Wikipedia:Peer review/Hershey–Chase experiment/archive1

Hershey–Chase experiment

This peer review discussion has been closed.
I've listed this article for peer review because we are trying to gain insight into how the article could be formatted better for use on WIkipedia.

Thanks, Jmn49114 (talk) 19:17, 1 April 2011 (UTC)

Ruhrfisch comments: Thanks for your work on this article - it looks pretty good, especially for some of your first work here, but as you already know it is not yet ready for FAC. I also think it needs some work before it will pass at WP:GAN, so here are some suggestions for improvement with GAN in mind, and FAC eventually.

• I corrected one error - the article lead used to read "Hershey shared the 1969 Nobel Prize in Physiology or Medicine with Chase for their “discoveries concerning the genetic structure of viruses.”[2]" but Hershey shared the prize that year with Delbrück and Luria, and Chase never received any part of a Nobel Prize.
• I would treat the FAC as another review - I would look at every point raised there and address it too.
• There is one disambiguation link, to polymorphism, which needs to be fixed - see toolbox on this page.
• Looking at WP:LEAD the lead is not supposed to be more than four paragraphs long, but this is five.
• The lead should be an accessible and inviting overview of the whole article. As such, nothing important should be in the lead only - since it is a summary, it should all be repeated in the body of the article itself.
• My rule of thumb is to include every header in the lead in some way - the current lead does not include Applications or the Arsenic-based life forms, for example.
• The main problem with the article right now is a lack of references. The whole Predictions section has no (zero) refs, and some whole paragraphs (such as one in Crime investigation) have no refs, but need them. My rule of thumb is that every quote, every statistic, every extraordinary claim and every paragraph needs a ref. If a paragraph ends without a ref, that raises a flag for many reviewers.
• Make sure that all refs have all needed information. Internet refs need URL, title, author if known, publisher and date accessed. {{cite web}} and other cite templates may be helpful. See WP:CITE and WP:V
• Things have to be consistent too - so it can't be "Proc. N. A. S." in one ref and " Proc. Nat. Sci. USA" in another ref. I would spell out the full names of references anyway.
• I have serious concerns that this article is engaing in either synthesis or original research, neither of which is allowed in Wikipedia articles. Hershey and Chase used radioactive tracers, which are not used much anymore. For example, looking at the section on Arsenic-based life forms, there is no mention of either Hershey or Chase in either of the sources used as a reference in this section. Without a ref that says it, this article should not make statements like While controversial, the research demonstrated scientific and experimental principles of hereditary analysis relevant and similar to the Hershey-Chase Experiment. Wikipedia articles follow what the sources say, and if no sources say this directly, this article can't say it either. Do textbooks say anything about the relevance of this experiment to later work in the field?
• Similarly, both of the techniques described in Applications seems like something of a stretch to relate directly to this (again the radiotracer techniques Hershey and Chase used are quite different from PCR or other modern genetic techniques, and I do not think either uses phages much if at all). I think it is OK to say that this experiment helped set the stage for these techniques, but to go into so much detail is also a WP:WEIGHT issue, unless there are sources that make the explicit points made here.
• I would make the lead image larger for better clarity.
• Please make sure that the existing text includes no copyright violations, plagiarism, or close paraphrasing. For more information on this please see Wikipedia:Wikipedia_Signpost/2009-04-13/Dispatches. (This is a general warning given in all peer reviews, in view of previous problems that have risen over copyvios.)

Hope this helps. If my comments are useful, please consider peer reviewing an article, especially one at Wikipedia:Peer review/backlog (which is how I found this article). I do not watch peer reviews, so if you have questions or comments, please contact me on my talk page. Yours, Ruhrfisch _><>°^° 03:36, 8 April 2011 (UTC)

Comment I noticed this article in the GAN queue. I'd be happy to review, once the peer review is completed and the points above are addressed. I have several years of experience with advanced microbial genetics, and some FAC experience, so would be happy to help push towards FA, if that's the goal. Ping me if interested. Sasata (talk) 15:43, 11 April 2011 (UTC)

Graham Colm comments: I agree with the comments above, so I will try not to repeat them. My main concern is the Applications section. None of these are applications of the experiment; they don't use bacteriophages or blenders, or even bacteria. The experiment has no modern day applications really. It was important to the proof that DNA as the hereditary material—but that's all.(Most scientists had already accepted that DNA was the hereditary material following the meticulous work of Avery, which was published in 1944.) The section on arsenic-based DNA is interesting, but it does not belong in this article. I would resist the temptation to exaggerate the impact of the results of the experiment in an attempt to make the article longer and engaging. Short, accurate, neutral articles are OK. I have just checked my books—they all only devote one or two pages to this subject. Graham Colm (talk) 09:23, 16 April 2011 (UTC)

UM BIOE120 Instructor comments: I agree with most of the comments above. In addition, consider the following:

• It is necessary to mention that the H-C experiment was not perfect (e.g. see http://dx.doi.org/10.1016/j.virol.2005.09.014), and I am glad that the article has now been edited to that effect.
• Did H and C provide evidence that DNA carries the genetic code? Genetic information, yes, but the code was revealed many years later. Check your sources and reword this appropriately.
• Mention the tetranucleotide theory of DNA (prevalent in the earlier part of the 20th century, now abandoned) in the context of the debate that Hershey and Chase were trying to resolve. A good place would be in the Historical background paragraph, right after the word "... the molecule that could carry all the information for such a large amount of traits would have to be as complex".
• Organism names such as Escherichia coli have to italicized and be spelt out in full at first mention. I don't think you need to mention "E(scherichia) coli bacteria" -- just wikify the word Escherichia coli.
• Despite Graham Colm's integration edits, I think that "Hypothesis(es)" (as opposed to "Predictions") should be a separate section.
• The graphics accompanying the article are informative, but better-looking, high-resolution graphics (preferably in a vector format such as SVG) will really enhance your article. **The lead figure can be made more eye-appealing by adding color (different colors to indicate phosphorus and sulfur, different shades to indicate radioactive and non-radioactive). The only difficult thing would be to draw the virus, but give it a try.
  • The hypotheses tested by H and C could be nicely incorporated into the lead figure. Depict the predictions stemming from the two conflicting hypothesis, and highlight what was observed. Such a figure will summarize a large part of the article. Alternatively you could use a succinct figure (without hypotheses/predictions) in the lead and a more detailed figure to accompany the hypotheses section.
  • If you make a really good figure you can also nominate it for a Wikipedia featured picture.
  • The bacteriophage figure (although peripheral to this article), is an SVG and of high quality so I suggest retaining it.
• The sentence "They showed that, in growth, protein has no function, while DNA has some function" seems a little convoluted and is not making sense to me. Check your source and rewrite it.
• I agree with Graham's deletion of the "applications" of the result of the H-C experiments. However, you could bring back a little of that material and work it into the introduction and/or the conclusion. (For instance, The H-C experiments, its predecessors and successors served to unequivocally establish that hereditary information was carried by DNA. This finding now has numerous applications in forensics, crime investigation and genealogy [wikify these words]. You may use my suggested sentences verbatim. Add up to one more sentence to explain how this finding is applied in these fields and wrap up.
• A previous version of your article contained the phrase "[DNA] varies for each individual person while proteins contain the exact same sequences of amino acids for everyone". FYI, this is not accurate. If there is variation in the DNA that codes for a protein, there will be variation in the protein. Of course, DNA happens to have large regions that do not code for proteins, and even these contain mutations.

UM BIOE120 Instructor (talk) 01:20, 25 April 2011 (UTC)