Talk:Genetics

Template:WP1.0

Definition of Gene

Current statement describes:

Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides—the sequence of these nucleotides is the genetic information organisms inherit.

This definition seems to be rather for a locus. Truly inheritable material comprise rather alleles which carry individual genetic differences. So what is a gene? The current consensus does not give a clear definition. This is because the term gene was given for a theoretical entity. The reality, revealed later, was much more complicated than the theory and a gene turned out not simply a stretch of DNA. Since clear and adequate definition cannot be given in any way, the idea of locus and allele should also be shown with the very ambiguous and vague term gene.

Comments on images

Morgan's historical diagram of fruit-fly sex-linked genes was changed [1] to a more modern info-dense diagram that I find harder to read — since this is in the historical section, I think preference should be given to the historical image. But because I don't want to "own" the page, I'll just leave my comment here -- if anyone agrees with me, please go ahead and change it back.

The header DNA picture was also changed to something "more pretty" [2] ... I had chosen the one I did because this prettier picture has been criticized as being inaccurate (DNA does not actually have those two spiraling rods on either side). However, since this is also the lead image to the DNA article, it's obviously not a big deal. -- Madeleine ✉ ✍ 16:49, 12 March 2008 (UTC)

I would agree with both of these comments, but I am no expert. But I do favor simpler diagrams if at all possible, at least in overview articles. If there is a reason to put a more information dense figure in Wikipedia, put it in one of the subsiduary daughter articles that can accommodate more advanced topics.--Filll (talk) 14:48, 13 March 2008 (UTC)

Good Article review

• Can some of the images go to the left?
• Could you mention the high mutation rates in RNA replication compared to DNA.

This article is close to FA and this was one of the easiest GAs I've done. Another Wikipedia treasure. I loved the images. Well done.--GrahamColm^Talk 13:29, 13 March 2008 (UTC)

Thank you! I guess I should have done this a long time ago.  :)

About the images, I guess I was worried about ending up with "sandwiched" text. I've moved some images to the left now, people can move them back or around or whatever as they please ... I'll read up on RNA replication and figure out how to add it. Thanks! Madeleine ✉ ✍ 15:00, 13 March 2008 (UTC)

...did you mean transcription? Madeleine ✉ ✍ 20:12, 13 March 2008 (UTC)

Hi Madeleine, no I was thinking about viruses, RNA viruses. They are highly mutable because RNA polymerases do not have the 3' and 5' error correcting, (proof-reading), exo and endonucleases. Hence the high mutaion rate in HIV for example. I recall, but must check, that the error rate in RNA replication is about one base in every 10,000, whereas in DNA the error rate is one in around ten million. I just thought that an FA ready article on genetics should have a couple of sentences about this. Best wishes. Graham. --GrahamColm^Talk 20:43, 13 March 2008 (UTC)

Well... HIV is a retrovirus, so that's going to be the error rates for Reverse Transcriptase and transcription combined. There are also RNA-dependent RNA polymerases, used by polio virus. It looks like the error rate for RDRPs is basically the same as DNA polymerase without proofreading exonuclease, 10e-4 to 10e-5. (from: [3], search on "error rate") Reverse transcriptase and RNA polymerase also seem to have this error rate. Maybe a general comment on proofreading would be good, and then an aside saying "many viruses use DNA and RNA polymerases that lack proofreading and consequently have increased mutation rates". Madeleine ✉ ✍ 21:12, 13 March 2008 (UTC)

Yes, you've got it, but it's only really RNA viral polymerases, that lack the proofreading. Herpes (DNA) viruses are relatively stable and ancient. HIV, Hepatitis C virus are rampantly mutable RNA viruses. (But don't put this in the article - no need). Incidently, the Taq DNA polymerase used in PCR also does not proofread, which is why DNA base sequencing results need to be confirmed. (Again don't put this in). The article just needs a bit about proof-reading and RNA viruses. You should consider nominating Genetics for Featured Article. It still needs a little work, but it is closer than many that are currently in the queue, (?can't spell that?). Also as you are clearly and expert geneticist, I suggest a PubMed search on Reanney D. RNA (fascinating stuff about segmented genomes, errors, genetic noise and so forth) -. Graham. --GrahamColm^Talk 21:43, 13 March 2008 (UTC)

AIUI, there's also reverse transcribing viruses with a DNA genome? So I think it's best to just leave it as "many viruses". I'll definitely move towards nominating this for FA, it's really encouraging to have such a positive review. Many thanks! Madeleine ✉ ✍ 23:14, 13 March 2008 (UTC)

Yes of course, Hepatitis B virus is an RT virus with a DNA genome. :)--GrahamColm^Talk 11:03, 14 March 2008 (UTC)

WP:MOS issues

Thanks for the quick attention to the MoS issues; this is a bigger one. See Wikipedia:MOS#Italics, specifically the "words as words" section. This article has a pervasive overuse of quotes for "words as words"; most of the quotes aren't needed, some of them should be italics, all need to be fixed. SandyGeorgia (Talk) 03:54, 20 March 2008 (UTC)

Inconsistency in accessdates: is the article using Retrived on or accessed? Is it linking dates or is it not? Most use Retrieved on, some say accessed. Most dates are linked, a few or not. Some use full dates, some use ISO. See crit 2c, consistent citation style, samples:

^ Lamarck, Jean-Baptiste. (2008). In Encyclopædia Britannica. Retrieved March 16, 2008, from Encyclopædia Britannica Online: http://www.search.eb.com/eb/article-273180

^ genetics, n., Oxford English Dictionary, 3rd ed. Accessed 2008-03-16.

MANY URL's in the article have no last access date. SandyGeorgia (Talk) 04:09, 20 March 2008 (UTC)

Thanks for the review! It's late here; I'll work on fixing the citations tomorrow. Madeleine ✉ ✍ 04:12, 20 March 2008 (UTC)

no hurry, I've got more :-))

This is awkward and clunky, makes editing hard, and slows down load time, example:

^ a b A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. Chapter 3 (Chromosomal Basis of Heredity): Mendelian genetics in eukaryotic life cycles

^ A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. Chapter 2 (Patterns of Inheritance): Sex chromosomes and sex-linked inheritance

^ A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. Chapter 7 (Gene Transfer in Bacteria and Their Viruses): Bacterial conjugation

^ A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. Chapter 7 (Gene Transfer in Bacteria and Their Viruses): Bacterial transformation

^ A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. Chapter 5 (Basic Eukaryotic Chromosome Mapping): Nature of crossing-over

^ A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. Chapter 5 (Basic Eukaryotic Chromosome Mapping): Linkage maps

You can significantly improve the editability of the article and the readability of the sources by listing the basic info on the book once at the top of the References section:

A.J.F. Griffiths, J.H. Miller, D.T. Suzuki, R.C. Lewontin, and W.M. Gelbart (2000). An Introduction to Genetic Analysis. W.H. Freeman and Company. ISBN 0-7167-3520-2.

and then shortening every footnote thusly:

^ a b Griffiths et al (2000), Chapter 3 (Chromosomal Basis of Heredity): Mendelian genetics in eukaryotic life cycles

^ Griffiths et al (2000), Chapter 2 (Patterns of Inheritance): Sex chromosomes and sex-linked inheritance

^ Griffiths et al (2000), Chapter 7 (Gene Transfer in Bacteria and Their Viruses): Bacterial conjugation

^ Griffiths et al (2000), Chapter 7 (Gene Transfer in Bacteria and Their Viruses): Bacterial transformation

^ Griffiths et al (2000), Chapter 5 (Basic Eukaryotic Chromosome Mapping): Nature of crossing-over

^ Griffiths et al (2000), Chapter 5 (Basic Eukaryotic Chromosome Mapping): Linkage maps

Doing this will also decrease the article size and hence improve the load time. SandyGeorgia (Talk) 04:19, 20 March 2008 (UTC)

 Done That shaved 4KB off of the refs, makes it easier to get around in the article to edit, and makes the footnotes much more readable. The book chapters, accessed online, are missing retrieval dates, but you can probably argue that they are just convenience links; clicking on each one of them to verify an accessdate was more work than I wanted to undertake :-) SandyGeorgia (Talk) 00:39, 22 March 2008 (UTC)

Thank you for all your help! I've learned a lot too, so hopefully I won't make as many mistakes in the future. Madeleine ✉ ✍ 04:17, 23 March 2008 (UTC)

Genetically-Modified (GM) Food

While it's true that the article should try to encompass all things related to genetics, I feel the added section was problematic: it's too specific, it's using a lot of political phrases ("agribusiness") rather than scientific ones, and it's off topic—eg. arguments regarding potential global food shortage. The current article does mention and link to genetically modified organisms and could probably benefit from another sentence or two on that topic, but I feel it should be scientifically descriptive rather than describing the politics of the issue. The politics of GMOs belongs on the GMO page, not the Genetics page.

That's not quite true, though -- social implications / politics related to the science of genetics is a whole high level topic the page could benefit from having, but it would need to also include other things like eugenics and maybe evolution... maybe best to start by making a separate article first and then, once it seems broad enough in coverage, summarize it here. Madeleine ✉ ✍ 13:47, 31 March 2008 (UTC)

I agree that the content you cut was very out of place in this article. The paragraph said nothing in the context of genetics. In the section titled 'research techniques' GMO's are mentioned and linked to in the context of genetics though, so it seems it might be redundant too. David D. (Talk) 15:16, 31 March 2008 (UTC)

I agree too; it doesn't belong here. Graham. --GrahamColm^Talk 17:25, 31 March 2008 (UTC)

A question for Timmy: If your not interested in the 'Politics of GMO' but on the science of genetics, then why did you write this: 'Genetic engineering Ho has expressed concerns about the spread of altered genes through horizontal gene transfer and that the experimental alteration of genetic structures may be out of control. One of her concerns is that the antibiotic resistant gene that was isolated from bacteria and used in some GM crops might cross back from plants by horizontal gene transfer to different species of bacteria, because "If this happened it would leave us unable to treat major illnesses like meningitis and E coli."[7] Her views were published in an opinion article based on a review of others' research.[8] The arguments and conclusions of this article were heavily criticized by prominent plant scientists,[9] and the claims of the article criticized in detail in a response that was published in the same journal.[10] A review on the topic published in 2008 in the Annual Review of Plant Biology stated that "These speculations have been extensively rebutted by the scientific community".[11]

http://en.wikipedia.org/wiki/Mae-Wan_Ho

It would appear your not as honest as you would have many believe - because this looks very much like a conflict of interest since she is a world reknown geneticist and you are a biochemist. Which leads me to ask you - who do you work for - who gives the grant money for your lab???

Please prove you haven't fallen into this conflict of interest....

thank you —Preceding unsigned comment added by 99.155.85.129 (talk) 19:00, 9 March 2009 (UTC)

New at this wiki stuff - just clicked on 'unsigned' link - okay - i'll sign it here...

Thank You - Jon —Preceding unsigned comment added by 99.155.85.129 (talk) 19:10, 9 March 2009 (UTC)

New gene expression paragraph

What is the need for this new paragraph added to the gene expression section: [4] ? I don't understand what need it's addressing. It's introducing a lot of jargon and is redundant with the later information. I'd like to know the reason for the addition? -- Madeleine ✉ ✍ 13:36, 15 May 2008 (UTC)

I've removed it, it was redundant and confusing. Tim Vickers (talk) 16:14, 15 May 2008 (UTC)

Sedgwick?

The article says, "The word genetics itself was coined in 1905 by William Bateson, a proponent of Mendel's work, in a letter to Adam Sedgwick." But if you click on Adam Sedgwick you will read that he died in 1873. Somehow I doubt that Bateson was writing to a guy who'd been dead for over 30 years. NCdave (talk) 09:34, 19 May 2008 (UTC)

The William Bateson article further confuses things by referring to an unlinked "Alan Sedgwick". Alternatively, perhaps Bateson was a secret spiritualist and was trying an unorthodox approach to contact Adam Sedgwick?  ;-) Anyway, looks like there's some digging around to be done to resolve this one. --Plumbago (talk) 09:58, 19 May 2008 (UTC)

Good catch! I'm not sure whether the guys name was "Adam" or "Alan". "Adam" was used in this 1998 paper [5] but the site hosting the letter itself [6] names him as "Alan". Either way, it's obviously a different guy from the linked one (maybe a relative?), and not very famous, so I've removed reference to the name. Madeleine ✉ ✍ 11:39, 19 May 2008 (UTC)

It's a different Adam Sedgwick. This one: Adam Sedgwick, MA, FRS, Fellow and Lecturer at Trinity College, Cambridge. A zoologist. In whose edited volumes Bateson had published. --98.217.8.46 (talk) 00:28, 12 July 2008 (UTC)

Siamese cat example

Being indentured to a Siamese cat, I found this example especially interesting.

I realize it may go beyond the scope of the article to answer my question but I'll ask it anyway.

Is the dark fur at the cat's extremities helpful to the cat in some way, or is this dark fur just a "side-effect"?

My impression, which may be wrong, is that this cat's fur changes colour with the season.

Thanks, Wanderer57 (talk) 00:56, 12 July 2008 (UTC)

I'm not aware of this type of mutation having an evolutionary advantage, although there may be speculation out there. This temperature sensitive mutation is also found in mice and rabbits, where it is called "himalayan". I think probably it's just a simple sort of mutation to get, like a form of partial albinism. Because the mutation is temperature sensitive, changes of season mean that the ambient temperature changes, which affects the skin temperature—and so the cat changes color. Eg. in winter it's colder, so the cat gets darker. Unless you have the heater on all the time, in which case it's actually warmer and the cat gets lighter. :-) I also have a cat with this mutation, the somewhat less demanding Ragdoll breed. Madeleine ✉ ✍ 13:20, 12 July 2008 (UTC)

Concerning non-coding DNA

This article is very nice in many ways, but it has one quite serious problem: it gives the impression that the only thing DNA does is to code for proteins. In fact only about 1% or less of the DNA consists of codon domains. These are surrounded by regulatory regions, chopped up by introns, and separated by long stretches whose functions are almost completely unknown; also there are parts that code for RNA assemblies which are not translated into proteins. Interest in this non-coding DNA and its possible functions has grown enormously over the past few years. I would like to edit the article, by making some minor changes to misleading statements in the intro, and adding a section on non-coding DNA, but thought it would be a good idea to ask for reactions here first.Looie496 (talk) 01:14, 12 July 2008 (UTC)

Hi Looie496: Here is my "off-the-cuff" reaction to your suggestion. I think what you propose would be going into too much technical detail, inappropriate to this article. This is an article on genetics, not on DNA. All that belongs here is a general understanding of the basic role of DNA in conveying genetic information. The type of information you suggest belongs, IMO, in an article on DNA.

Perhaps it would suffice, in this article, to add one (or maybe two) sentences indicating that DNA has functions/properties that are not understood. (Plus a reference to the DNA article.) Wanderer57 (talk) 02:09, 12 July 2008 (UTC)

I think it would be best to wait until the page is no longer on the front page to make major changes to the article. Noncoding transcribed DNA has been covered by the article (search on "ribosomal RNA"). The effect of transcription factors has been covered. Other noncoding DNA is, to a large extent, parasitic self-replicating elements—to the extent that these have any functionality, it is far from fundamental to the basis of inheritance: bacteria do not have junk DNA bulking up their genomes and some eukaryotes seem to have gotten rid of their "junk DNA" (eg. fugu). As for the intro/exon stuff, I think that is best covered within the gene article—it is not fundamental to inheritance (bacteria don't do it) and would require a lot more detail about transcription and RNA processing than this article enters into. Madeleine ✉ ✍ 03:38, 12 July 2008 (UTC)

"The sequence of nucleotides in a gene is translated by cells to produce a chain of amino acids, creating proteins" To imply that genes always code for protein is simply wrong. If you present a half truth as the whole truth it is in the end a complete lie. It also seems bold to belittle the role af genes encoding functional or regulatory RNA, there is a lot more to it that "just" ribosomal RNA and tRNA. In the words of one reviewer: "Small noncoding RNAs have been found in all organisms, primarily as regulators of translation and message stability" (Annu Rev Microbiol. 2004;58:303-28. The small RNA regulators of Escherichia coli: roles and mechanisms*.Gottesman S). —Preceding unsigned comment added by 130.226.87.177 (talk • contribs) 08:09, 12 July 2008

From this same article, I quote: "The most exhaustive searches have taken place in E. coli, resulting in identification of more than 50 small RNAs, or 1%-2% of the number of protein-coding genes." To teach the subject to someone new to the material I think it's best to start with what is generally true and then note the exceptions. MicroRNA, eukaryotic RNAs similar to the small RNA's in E coli in the article you provided, are also mentioned in the article next to tRNA and rRNA. If the reader wishes to read more about non-coding RNA they may click on the link provided, right? How would you propose changing the article? I take it you're mostly upset by the absoluteness of the statement in the lead? Madeleine ✉ ✍ 13:34, 12 July 2008 (UTC)

Taking another look at the lead section, I'm struck by how "ambitious" it is. From ancient crop plant selection, to Mendel, to DNA coding for protein. I think we should be looking to make the lead section more "high-level" and less ambitious in what it tries to cover. Non-coding DNA and RNA are not essential topics to introduce into the first four paragraphs of someone's introduction to genetics. (IMO) Wanderer57 (talk) 14:42, 12 July 2008 (UTC)

I certainly have no intention of touching the article while it is on the front page. Anyay, the basic issue is that a reader ought to understand that coding DNA only makes up about 1% of the human genome. There is a lot of info in the article about how genes give rise to proteins, so I don't think it would unbalance it to briefly say something about what the other 99% of the genome does. It is also, in my view, not out of place in an article on this level to point out that genes consist not just of codon sequences, but also of the regulatory domains that surround them. These are of major importance, even in a basic article like this one, because they determine which genes actually get expressed in a given cell. All cells in the body have the same set of genes -- it is the regulatory domains that allow different cells to do different things.Looie496 (talk) 17:34, 12 July 2008 (UTC)

Well, the page has moved on! I fear contributing to the mysticization of "junk DNA" as having some functionality scientists have been unable to elucidate (eg. Darwin's Radio). Maybe you could go ahead and make an addition, or if you're not sure make an outline here of things that you think should be added? Madeleine ✉ ✍ 05:25, 13 July 2008 (UTC)

Introduction

Obviously there's disagreement here--among editors and more generally. But I'd opt for treating genetics as a subsicipline of biology, which is itself a discipline. —Preceding unsigned comment added by Garychartier (talk • contribs) 05:50, 12 July 2008 (UTC)

Bad text added..

The following text was added recently in the opening section:

"Genetics is that branch of biology,which deals with heredity and genetic variability of traits,from parents to offsprings through selective breeding,natural or artificial,in living organisms..."

For a star rated article that made it to the front page, this really doesn't look right. —Preceding unsigned comment added by 194.46.242.59 (talk) 18:44, 12 July 2008 (UTC)

Fixed. Madeleine ✉ ✍ 19:17, 12 July 2008 (UTC)

Quibble about vocabulary

REGARDING THE wording: "James D. Watson and Francis Crick solved the structure of DNA in 1953", it seems to me that "determined the structure" would be a clearer wording. Wanderer57 (talk) 20:47, 12 July 2008 (UTC)

That sounds good to me. I only want to avoid the word "discover" because they didn't actually do experiments (but did use data from others' experiments); "determine" works very well. I've made the change, thanks! Madeleine ✉ ✍ 05:16, 13 July 2008 (UTC)

You could be complete agnostic and say "announced", if you wanted. ;-) --98.217.8.46 (talk) 05:09, 19 August 2008 (UTC)

Editing "natural selection and evolution"

I believe there are some mistakes here.

For example;

Over many generations, the genomes of organisms can change, resulting in the phenomenon of evolution.

I don't think that it can be considered evolution when it uses natural selection without macroevolution. Since the genetic information can change without gaining new genetic information. It should then read "resulting in natural selection"

Another example;

Mutations and the selection for beneficial mutations can cause a species to evolve into forms that better survive their environment, a process called adaptation.[63]

This was taken from Darwin's book. It however also reads that a species can evolve and yet doesn't give a clear reference as to how, i.e. macroevolution or microevolution. Though it may refer to macro evolution, the article should say so to avoid confusion between the two.

66.74.230.117 (talk) 14:29, 13 July 2008 (UTC)

I think further clarification of these comments would be helpful.

For example, the first comment suggests a revised wording:

Over many generations, the genomes of organisms can change,
resulting in natural selection.

It seems to me that the reverse is true, that:

Over many generations, mutations and natural selection result in changes
to the genomes of organisms.

Wanderer57 (talk) 15:05, 13 July 2008 (UTC)

I'm sorry, I don't understand the point here - I would read "genomes ... change" as inclusive of both natural selection and random drift - both of these contribute to "evolution". The whole point of the sentence is to introduce the concept of evolution, so you shouldn't be removing that word from it.

What do you mean by distinguishing between "micro" and "macro" evolution? According to the Evolution wikipedia page, the difference between these is not a fundamental one, it is simply the amount of time involved. If you're concerned, maybe you could drop a note on the Evolution talk page to ask them to take a look at it. Madeleine ✉ ✍ 16:35, 13 July 2008 (UTC)

PS - I think we'll have to take this IP's criticism with a grain of salt; it's associated with some disruptive edits objecting to content within the Objections to evolution and doesn't seem to be coming from someone with significant experience in the field. Madeleine ✉ ✍ 16:44, 13 July 2008 (UTC)

Current version looks fine to me. Tim Vickers (talk) 17:09, 13 July 2008 (UTC)

"The whole point of the sentence is to introduce the concept of evolution, so you shouldn't be removing that word from it."

Yes, it was to introduce the concept of evolution, but, evolution uses natural selection only the mutations require gain of new genetic information. In natural selection, the genetic information simply changes. There is a difference between the two. 66.74.230.117 (talk) 21:26, 13 July 2008 (UTC)

Mutation and gene flow increase genetic diversity, natural selection and genetic drift reduce genetic diversity. The combination of these processes result in evolution - progressive shifts in allele frequency over generations. Tim Vickers (talk) 17:52, 15 July 2008 (UTC)

Maurice Wilkins?

Although we are all familiar with "Watson and Crick", and they are the authors of the seminal paper, should some discussion of Maurice Wilkins' contributions be included? Rosalind Franklin is (appropriately) mentioned here, but why not Wilkins? The 1962 Nobel prize had all three scientists (Watson, Crick, Wilkins) as winners.Rwintle (talk) 17:52, 18 August 2008 (UTC)

Added. (Of course, Franklin didn't win because she was dead.) Madeleine ✉ ✍ 19:49, 21 April 2009 (UTC)

Thank you, Madeleine.Rwintle (talk) 17:59, 20 May 2009 (UTC)

monohybrid crossing

process(es) in crossing monohybrid —Preceding unsigned comment added by 203.84.174.138 (talk) 10:36, 19 September 2008 (UTC)

Genetics and infections; A missing link.

The articile on genetics, appears to focus merely on one component of disease. For example, if a person is genetically predisposed to some disease, because they have no known contact nor immunity to a particular infection, then genetics is merely one part of the whole picture.

I would hope someone has written up on the connection between immunity to an infection and disease. It appears today we merely focus on the genetic component without mentioning the 'infection' component... ?

--Caesar J.B. Squitti: Son of Maryann Rosso and Arthur Natale Squitti (talk) 15:18, 4 October 2008 (UTC)

• human genetic diseases

I am certain most all diseases can be attributed to genetics, however as it is mentioned in the first paragraph, as in height diet is important. To focus merely on genetics without focusing in on 'the infection' leads us down another half-truth path.

--Caesar J.B. Squitti: Son of Maryann Rosso and Arthur Natale Squitti (talk) 15:33, 4 October 2008 (UTC)

Although genetics plays a large role in the appearance and behavior of organisms, it is the combination of genetics with what an organism experiences that determines the ultimate outcome. For example, while genes play a role in determining a person's height, the nutrition and health that person experiences in childhood also have a large effect.

• For example while genes play a rote in a persons ability to cope with a disease, contact with a known virus or bacteria will ultimately impact the probability of developing the disease.

For example people who are not from countries that have 'beaver', have not developed an immunity from beaver feces infections ?

--Caesar J.B. Squitti: Son of Maryann Rosso and Arthur Natale Squitti (talk) 15:46, 4 October 2008 (UTC)

This article focusses on genetics because it is the article about genetics. The general article on disease is the one where your suggestion might be more appropriate. Tim Vickers (talk) 15:46, 4 October 2008 (UTC)

Mendelian and classical genetics

The importance of mendelian genetics is profound, however very little or nothing has been given over here.

"Mendel traced the inheritance patterns of certain traits in pea plants and described them mathematically."

This is not satisfactory. Where are the Mendel's three laws of classical genetics?

I am surprised that not a single reference has been made to Morgan and his work with Drosophila, sex linkage and how he identified the red eye gene on the X-chromosome. There is no information given regarding linkage and chromosome mapping, and important subjects like deviations from Mendel's laws, incomplete dominance, diseases of the X-chromosome like haemophilia, sickle cell anaemia, etc. These need to be added to actualy call this a featured article on genetics. Proquence (talk) 08:21, 26 November 2008 (UTC)

The first and second laws are explained within the "Features of inheritance" section. Morgan is mentioned the History section and the first image not only describes but is actually from his work that you mention. Sickle-cell anemia (which is not X-linked) is mentioned in detail in the "Genetic code" section, and X-linked mutations, although not covered in depth, are mentioned in "DNA and chromosomes". Madeleine ✉ ✍ 19:43, 21 April 2009 (UTC)

Research techniques

I've been reading through this article - it looks pretty good. It is large, but there is so much to say about genetics. Despite the size I thought a bit on electrophoresis might help the research techniques section. I notice that the article says nothing about electrophoresis, yet it is the primary research tools for separating, sizing, and sequencing DNA. When people visit my genetics facility I find that they understand the process better once they understand the separation techniques.Thompsma (talk) 00:14, 17 January 2009 (UTC)

Good point! A sentence and picture have been added. Thanks for the suggestion! Madeleine ✉ ✍ 19:36, 21 April 2009 (UTC)

serial comma

Please keep it consistent. Most of the lists here use the serial comma, and it aids in clear, precise writing, so I'd recommend it be used everywhere in this article, but either way, it needs to be consistent.--75.45.119.241 (talk) 18:34, 10 February 2009 (UTC)

A Comeback for Lamarckian Evolution?

The wikipedia entry for evolution needs to be updated to accurately reflect this new study. http://www.technologyreview.com/biomedicine/22061/ the introductory paragraph to the history of genetics reads: Another theory that had some support at that time was the inheritance of acquired characteristics: the belief that individuals inherit traits strengthened by their parents. This theory (commonly associated with Jean-Baptiste Lamarck) is now known to be wrong—the experiences of individuals do not affect the genes they pass to their children.[7] . clearly it is not know to be wrong and the article i provided is reasonable proof to suggest a step back from proclaiming such facts. —Preceding unsigned comment added by 68.82.204.202 (talk) 17:34, 19 February 2009 (UTC)

I've added a sentence on the possible relationship between evolution and epigentics to the evolution article, using PMID 16534512 as a reference. Tim Vickers (talk) 01:15, 22 February 2009 (UTC)

Genetics does mention that some epigenetic inheritance can span generations, although to call this "Lamarckian" would require it to be an adaptive change in response to environment.

The new research seems to indicate something along these lines, but I believe we should be cautious about changing the encyclopedia article based on any surprising new research findings. Past experience tells me that it's best to wait to see that it's reproduced and is fairly solidly supported. For example, in 2005 there was a lot of press about a report of generation-skipping inheritance of the HOTHEAD gene in Arabidopsis thaliana (published in Nature), seeming to indicate that some non-DNA reservoir of inherited material existed. As I understand it that hasn't been reproduced and others have challenged the results as an artifact of pollen contamination. Surprising findings are important to follow up on with more research, but it needs more confirmation before you should use it in an encyclopedia. Madeleine ✉ ✍ 20:12, 21 April 2009 (UTC)

Not only were the HOTHEAD results not reproduced, they were shown to be the result of contamination (WT pollen was the source of the reversions). Epigenetics has some characteristics of Lamarkian evolution, in that mutations are not required, but epigenetics is not Larmarkian since the classic examples include physical alterations. While stretching a giraffe neck could be accounted for by a epigenetic change in the regulation of some growth factor, in no way could epigenetics account for the removal of tails, or similar changes, being heritable. David D. (Talk) 20:19, 21 April 2009 (UTC)

Yes, the hothead mutants were much more likely to outcross than WT plants. That was just an artifact. Tim Vickers (talk) 20:37, 21 April 2009 (UTC)

Seriously? How did this get included?!

When the discription of this page is shown in google this is what is seen: About|the general scientific term|the scientific journal|Genetics this page is gay so don't read it. seriiosly anyone can just go on it and edit this page ... I'd like to change it myself but im not sure how —Preceding unsigned comment added by 71.58.231.92 (talk) 01:37, 9 November 2009 (UTC)

Cancer inheritance

So under the Medical Genetics section, 2nd paragraph, there is a sentance which is as follows "Although it is not an inherited disease, cancer is also considered a genetic disease.". I cannot believe someone actually wrote this! Furthermore, I cannot believe no one else has called out this persons stupidity! Honestly, Fanconi Anemia (pick one of many FA genes), HEREDITARY Breast and Ovarian Cancer (BRCA1, BRCA2, CHEK2, ATM, P53 etc etc etc)... I can go on for pages... Cancer can absolutely be an inherited disorder and this completely ignorant sentance should be rectified immediately! —Preceding unsigned comment added by 70.55.81.125 (talk) 02:11, 25 October 2009 (UTC)

Good point, there are several forms of familial cancer. I've reworded the article to state Although it is not usually an inherited disease, cancer is a genetic disease, since most cases of cancer are not inherited. Tim Vickers (talk) 02:53, 25 October 2009 (UTC)

Strictly speaking, cancer is never inherited. Cancer is cell's development programs gone haywire – if you'd inherited it, you'd never have made it from a zygote to a fetus. No-one ever inherits a cancer tumor from a parent. I remember a third year genetics lecturer being very adamant about this. What can be inherited is a predisposition toward developing cancer. The point didn't seem worth fussing about in that paragraph, so I just changed the sentence to "Cancer is a genetic disease." Adrian J. Hunter^{(talk•contribs)} 15:05, 23 June 2010 (UTC)

I thought it was a pity you didn't feel like fussing about it in that paragraph, so now I put in the predisposition. :) Lova Falk talk 15:06, 24 June 2010 (UTC)

Sorry, it was late. Your addition looks good, though I removed "thus", because even if individuals did not differ in their inherited cancer risk, cancer would still be a genetic disease. Adrian J. Hunter^{(talk•contribs)} 05:29, 25 June 2010 (UTC)

You're quite right. I never had a third year genetics lecturer so I am happy that you checked and corrected. :) Lova Falk talk 09:54, 25 June 2010 (UTC)

Natural selection and evolution

Just did some editing to the natural selection and evolution section. Most changes were an attempt to make it read better. I tried to keep the individual points the same, but if I have altered the meaning of a sentance excessively then let me know or feel free to change it. Aircorn (talk) 12:20, 10 December 2009 (UTC)

New scientific evidence shows the Han Chinese evolved separately and have DNA genes from Homo Pekinensis and NOT African Homo Sapiens like everyone else

I am a scientist who specializes in the fields of anthropology and paleoanthropology, I would like to introduce to you the peer reviewed scientific evidence supporting a separate independent evolution of the modern Chinese people from an archaic species of Homo Erectus, specifically the separate species known as Homo Pekinensis. Below I have provided the results of scientific DNA studies that provide strong irrefutable support for an independent origin of the Chinese from Homo Pekinensis. These scientific studies have all been published in peer reviewed scientific journals and are well received by the scientific community. Please take some time to read them and feel free to ask me any questions regarding human evolution.

1.) Genetics Society of America's Genetics Journal, "Testing for Archaic Hominin Admixture on the X Chromosome: Model Likelihoods for the Modern Human RRM2P4 Region From Summaries of Genealogical Topology Under the Structured Coalescent" by Murray P. Cox, Fernando L. Mendez, Tatiana M. Karafet, Maya Metni Pilkington, Sarah B. Kingan, Giovanni Destro-Bisol, Beverly I. Strassmann and Michael F. Hammer.

2.) Oxford University's Oxford Journals, Evidence for Archaic Asian Ancestry on the Human X Chromosome by Daniel Garrigan, Zahra Mobasher, Tesa Severson, Jason A. Wilder and Michael F. Hammer

3.) Oxford University's Oxford Journals Global Patterns of Human DNA Sequence Variation in a 10-kb Region on Chromosome 1 by Ning Yu, Z. Zhao, Y.-X. Fu, N. Sambuughin, M. Ramsay, T. Jenkins, E. Leskinen, L. Patthy, L. B. Jorde, T. Kuromori and W.-H. Li

4.) BMC Biology Journal of Biology "Y chromosome evidence of earliest modern human settlement in East Asia and multiple origins of Tibetan and Japanese populations" by Shi H, Zhong H, Peng Y, Dong YL, Qi XB, Zhang F, Liu LF, Tan SJ, Ma RZ, Xiao CJ, Wells RS, Jin L, Su B.

5.) National Geographic Society Peking Man (Homo Pekinensis) Lived in China 200,000 Years Earlier Than Previously Thought

It is tempting to simply dismiss the new peer reviewed scientific evidence that contradicts the previously accepted "out of Africa" theory of human evolution where, supposedly, all humans were descended from the same group of Homo Sapien ancestors and which subsequently gives "strong support" in favor of an independent East Asian origin of a separate archaic branch or separate species of humans, the modern day Chinese people. But unfortunately, the reality of human evolution during the past 4 billions of life on our planet Earth is not as clear cut as the "out of Africa" theory attempts to address it. The "out of Africa" theory tries to say that "ALL" humans are descended from the same group of anatomically modern "Cro Magnon" or Homo Sapien Sapiens and while some of the older previous studies did initially seem to support that theory, those studies were not all inclusive and did not test many aspects of human genetics and evolution. But within the last few years, new genetic evidence has been discovered as a result of numerous scientific studies that have been conducted which lend a strong support for the theory that the modern Chinese people, or conservatively, a subpopulation of the Chinese gene pool are descended NOT from anatomically modern African Homo Sapiens like other humans on Earth, but rather that they are the product of a separate evolutionary lineage going back at least 1.8 million - 2 million years ago to Homo Erectus in East Asia. And that the modern Chinese people today are not necessarily classified as "Homo Sapien," but more accurately they could be classified as a highly evolved anatomically modern form of Homo Pekinensis. You must remember that regardless of whether we are talking about Homo Neanderthalensis or Homo Erectus that we are talking about human beings. And even though they are a classified as a separate species of human beings, nothing can take away their "humanity," for if one of them were dressed up in a modern day suit, they would still be recognized as "humans."

Please watch the evidence on these links:

1.) Scientific evidence from the Chinese Academy of Sciences
2.) All Non Africans Living Today Are Part Neanderthal
3.) New evidence that Neanderthals interbred with Humans

Adding further support to the Multi-regional theory of human evolution are the recent DNA discoveries that anatomically modern African Homo Sapiens interbred with Homo Neanderthalensis or the Neanderthal man, in direct contradiction to the thesis of the "out of Africa" theory which specifically states that Homo Sapien did not interbred with Homo Neanderthalensis and that the Neanderthal simply "went extinct." Which has now been shown in peer reviewed scientific studies to be untrue, and that the Homo Sapien and Homo Neanderthalensis did indeed interbreed with each other. These studies are additionally supported by previous archaeological finds that show skeletons of humans who show hybrid morphological and anatomical traits of both species of humans, both Homo Sapiens and Homo Neanderthalensis.

Please read the following evidence:

1.) NewScientist Neanderthal genome reveals interbreeding with humans
2.) Archaic admixture in the human genome, Neanderthal genes in modern humans
3.) Signs of Neanderthals Mating With Humans
4.) Discovery News "Neanderthals, Humans Interbred, DNA Proves"
5.) USA Today Neanderthals and humans interbred, fossils indicate
6.) BBC "Neanderthals 'mated with modern humans'"
7.) Official report Neanderthal/Homo Sapien interbred
8.) Cosmos Humans and Neanderthals interbred, according to our anatomy
9.) Neanderthals live on in DNA of humans

The previous "out of Africa" model is only partial correct, while evidence shows there was indeed an out of Africa migration of Homo Sapiens, it does NOT mean that all humans are descended from this small population of Homo Sapiens. In Europe, the archaic humans, Homo Neanderthalensis, existed independently and interbred with these African Homo Sapiens resulting in the 1%-4% genetic admixture of all non-Africans. And in the case of the Chinese, numerous scientific studies have been published showing both genetic and fossil evidence that the modern Chinese people possess a different nucleotide encoding in their DNA, which in simplest terms means the Chinese have genes and other DNA fragments which they inherited from their Homo Erectus Pekinensis ancestor. Additionally, fossil evidence unearthed at the Zhoukoudian archaeological site have shown Homo Pekinensis fossils to have a continuity of anatomical and morphological traits with many modern Chinese people. All of the archaic East Asian Homo Pekinensis and Homo Erectus fossils studied have shown a continuity of unique morphological and anatomical traits, such as flattened faces, small frontal sinuses, reduced posterior teeth, shovel-shaped incisors, and high frequencies of metopic sutures, which are virtually absent in modern day European, Middle Eastern, and African populations but widely present in the modern population of the Han Chinese.

Thank You Very Much! —Preceding unsigned comment added by 72.215.64.102 (talk) 16:38, 18 August 2010 (UTC)

My earlier attempt to move this unsigned new section to the expected place for new sections was eaten by an edit conflict. New sections belong at the bottom of talk pages. That makes section editing of talk pages go more smoothly. Well, then, now I will respectfully disagree with this new section. The sources mentioned are not reliable sources for unusual claims in Wikipedia articles. Until this speculative hypothesis filters into mainstream scientific literature (which I don't think is very likely), it doesn't belong in a Wikipedia article. -- WeijiBaikeBianji (talk) 16:49, 18 August 2010 (UTC)

Agree not sure y it was removed...i moved it down here..As to the argument sounds promising , but as mentioned by WeijiBaikeBianji it does not seem to be mainstream but rather a new theory put forth.Moxy (talk) 16:51, 18 August 2010 (UTC)

If I'm understanding the original poster correctly, the key policy here is original research, specifically the section on synthesis of published material. Even if the original poster's sources are reliable, they do not appear to directly support an independent origin of Chinese people – that's a novel conclusion drawn by the poster. WP:REDFLAG is also relevant – this is such an extraordinary claim that it could only be included if it were made by a very high-quality source. Adrian J. Hunter^{(talk•contribs)} 12:30, 19 August 2010 (UTC)

I was discussing this in a Biological Anthropology class last thursday. Its a new theory with questionable methods but already has developed strong supporter in Chinese circles. I know on member of the faculty is convinced its more ethnocentrism than science. It will be a year or two years before the american academy will be able to verify it. There been a suggestion of it before but its been mostly dismissed this is one the first groups to take the idea seriously At this point it would consitute a notable fringe theory but not much beyond that. (Please not i am only a Junior in ungrad of anthropology BS and most of this analysis come form my professor.)BB7 (talk) 01:12, 14 September 2010 (UTC)

I don't know about the Chinese thing (first I heard of it), but the Neanderthal thing has certainly gotten legs as least as a theory. Gone from a wacky, disreputable idea, to pretty close to "most likely". Even if not 100% proven, it's been in major science journals as well as popular media. I think to really report on the story of human evolution, you need to cover areas where there is still disagreement and evolving thought (not nescessarily picking a side, but just reporting on the different schools of thought, especially when the debates are notable). Obviously all this stuff with human evolution gets touchy wrt ethnic and political and racial issues. But at the end of the day, something physically happened, regardless of what we want to have happened. Also, the actual evolution may not be as simple as we want it to be. Populations can evolve in different directions in different regions, but still have multiple founders, re-insertion of genes from (relatively) isolated groups because of migrations, etc, yada, etc. We are talking about a long time ago, and we lack a time machine, but the field of population genetics is "hot" and more and more able to start delving into these things. We've come a long way since Leakey's fossils and the next 10 years will be exciting scientifically and probably entertaining in the associated kerfuffles in the lay press.TCO (talk) 17:29, 23 December 2010 (UTC)

This is not in tune with the most recent scientific interpretation of the genetic data and I am a geneticist. Here is a quote from a recent Nature article[7] that is relevant to this:

"A report by Liu et al., just published in Proceedings of the National Academy of Sciences[8], describes modern-human remains from south China that are dated to more than 100,000 years ago. 'Most researchers' would agree that Homo sapiens originated in East Africa between about 190,000 and 160,000 years ago; that members of the species briefly entered the Levant some 100,000–60,000 years ago (when they were displaced by Neanderthals); but that they did not disperse across southern Asia and to Australia until 50,000–60,000 years ago. The new Chinese find implies that they could have left Africa up to 50,000 years earlier — how likely is this?"

The documentary show The Incredible Human Journey did an episode on this issue [9][10] and you can clearly see that this is a sad case of ethnocentrism rather than science. Look at 7:40 in the second video to learn about the research by Li Jin - who did a genetic analysis questioning this issue and found that this claim toward Homo erectus could not be supported. He sampled over 163 ethnic groups over 12, 127 DNA samples and found that everyone was from the African descent. Here is the publication: [11] in Science. It is pretty clear cut - China is from the same genetic stock as the rest of us, out of Africa.Thompsma (talk) 00:39, 3 February 2011 (UTC)