely in the article as it is easily visualized by a non-scientist (the actual mechanism is like a switch, althought the molecular mechanism varies depending on the specific organism due to independant evolution of this step). In humans, it's a molecular propeller that spins and causes proteins/RNA to go into only one side of the organism.--Roland Deschain 03:49, 26 August 2006 (UTC)

---

Roland, Samsara, StN, I added the "expansion" tag. You guys have done a trtemendous amount of work and I only want to bring more contributors in. On the top of this page is a to do list. Can you guys review and revise it? Thanks, Slrubenstein | Talk 19:16, 28 August 2006 (UTC)

External links

Please don't keep putting back the external links to the special journal issues. they are now in the References.--StN 03:47, 29 August 2006 (UTC)

Ah, didn't see that. Delete them.--Roland Deschain 03:49, 29 August 2006 (UTC)

re:could be expanded on

I don´t know, but someone once thought there should be material relating evo-devo to functional genomics and comparative genomics. Was s/he right? Should this article have sections on these topics with links to these two articles?

The same person thought there should be more discussion on the relationship between morphology and the genome. Was s/he right?

I honestly do not know the answers to these questions and am not making any argument, just asking people who have recently been working on the article (and who are thus more knowledgable than I) whether these suggestions are appropriate and constructive.Slrubenstein | Talk 04:45, 29 August 2006 (UTC)

References and notes

Something is going wrong with the notes. Each time I return to the article they are in a different order, apparently not due to anyone's new edits. For example, the last time I looked Monod was promoted to Note 1, event though Hall is the first cited. The first superscript to appear in the article is now [2], referring to Hall, when it should be [1], referring to Hall. Monod is listed in the notes as if it has been cited twice (ab), which it hasn't. I believe all the citations have been entered correctly; if someone knows how to fix this, please do so.--StN 05:04, 29 August 2006 (UTC)

I removed the Hall citation and then replaced it. Now everything is in the correct order, but all the notes are now listed as cited twice.--StN 05:09, 29 August 2006 (UTC)

Fixed it, for the time being. There was an extra space in one term in the notes syntax box. Perhaps that was it.--StN 05:14, 29 August 2006 (UTC)

There seem to be several different styles in use for the notes. Can I suggest the following:

• inline citations where only one place in a source is referenced, so that it appears in the notes section.
• harvnb template for those references where, in different places in the article, different pages or sections are referred too, so that the individual page references appear in the notes section, and the main entry appears in the reference section.

Ernestfax^Talk 00:21, 24 July 2010 (UTC)

Drosophila image

The image shown was taken from a publication of a U.S. government agency (NASA), but it is not the logo of NASA or any other government agency, as stated in the license box. In fact, it is credited to the Scientist magazine in the original NASA article. It therefore does not come under open source or fair use provisions required for publication in Wikipedia. It is a nice picture, but it will have to be removed unless an appropriate use justification can be obtained.--StN 16:58, 2 September 2006 (UTC)(posted on September 1)

The image has been deleted pending a better justification for its use.-StN 16:58, 2 September 2006 (UTC)

Recent revisions

The genes-acting-as-switches, Jacob-Monod model, is ancient history in molecular biology that had been incorporated into eukaryotic developmental biology by the 1970s. It doesn't have that much to do with evo-devo. The surprise in the discovery of the Hox genes and the rest of the developmental-genetic toolkit was their conservation, not the fact that they act as switches. The evo-devo-related research that followed was on how the same regulatory proteins could be involved in such different patterns of embryogenesis. This involved findings of promoter sequence evolution, plasticity, etc. I have streamlined the discussion to reflect this, and made other edits that removed redundancy and improved the logic and readability of the article.--StN 02:35, 4 September 2006 (UTC)

My basis for these claims was a NYRB article written in part by Edward Ziff, Professor of Biochemistry at the NYU School of Medicine. I think this is enough reason to include the point that at least some people believe the idea of switch is important. NPOV requires representing multiple views. I do not object to your adding a different view. Nor do I object to your characterizing Ziff´s view as a minority. But I do object to your removing it altogether. Slrubenstein | Talk 02:59, 4 September 2006 (UTC)

I agree with Slrubenstein. The idea of genes-acting-as-switches is an old idea, but today it is even more prevalent than it was in the day of it's conception (got them a Nobel Prize). It is a concept that is found throughout the field of evo-devo and should definetly be mentioned in this article. Rather than taking a back seat it should be explained more carefully, maybe in the history section. The Jacob-Monod model goes way beyond just switches; it is the first indication that genes act not just code for machines (enzymes) but also code for the whole regulatory network of the organisms. This regulatory network is currently one of the biggest questions in evo-devo and some of the history should be reflected in this article.--Roland Deschain 03:06, 4 September 2006 (UTC)

The NYRB is not a scientific journal. I read this article and found it quite superficial, dipping back into the history of molecular biology to explain evo-devo to non-biologists (a worthy objective, similar to the objectives of the present article) but on the basis of concepts that had already been incorporated into conventional developmental biology. Edward Ziff is indeed a reputable molecular biologist, but I do not think he has worked in evo-devo, and the other author, Israel Rosenfeld, is not a biologist. You could put back the Jacob-Monod 1961 switch stuff, but in my view it should be supported by citations to Carroll's or Kirschner and Gerhart's books, not the NYRB. I personally think it is irrelevant to evo-devo, however. There are many eukaryotic transcription factors (gene products that act as switches) that have nothing to do with development. And it was the *conservation* of the Hox-class switches, not the existence of developmental switches, that spurred evo-devo.--StN 03:20, 4 September 2006 (UTC)

StN I appreciate all the work you are putting into this but with all due respect, "I personally think it is irrelevant" is precisely why we have an NPOV policy. What we editors think is just irrelevant. What is important is representing different points of view with verifiable sources. Ziff´s views meet that mark. As I said I am not claiming it is a mainstream or dominant view, only that it ought to be included, given our own policies. Roland, will you make the appropriate changes? You know more than I do and since you agree with me, and have done much research on this, I trust you can put the Jacob Monod and switch stuff back in in a way that will satisfy me and StN. Slrubenstein | Talk 03:31, 4 September 2006 (UTC)

I agree that my personal views are not relevant. I was just trying to indicate that it would be logically difficult, in the framework of this article, to show why the switch aspect of Hox genes implies a new view of evolution. The fact that Hox proteins control other genes is entirely consistent with the pre-evo-devo modern synthesis. It was only the recognition that the protein-coding portions of Hoxs, Paxs, etc. were not too relevant to their developmental role that led people to begin considering that it was changes in regulation via promoter evolution, not protein content, that was the important thing (i.e., what Carroll is referring to as "cis-regulatory systems.." in the quote we use). If you can put back the switch idea in a way that shows its relevance to evolutionary theory, in a fashion sourced by the biology literature, please do so.--StN 03:45, 4 September 2006 (UTC)

I have been thinking about the genes as switches question and I think there is a rationale for putting back a mention of the Jacob-Changeux-Monod paper and the idea that some gene products control genes. There are actually two different takes on the history of evo-devo. One school ("genetic determinists" -- Carroll, Davidson, Kirschner, Gerhart) sees continuity with the modern synthesis, with everything due to genetic change, and evo-devo just representing the consequence of bringing modern developmental biology (gene products acting as switches and diffusible morphogens) into evolutionary theory. The other school ("epigeneticists" -- West-Eberhard, Newman, Müller, Palmer) focuses on the plasticity of development and the notion that genetic change can follow phenotypic change. This more radical idea represents a real challenge to the modern synthesis. In this formulation, putting back the gene products as switches idea, and even a citation to Rosenfeld and Ziff as a representative of the view of evo-devo as the modern synthesis + developmental mechanisms, would work very well. Of course the first paragraph of the Introduction section, as currently written, only reflects this one view.--StN 21:07, 4 September 2006 (UTC)

I put back swtitches (and added morphogens).--StN 21:59, 4 September 2006 (UTC)

Thanks! (also, I didn{t mean to accuse you of violating policy. but put it another way: on-specialists will read this article. I think it is important not only to write based on expert knowledge in an accessible way, I think it is also important to address current popular ideas. If some of these ideas are simply wrong it can be education to explain where exactly the misperception is. Or some of these ideas may just reflect the fact that some people (readers of the NYRB for example) are not always interested in the same things readers of technical peer-reviewed journals are. But we should address their interests - and use this as a teaching moment to explain why molecular geneticisms and embryologists are actually interested in other things. Finally, some views may not be wrong but may be just highly speculative. Again, we should include them and just explain what the speculation is and just how speculative it is). Slrubenstein | Talk 23:38, 4 September 2006 (UTC)

I agree that Jacob-Monod switch idea is worthy of mention. The switches concept could also be evoked in West-Eberhard's theory of develpmental phenotypic plasticity. She mentions the idea of developmental switches as responding to nature in creative ways and they are plasticity induced focal points. Modularity has become a fundamental aspect of evodev. We need a section on modularity and then a counter view. Are any of you familiar with- The Development of Animal Form :Ontogeny, Morpholog, and Evolution by Alessandro Minelli? He makes some powerful arguments against modulaity that maybe shoulc be entertained for NPOV purposes? GetAgrippa 14:49, 5 September 2006 (UTC)

Sounds good to me! Slrubenstein | Talk 20:53, 5 September 2006 (UTC)

Evodevo Research

I plan to add some evodevo research on jaw and ossicle homolgy, gills and parathyroid and ultimobranchial bodies, calcium sensing receptors, evodevo in plants, wing patterns in butterflies, eyes,segmentation in lower animals and mammals, and fish like sticklebacks. I hope to accomplish this in the next month and may or may not include all the aforementioned.GetAgrippa 15:18, 4 September 2006 (UTC) Maybe I should divide this into groups. Patterning and segmentation using plants, insect, fish, and mammals. The economy of genes and gene networks in evolution of organs (such as eye, parathyroid glands, etc.), and tissues (gene homologues used in various tissues with similar function-huge number of examples). Genes and gene networks in speciation. I'll develop it and wait for critiques to develop a finished product. I don't want it to be grandiose, but it should give the subject some attention.GetAgrippa 15:37, 4 September 2006 (UTC)

This sounds great. Any opinion on the "switch" issue?--StN

I have been gathering research articles and I really have too much. I will start writing soon and then condense it to the gems.GetAgrippa 20:19, 8 September 2006 (UTC)

Can´t wait!! Slrubenstein | Talk 20:00, 11 September 2006 (UTC)

I have made some progress at writing on the issues I think should be in this article, but upon further reflection I have decided not to directly contribute to articles. I have come to the belief that expertise is a hindrance in writing simple, balanced, and informative articles suitable for an encyclopedia. I tend to agree with AdamRetchless. I will offer suggestions for editing on talk pages, but no longer add directly to articles. I apologize for abandoning the effort. I have been excited about contributing to the evodevo article and embryology, but now realize that my effort is probably too complicated and specific for an encyclopedia.GetAgrippa 21:50, 13 September 2006 (UTC)

I beg you to reconsider. My suggestion: pick one or two specific areas of evo-devo research and make sure theya re well-represented in the article; conversely, choose one or two themes of the article and make sur ethey are current and accurate. I think by thus narrowing your focus you will be able to make very valuable contributions. Slrubenstein | Talk 04:10, 14 September 2006 (UTC)

I actually disagree profoundly with AdamRetchless on the role of expert editors. I think "guiding" lay editors creates just the kind of hierarchical structure here we want to avoid. Of course, everyone knows something, and each person active here is qualified to give advice or make suggestions to most anyone else. This is part of a collaborative process, not a hierarchical structure. I think all editors should view themselves and one another as equals in the sense that they must all comply with our core principles (e.g. NPOV, NOR, Verifiability), and if they do, their contributions are all valid. These policies are the great equalizers. They change an expert editor from someone with the authority to cast forth knowledge ex cathedra to just another person who happens to know a lot of stuff. And this is indeed the kind of person we need more of, actively editing articles. Slrubenstein | Talk 11:50, 26 September 2006 (UTC)

Some feedback

The article as it stands is a bit on the technical side and a little vague on what exactly evo-devo is. I would like to suggest a refactor and reorganization of this text; the result should have a more clear emphasis on how changes in gene expression during development can help drive evolution by resulting in disproportionate effects on morphology and function of the organism (that is, a small genetic change that alters development can have a large effect on how the adult looks and works). That is what this article is about, no? Some space should also be set-aside to explain these concepts and how they relate to evo-devo:

• Heterochrony - Study of the changes in developmental timing that result in different morphology of the adult (that topic is so highly related, that that article may need to be merged here)
  • Neoteny/Pedomorphosis - The retention of larval traits in an adult (the overall juvenile/tadpole characteristics of the salamander are an example)
  • Allometric growth - How differing growth rates of body parts can greatly change the adult size of those parts (classic example is the near fetal shape of the adult human skull).
• Preadaptation/evolutionary plasticity - Also worth mention (and possibly a great way to tie this back into macroevolution), is how evo-devo acts to modify existing features in such a way that natural selection can find other/novel uses for those features (stressing that evolution is not goal-oriented)

On a general note: One distressing thing I've noticed, is the tendency of Wikipedians to create articles on nearly every term one would find in a biology textbook. Many of these terms, such as Neoteny and Pedomorphosis mean pretty much the same thing while others, such as evo-devo and Heterochrony are so closely related that it is a disservice to the reader to separate the two; much better to explain the two concepts and how they relate in the same space. Only when the synthesis article becomes too big for its own good, should individual articles be created on sub-topics (allowing the synthesis article to get back on its main topic). What we currently have is a confusing mess of highly related almost stub articles. In short - We need to enforce the concept that an article is not necessarily needed just because a term exists. --mav 02:08, 1 November 2006 (UTC)

concerning the trend to microevolution

This is a comment for GetAgrippa and StN. I wonder whether the question of whether there is a trend away from macroevolution to microevolution or not may actually disguise a different issue. I raise this because if I am right it becomes a topic that both of you can work on together rather than disagree over. Here is what I am thinking: what appears to be a trend may actually be a phase, and the real issue may not be microevolution versus macroevolution but rather the way scientists often oscilate between long periods of collecting data and long periods of building abstract models and speculating about theory. (I am also assuming that micro- and macro-evolution refer not only to different scales of change in allele frequencies, they also refer to different methods of research and very different kinds of outputs.) I suspect many scientists reach a point where they get tired of compiling data from assays or repeated experiments or field observations and put time into an article or book that tries to synthesize and push the limits of theory - or, conversely, when scientists get tired of playing around with abstract models and yearn to return to the field. Or, some scientists are just better at one task and others better at the other, although their publication cycle may be out of sync. Or, scientists respond to changing funding opportunities. Any of these could mean that what appears to be a trend isn't really. But my point is not to challenge GetAgrippa's edit. My point is that it may be much more illuminating to write about the relationship between careful documentation of the kind of data that can be collected over a short period of time through empirical observation and experiments, and attempts to generalize and synthesize and relate such data to theoretical models. My guess is that evo-devo is "young" enough that the one thing that most researchers can agree on is that so far findings are intriguing and even exciting but much more work needs to be done. It wouldn't surprise me if right now there aren't a host of post-docs who are doing all sorts of research, trying to further our knowledge from different angles, using different methods, and who are not ready yet to publish. Wouldn't this article be more educational if instead of making claims about the trend in terms of the scale of research, the article explained to readers why scientists need to work at different scales, and the recursive relationship between field or experimental data and "big" theories? Slrubenstein | Talk 15:03, 17 December 2006 (UTC)

I basically agree with Slrubenstein. In my view evo-devo has come into prominence because of neo-Darwinism's failures vis-a-vis macroevolution; it does ok with microevolution. I think my edit of GetAgrippa's recent addition yields a more accurate characterization of the field, but the interest by evo-devo researchers in microevolution still needs documentation, and as Slrubenstein says, some statement about its theoretical motivation.--StN 19:00, 17 December 2006 (UTC)

Thanks - I was afraid I was coming of as naive. But if GetAgrippa agrees with you, perhaps both of you could discuss what a section on the relationship between research at the level of microevolution and macroevolution, or the relationship between field studies and laboratory research on the one hand and theory - which both guides research and is revised in light of research - might look like. Slrubenstein | Talk 10:33, 18 December 2006 (UTC)

While I am at it, I know Mav's comments above were made in good faith and they seem reasonable to me but I am not expert enough to act on them. Do StN and GetAgrippa agree these were constructive suggestions? if so, can you two work out a way to act on them? Slrubenstein | Talk 10:33, 18 December 2006 (UTC)

D'Arcy Thompson

Would expect a mention of him in the (pre-molecular) history of the subject.

Wallace Arthur (2006) "D'Arcy Thompson and the theory of transformations", Nature Review Genetics p401

— 10.1038/nrg1835. Summary: Understanding how developmental processes are altered evolutionarily to produce changes in organismal form is one of the great challenges of evo-devo research. D'Arcy Wentworth Thompson deserves much credit for the inspiration his work has provided for modern evo-devo., [1]

Shyamal 03:52, 25 May 2007 (UTC)

Sure, except I think the real scandal at Wikipedia (one of them) is that the article on Embryology - the larger field, and a major field of biology - is woefully under-developed. If you wish to start an article improvement drive on embryology let me know and I will endorse it! Slrubenstein | Talk 15:47, 12 November 2008 (UTC)

An excellent BBC Channel 4 program

An excellent BBC Channel 4 program on epigenic transgenerational research discoveries is found at http://video.stumbleupon.com/#p=yes9e6lz9v. John D. Croft (talk) 11:00, 12 November 2008 (UTC)

more feedback

I attempted to edit the third paragraph because I was disturbed that genes and gene networks were considered "processes". This is factually incorrect. They are not processes, they are genes and gene networks. While attempting this, I noticed that in this paragraph limits the scope of evo-devo to just genes and gene networks. Perhaps it would simply be easiest to remove these parenthetical statements as they are grammatically and conceptually incorrect and seem overly restrictive in scope. I set out to do this, then noticed the lively debate here. I'll leave it to you all, but did want to leave my comment on the section. Imnotamouse (talk) 19:33, 10 February 2011 (UTC)

Lively, but old and apparently forgotten. So please hop in and improve. Certainly, genes are not processes. But isn't it the case that evolution changes processes by changing genes? --Ettrig (talk) 03:57, 11 February 2011 (UTC)

Images would be great

This article could use some photos and diagrams to help illustrate key concepts.--Animalparty-- (talk) 19:28, 6 January 2014 (UTC)

Inappropriate speculation in introduction

The last sentence of the current introduction - " Another possibility is the Neo-Lamarckian theory that epigenetic changes are later consolidated at gene level, something that may have been important early in the history of multicellular life." - looks too speculative to be in an introduction (it even admits this by using the word "possibility"). The introduction is not the place for rather off-beat speculation. The notion of epigenetic changes causing genetic changes that have a similar effect is indeed not an established result - there is a purely Darwinian explanation of Waddington's (ancient) experiments and a striking lack of more recent improvements (https://en.wikipedia.org/wiki/Genetic_assimilation#A_Darwinian_explanation). The idea would require a lot of evidence since there is no way for the genome to "know" what genetic changes would produce the given effect, so the only real way to achieve it is by mutation and natural selection.Elroch (talk) 12:33, 2 November 2021 (UTC)

Thanks for your thoughts. However, the lead is purely a summary of the cited text in the article body, and the sentence you mention does correctly summarize part of the 'origins of novelty' section. Since scientists have explored the mechanism, and the article describes it, it's fine for the lead to mention it briefly, as it does. Chiswick Chap (talk) 13:16, 2 November 2021 (UTC)

Lead is short

According to Wikipedia:Manual of Style/Lead section, the lead is to contain an overview of the article content. The lead in this article is too short. --Ettrig (talk) 13:06, 18 October 2016 (UTC)

Yes, of course. I had been waiting until the main sections were written before attempting to summarize them. I have added a summary now. Chiswick Chap (talk) 13:18, 19 October 2016 (UTC)

• Just a tiny remark to the lead. The sentence "Another is that species do not differ much in their structural genes, such as enzymes; ..." should be changed to something like "Another is that species do not differ much in their structural genes, such as those coding for enzymes; ..." to be more correct. Sf66 (talk) 19:05, 16 November 2016 (UTC)

Well spotted. Chiswick Chap (talk) 19:08, 16 November 2016 (UTC)

History in non-history chapter

The article has a history chapter that is a large percentage of the article. Historical content, like

Many of these organisms share the same structural genes for body-building proteins like collagen and enzymes, but biologists had expected that each group of animals would have its own rules of development. The surprise of evo-devo is that the shaping of bodies is controlled by a rather small percentage of genes, and that these regulatory genes are ancient, shared by all animals.

and

The puzzle of how embryonic development was controlled began to be solved using the fruit fly Drosophila melanogaster as a model organism. The step-by-step control of its embryogenesis was visualized by attaching fluorescent dyes of different colours to specific types of protein made by genes expressed in the embryo. A dye such as green fluorescent protein, originally from a jellyfish, was typically attached to an antibody specific to a fruit fly protein, forming a precise indicator of where and when that protein appeared in the living embryo. The pax-6 gene controls development of eyes of different types across the animal kingdom. Using such a technique, in 1994 Walter Gehring found that the pax-6 gene, vital for forming the eyes of fruit flies, exactly matches an eye-forming gene in mice and humans. The same gene was quickly found in many other groups of animals, such as squid, a cephalopod mollusc. Biologists including Ernst Mayr had believed that eyes had arisen in the animal kingdom at least 40 times, as the anatomy of different types of eye varies widely.

Should be put in that (history) chapter. --Ettrig (talk) 13:18, 18 October 2016 (UTC)

Thank you. Of course, everything we write and cite is history, we can't write articles about the future or even the present. I thought it necessary to set this (from one perspective) very new field in the context of 200 years of history; and from another perspective, to attempt to separate out some of the richly interwoven strands like Deep Homology to help readers navigate around what is quite a complex story - to give them structure and points of reference. Obviously, when covering a field from different points of view, some of the material can always be presented in different ways, whether "History" or as "topics", it's a matter of judgement. There can't be any "right answer" here. But if I were to pull out the materials you mention from the Deep Homology section, there would be almost nothing left; or we'd create a large amount of overlap, and we all try hard to avoid repetition. So rather than think of it as a "non-history chapter", whatever that might be, just think of it as varying the focus, or pointing the spotlight in specific directions to light up one player on the stage at a time. Chiswick Chap (talk) 15:46, 18 October 2016 (UTC)

You explain the problem very well. Yes, it is a complex story. Complex organisms are built by complex machineries. Those complex machineries are modified successively. We need to have a picture of how the machinery is defined (genes) and how it works, as a background to descriptions of what happens when it changes. But this text almost doesn't start to describe this. Instead it is filled with historical anectdotes. If these anecdotes are moved to where they belong, then there is "almost nothing left". Exactly! There is very little about the basic substance of the topic. This becomes clear when the statements are sorted under the correct headlines. I don't mean to complain. This is a nice text. I am just pointing out adjustments that are needed to arrive at a Good Article state. --Ettrig (talk) 17:47, 18 October 2016 (UTC)

Thank you, but I don't agree at all. There are no anecdotes at all, only cited and reliably sourced evidence. What I am explaining is that the article looks at the subject from different perspectives. It covers the material, but it would only repeat itself (worded differently) if we put everything into first a historical format, then a topic format. Chiswick Chap (talk) 19:05, 18 October 2016 (UTC)

Yes, evidently we differ on such a fundamental point as whether the content can and should be divided into the categories that the headlines define. I think it can and should. To me this is so fundamental that it is very difficult to find any values that are even more fundamental and can be used to motivate this principle. For the time being, I hope for a reaction from the GA reviewer. --Ettrig (talk) 05:48, 19 October 2016 (UTC)

What is fundamentally wrong about describing a topic with its history and its major subtopics? One might have thought that was a necessity for any article. Chiswick Chap (talk) 06:20, 19 October 2016 (UTC)