Talk:Twin

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[edit] Causes?

What are the causes of identical twins and non identical twins? I dont know do you?

Someone please write a paragraph about criminality and penal code with regards to twins. Ex: if CCTV footage shows a person committing murder while lying in wait, and he/she is one of identical twins and they refuse to confess, do both of them get sent to the gas chamber? Issues like this are very popular in crime fiction stories and movies. Also, there was a recent news story about brazilian twins, who both sat in prison for drug trafficking, but one got released instead of the other due to tricking and bribe. He got caught and now both will have to serve some extra years for obstructing the way of justice.

It would be interesting to do some research and figure out how much of this stuff actually happens in real life. (I am reminded of a story arc on Without a Trace in which one identical twin tricks his brother into acftually confessing a crime.) The use of twins in mystery stories is worth talking about in and of itself. (Notice that I'm not volunteering.) -Aranel ("Sarah") 00:05, 14 July 2005 (UTC)
I don't think this topic is notable enough to be included, as these kinds of things are extremely rare. This article is also not about fictional account of twins.Beach drifter (talk) 20:10, 7 February 2008 (UTC)

[edit] Identical twins not the same sex?

The article has this line:

Monozygotic twins are genetically identical unless there has been a mutation in development; they are only usually, but not necessarily, the same gender.

Could someone provide a refrence for this, it seems rather unbealievable, or seems like something that would require a very specific mutation in one of the twins, and thus exceedingly rare. If true, it needs more of an explination than the simple statment given. When such a thign happens are there other medical considerations? How rare is it? Is it even common enough to be called out in the article without saying that it is exceedingly rare? Dalf | Talk 18:22, 16 May 2005 (UTC)

well, although it is very rare, monozygotic twins may be of different genders when an egg containing the abnormal chromosome, xxy, splits into two. Then, one half of the egg is xx, a girl, and the other half is xy, a boy. Otherwise, they still share identical DNA, they just are of opposite genders.


Oops the next paragraph addresses this. Dalf | Talk 18:23, 16 May 2005 (UTC)
read Intersexual 4.250.198.126 19:00, 16 May 2005 (UTC)

I dramtically reduced the amount of text on identical twins not the same gender and removed the section header. It's not a relevant risk of having twins, and so its a nonsequiteur to spend an entire section and two paragraph on the phenomenon. From the sources I've seen, only 3 cases have ever been documented (not "3 in 100,000" or "3 in 1 million" or "3 in 2.5 billion" but just "3". Ever.) To put that into context, you have a greater chance of personally meeting and then going skydiving with conjoined twins than of having different-gendered monozygotic multiples. I do belatedly agree with Violetriga that the Intersexual article isn't directly on point -- I left that in in my initial edit to try to provide context for the description of the mono-multiple gendered process that I felt didn't belong here. I'd be open to putting in a wikilink to a different article that provides that context, but it really doesn't belong here. Any suggestions for where to link to? Nandesuka 10:48, 17 May 2005 (UTC)

Well, identical twin and identical twins redirect here: how about Mixed sex identical twins? -- ALoan (Talk) 11:41, 17 May 2005 (UTC)
That makes a lot of sense to me. We could even take the text I elided regarding XY / XO chromosomes and turn that into the stub of that article. Violetriga, is that OK with you? Do we have consensus? -- Nandesuka 14:02, 17 May 2005 (UTC)
Sorry about the belated response - for some reason I hadn't noticed this discussion. I think the information should certainly be somewhere and I'm not entirely sure that it is worthy of its own stub, hence my preference for inclusion here. If you want to try it and see how well it works then by all means go for it - it may work well. violet/riga (t) 09:49, 2 Jun 2005 (UTC)

I agree that this is rare, but XX/XY hermaphroditism is uncommon; if you superimpose monozygous twinning on that frequency you can get the potential frequency of this event. How relevant? I believe the article generally ok in this regard. It is a curiosity, but one that reminds us that biology is full of rules that can be broken.

"Although their traits and physical appearances are not exactly the same due to environmental conditions in both the womb and outside the womb, they do have the same DNA... Monozygotic twins are genetically identical (unless there has been a mutation in development) and they are the same gender. (On extremely rare occasions, an original XXY zygote may form monozygotic boy/girl twins by dropping the Y chromosome for one twin and the extra X chromosome for the other.)"

The above says that identical twins have the same DNA, but on rare occasions different chromosomes. Doesn't that contradict? Surely it should say that most are genetically identical, but not all? this seems to suggest that identical twins don't necessarily have the same DNA, and can in fact be "profoundly different". What's the truth? Are the genetic differences limited to a potential XXY chromosome as suggested above?

  • The correct term for this section is sex not gender. The two words are not interchangeable. Sex is a biological thing, gender is not. Gender is a psychological thing, a sociological thing. Don't be afraid of sex. It's a word. Write it. Say it. Grow up. —Preceding unsigned comment added by 75.27.41.134 (talk) 22:59, 6 May 2008 (UTC)
Didn't your mama teach you any manners? Beach drifter (talk) 23:10, 6 May 2008 (UTC)

[edit] Foetus in foeto

"Doctors in Bangladesh say they have removed a long-dead foetus from the abdomen of a teenage boy who was complaining of stomach pains. [...] The condition is known as "foetus in foeto", or inclusion twin." (June 2005 BBC article) Google tests for either term (in quotes) yields less than 15 results. "Fetus in Feto" yields about 30 hits, some being non-english pages. Anybody know anything about this? Are the terms wrong? --Nectarflowed T 03:05, 27 Jun 2005 (UTC)

Yes, it's a real phenomenon. There are some researchers who would suggest that a much higher percentage of people than we realize (maybe even a majority) start out as a twin, but the other twin is soon absorbed. (But no, I can't cite references, and I don't know the actual term. There usually isn't going to be a recognizable trace of the non-surviving twin in the sibling's body, though.) -Aranel ("Sarah") 23:57, 13 July 2005 (UTC)
And, hey, this is already mentioned in the article. See parasitic twin (the extreme case) and vanishing twin. -Aranel ("Sarah") 23:58, 13 July 2005 (UTC)

[edit] Singleton

Are you sure this is the correct word? I have never heard it outside of Sex and the City. Trollderella 20:17, 17 October 2005 (UTC)

  • Yes - that's the correct term. violet/riga (t) 21:32, 17 October 2005 (UTC)

It may have been an abdominal pregnancy that died "in abdomino" and then became a scarred fibrotic remnant. These cases are as rare as siamese twins. Often these pregnancies lead to horrid complications. Not related to twinning.


[edit] Congratulations, lady, but...

The image of the woman 'pregnant with twins' is totally out of context for this page. It simply doesn't contribute at all to the subject of the page. I feel a little bit sorry for the girl (and the twins aboard), but this simply isn't the place for that picture. Goodbye and good luck, you three! :) Kreachure 00:53, 4 November 2005 (UTC)

Erm, why does it not contribute? There's a long discussion of twin pregnancy issues on this page - it looks relevant to me. Trollderella 20:23, 4 November 2005 (UTC)
Because the article is primarily about twins, not future mothers of twin, and it smacks of vanity. For the record, I'd have no objection to that picture going on the pregnancy page. Nandesuka 13:44, 6 November 2005 (UTC)
I agree that it's not particularly relevant here. It's a picture of a pregnant woman. The caption says she's pregnant with twins, but that's not something you can know from a photograph. Friday (talk) 15:13, 6 November 2005 (UTC)
Well, fine, I'm not going to labor the point (ha ha!), but the article does devote significant space to the notion of being future mothers of twins. Trollderella 16:25, 7 November 2005 (UTC)

[edit] Half-identical Twins

There seems to be a twin phenomenon not listed on this page: Polar Body Twins (AKA half-identical twins). Appearently they occur when a single egg splits into two parts, both of which are subsequently fertilized. I guess it's just theory at this point (hard to prove with current genetic testing), but maybe it should be up here.

See the section above labeled "semi-identical twins." The phenomenon does not exist except in people's minds. An unfertilized zygote can not split by itself, and if it could it would not still be able to be fertilized. Nandesuka 13:50, 12 November 2005 (UTC)

(I was the first speaker) I did some more looking, and found some more info. Appearently all eggs split before fertilization, resulting in one strong gamete and another weaker one called a Polar Body which just degenerates. The theory is that sometimes, both the egg and the polar body survive, and become fertilized.--Tychomonger 22:32, 12 November 2005 (UTC)

You'll need to cite a reputable medical source for this. We looked into it sometime this past summer on this talk page and did not find any credible sources. Nandesuka 11:51, 16 November 2005 (UTC)

I have never seen any medical citation for this. In addition, if you have two eggs, there is no way you could distinguish this from fraternal twinning, unless you were compulsive enough to notice that fraternal twins differ for every single maternal allele. ~

[edit] Olsen twins? Who needs them?

Excuse me for being old-fashioned, but why do we need a publicity photo of some second-rate Hollywood celebs on what is otherwise a reasnably well written article. Delet the pic! --Hugh2414 17:50, 3 December 2005 (UTC)

I agree mainly because they look so much alike. If there's an image used as a prime example of fraternal twins, wouldn't a pair that can't easily be mistaken for identical twins be better? Coyotecoyote 11:19, 11 December 2005 (UTC)

Or maybe an older pic when they're kids. I get the reason its just not really needed. --KaidenShiba 20:22, 13 January 2008 (UTC)

[edit] Discpreancy between this entry and the entry on Conjoined twins

In this entry, under "Types of twins"/"Identical Twins" it states "Twinning after 12 days post-fertilization will typically result in conjoined twins." with a link to the entry on conjoined twins. However, in the beginning of the conjoined twins entry, it states "Contrary to popular belief, conjoined twins are not the result of an incomplete split of twin embryos; rather, the embryos become joined again after they have already split."

One of these entries is wrong, or this entry is incomplete, and needs a footnote to explain that after 12 days, twinning occurs but with a great possibility of the twins become joined.

The article on conjoined twins is egregiously wrong. I'll find appropriate sources, and update it. Nandesuka 00:52, 18 December 2005 (UTC)
Cool, thats good to know. Thanks!


[edit] Every Other Generation Discrepensy

Is there any proof on the so-called every other generation rule--you know the one that states that not your kids will have twins, but your grandkids will or may?--ChuckDizzle 16:54, 14 January 2006 (UTC)

No~

My mother was a twin, and I'm a twin. Totnesmartin 13:54, 9 December 2006 (UTC)

[edit] oral contraceptives

Removed the line that said dizygotic twins were more likely when conception is soon after the cessation of oral contraceptives

Anyone have a study for this? I know of one that said maybe it was more likely to lead to monozygotic, but it wasn't conclusive and it didn't have findings on dizygotic. - O^O

That section was added by User:Violetriga at 19:36, 12 September 2004. I have asked for a source. -- ALoan (Talk) 23:39, 19 April 2006 (UTC)
It comes from "Mayes' Midwifery - A Textbook for Midwives 12th Edition" ISBN 0-7020-1757-4. violet/riga (t) 18:34, 27 April 2006 (UTC)

[edit] Non-sibling twins?

There was an uncommon case a couple years ago--check it out http://taxa.epi.umn.edu/twinnews/twin_1_2.htm under "A New Type of Twinning" I think that should be included under unusual twinning.

[edit] Predisposition for monozygotic twinning

I have just tagged the following paragraph with {{fact}}:

Fewer than 20 families have been described with an inherited tendency towards monozygotic twinning (people in these families have nearly a 50% chance of delivering monozygotic twins). Some evidence suggests that the environment of the womb causes the zygote to split in most cases

This seems very interesting, and I would be really interested in seeing a reference. For now, none of the documents I have seen mention anything like that, so I noone finds a reference, I'll remove the quote above from the article in the future. Schutz 16:07, 19 April 2006 (UTC)

Good catch. I removed it. Nandesuka 16:43, 19 April 2006 (UTC)
Pity; I am still hoping this is correct and someone will come with a reference... I have not been able to find anything, despite a fair amount of time spent on Pubmed and specialised web sites. Anyone has any idea where to look (or which keyword to use) ? Schutz 22:50, 19 April 2006 (UTC)
That is a really old assertion - added by NuclearWinner (talk · contribs) at 04:58, 30 August 2003 with the comment "improved accuracy, added fun fax re rate of twinning". They made a few edits a few days ago, so it may be worth asking for a source (in fact I see Schutz has already asked). -- ALoan (Talk) 23:34, 19 April 2006 (UTC)
Sorry, I should have mentioned here that I searched for the edit already, so that you don't waste your time searching for it again (especially for an edit that is almost 3 years old...) Schutz 23:42, 19 April 2006 (UTC)

[edit] Recent large additions

The recent large additions to the article were by an anonymous editor and provided no sources. I'm not reverting them though because much of this article is unsourced anyway. The edits appear reputable to me although they are unverifiable without deeper knowledge of the field and links to sources. Please check these edits if you have an expert understanding of biology and can add sources for these additions. — Donama 09:22, 24 May 2006 (UTC)

[edit] The removed section on twins in fiction

==In fiction==

[[Image:NonFreeImageRemoved.svg -->|thumb|right|Captain Kirk with Spock's evil twin]] The theme of the confusion among twins or a character simulating being twins is a millenia-old resource of th ecomedy of errors. Plays featuring twins (real or simulated) include the Roman Menaechmi, Shakespeare's The Comedy of Errors, Dumas's The Iron Mask and Bollywood Gol Maal. Sometimes the twins are divided in a good one and the "evil twin". So that the audience differentiates them, each of the twins (often represented by the same actor) has different hairdos, the stereotypical goatee or clothes. Conversely, film child actors are often twins, since labor laws limit the time a child can work. By alternating the twins for the same character, the shooting speed can match that of adult actors.

Hello -- I am a twinless twin (my identical brother died at our premature birth). I totally missed any information on fate of surviving twins that necesarrily maintain very often unconscious bond with their deceased half ("lone twin syndrome"). The feelings of being utterly lonely and being only half of some lost whole is common to all surviving multiples. How can I correct this article -- to whom must I write suggestions and provide materials pls.?

Sincerely -- Algis Davidavicius (Shim Gong), shimgong@gmail.com.

[edit] The Olsens

I can't beleave Mary-Kate & Ashley Olsen are not identacal.(misspelled)--Cute 1 4 u 21:06, 17 July 2006 (UTC)

[edit] Polar body twins (identical-fraternal twins)

"Polar body or (identical-fraternal) twinning, is thought to occur when a single egg splits prior to fertilization and a separate sperm fertilizes each half. These twins share 75% of their DNA, and like fraternal twins, can be same gender or boy/girl."

As this section is refuted twice above on this talk page I am surprised to see it still in the article and unsourced. Please add proper sources to confirm this if you return this to the article. Rmhermen 16:27, 12 August 2006 (UTC)

I agree that "Polar body" twinning should not be a reference to "semi-identical". I don't believe this is sound science. I attended a talk by Dr. Geoff Machin, a retired twin researcher, last night where he explicitly refuted the misconception that polar body twins result in an in-between or semi-identical twin pair.David reno 22:02, 24 July 2007 (UTC)

[edit] "Famous Twins" list

This was just completely out of control, so I nuked it. Please remember that Wikipedia is not an indiscriminate collection of information. Nandesuka 03:15, 6 September 2006 (UTC)

Well nuked! There is already such a list at List of twins anyway. Gnusmas 08:19, 6 September 2006 (UTC)

[edit] private language

I noticed we have a stub about Idioglossia, which states that twins sometimes have their own secret language (e.g., Poto and Cabengo or June and Jennifer Gibbons). This would go under human twins, clearly, but right now the focus of the text seems to be entirely on biological aspects, not social ones. I'll try and add something in a little while just so the information's there to build on. Phoenix-forgotten 03:22, 20 September 2006 (UTC)

From what I know of it, and being a twin myself, I know my brother better than anyone so when he talks, I can finish his sentence. I can't read his mind, but I often know what he is thinking just because I know him really well, and chances are very high that I'm thinking the same thing. —The preceding unsigned comment was added by 206.202.64.46 (talk • contribs) 15:49, 1 June 2007 (UTC)

[edit] discrepancy in describing twinning rates

i've copied conflicting text from two paragraphs in this article. the issue is whether twinning occurs at a rate of 1:150 or 1:250 births. 68.237.196.135 15:20, 29 September 2006 (UTC)


Identical twins Identical twins occur when a single egg is fertilized to form one zygote (monozygotic) which then divides into two separate embryos. This is not considered to be a hereditary trait, but rather an anomaly that occurs in birthing at a rate of about 1:150 births worldwide


Nevertheless, the rate of identical twins remains at about 1 in 250 across the globe


  • This discrepancy also exists in the Fraternal Twins section where the author says

For example, in New York City's Upper East Side there were 3,707 twin births in 1995; there were 4,153 in 2003; and there were 4,655 in 2004. Triplet births have also risen, from 60 in 1995 to 299 in 2004.

without any distinction of the number of births for that year. These statistics alone do NOT in any way signify an increase in "twin births" since we don't know what the general population correlates are. Were there more births in 2004 than in 1995? Less? These statistics are totally without context... Stevenmitchell 05:25, 12 April 2007 (UTC)

It is usually stated that on world average twins occur 1 in 85 (values range from 1-in-70 to 1-in-90 if you ask different professionals). 81.0.68.145 22:11, 2 June 2007 (UTC)

[edit] duration of pregnancy

Where did the 34 to 36 weeks duration of twin pregnancy come from? I'm a mother of twins myself and I have never heard anything different than 37 weeks, and the first link below gives that as well (22 days early is 37 weeks). I've taken the liberty to change it to 37 weeks anyway. 195.96.121.74 21:07, 5 January 2007 (UTC)

There are some twins, such as myself, that where born early, 34 to 37 weeks would seem more reasonable.—The preceding unsigned comment was added by 206.202.64.46 (talk • contribs) 15:44, 1 June 2007 (UTC)

[edit] Maury???

Under polar twins it says "There has been one case on Maury where the twins had different fathers but they were fraternal." What on earth does "Maury" mean? Is it a place (an island, maybe), or what? The sentence can probably be deleted as unsourced anecdote, whatever maury is! Gnusmas 20:53, 21 January 2007 (UTC)

It just may be a word that I do not know, but perhaps the "Maury" is referencing the American talk show Maury. That would be my guess.Ultatri 02:04, 13 February 2007 (UTC)

[edit] Ethnicity and twins

Did you know Nigerians have twins for every 22 births? And Inuit the lowest twin rate? Twins and race needs to be added.--HalaTruth(ሀላካሕ) 22:09, 22 January 2007 (UTC)

[edit] Need a better picture

That's a bad picture. It doesn't look like twins, just two kids in a tub. Identical twins would be the best for an image. Wujucokola 09:07, 1 March 2007 (UTC)

[edit] Twins and Society

I don't know about this section... it seems controversial and unsubstantiated. Being a twin myself, I can say that some of these notions are just false.

Polar twins reported: [1]

I saw it also. It is a load of rubbish, to put it bluntly. Most 'twins' you meet hate being 'twins' and prefer to be known simply as brothers or sisters. Also they hate the fact that people just look at height, tone etc rather than things that are clearly different. The faces of twins are as similar as non-twin siblings, really. 'Twins' usually want individuality that people don't let them have and some 'twins' get depressed when you call them 'twins'.

That is the cruelty of society, I guess. I would also like to say that twin studies are faulted or atleast my personal studies have shown them to be. King Óðinn The Aesir 09:23, 12 May 2007 (UTC)

So it was in good nature that I already deleted it before seeing such concerns? Good, because for the same reasons you've given I felt it was uncited and support stereotypes... Stabby Joe 18:16, 22 June 2007 (UTC)

[edit] Semi-Identical

Im the one who changed the semi-identical section I added a reference but i don't know how to put the in article source, also can someone clean up that part since i did little more than edit what was already there, thx. also how do you post your name at the end? sorry im a Wiki n00b.

BBC news article on the (it claims) first reported semi-identical twins.

What is the difference of reproduction between normal twins and identical twins?

Please note: There have been people typing rubbish in the Semi-Identical section ... I've attempted to delete it (but am for some reason unable) so I thought you should know.

I reported it as vandalism and fixed what I could. You were unable to do so because the article is semi protected and you need to have a user Id to edit such pages. Albion moonlight 11:19, 13 September 2007 (UTC) .........Oh yeah and thanks....Albion moonlight 11:21, 13 September 2007 (UTC)

[edit] Demographics

There are estimated to be approximately 125 million twins and triplets in the world, and just 10 million identical twins.

That is how the introduction discribes the demographics. However, this is what appears in the identical twin subsection:

It is estimated that there are around 125 million identical twins and triplets in the world.

As neither of these are cited, I will be changing the subsection data. However, this should really be researched. Also, it is unclear if they were refering to pairs or individuals, which could drastically change this data.

Fraternal twinning ranges from 1 or 2 per thousand births in Japan (similar to the rate of identical twins) to 14 and more per thousand in some African states.

This appears in the fraternal twin subsection. However, this is what appears in the identical twin subsection:

This is in marked contrast to fraternal twinning which ranges from about 6 per thousand births in Japan (almost similar to the rate of identical twins, which is around 4-5) to 15 and more per thousand in some parts of India

This is cited though, and therefore I will be changing the fraternal twin section.

Someone really needs to look into the original numbers though. I'm no scientist, so I am not in the position to add anything.

Tdmg 18:42, 5 April 2007 (UTC)

[edit] Photos

No photos of identical twins on a page about twins?JayKeaton 09:47, 25 April 2007 (UTC)

As Image:TwinBoysInBathtub.jpg appears to be an un-free image and has been scheduled for deletion on 1 July, I am removing it from the article. --Kralizec! (talk) 16:56, 16 June 2007 (UTC)

http://www.twinsmagazine.com/

http://www.tamba.org.uk/

http://www.twins.org.au/

http://www.twinsdays.org/

[edit] Carlson photo inappropriate

Following the same complaint re. the Olson photo, isn't the Carlson photo out of place here? Beyond being public figures, associated with a clothing brand as well as their own promotional interests, the photo is also sexualized—the photo simply carries too much bias and does not support the article.

Does the concept of 'twins' really need a photo to be understood? Eye-candy that might actually improve the article would be a diagram illustrating some of the science (i.e. showing how identical twins start as one egg that splits, fraternal as two, etc.). —The preceding unsigned comment was added by MarkMabel (talk • contribs) 21:41, 24 May 2007 (UTC)

  • I agree. That photo is basically spam - or at least free advertising for them. I will delete. GNUSMAS : TALK 08:12, 25 May 2007 (UTC)

I think that some pictures could help demonstrate what half-identical and identical twins really are. Some people still insist that if you are identical, like my brother and I, that you look 100% alike. This is not the case, we do look alike, but not 100%, that is impossible.—The preceding unsigned comment was added by 206.202.64.46 (talk • contribs) 15:38, 1 June 2007 (UTC)

It has returned... we're agreed on deleting, right? Bendž|Ť 08:38, 15 June 2007 (UTC)

[edit] Paranormal censorship?

I object that there is zero info in this article regarding ESP phenomenon and twins. It is well-known that twins, especially identical twins, have "status info" on each other without physical contact or infocomms devices, they just feel inside if the other one is in danger, etc. This has been studied much and confirmed. 81.0.68.145 22:08, 2 June 2007 (UTC)

Maybe it has been studied, but never verified by a reputable organization. It's regarded in most circles as a load of rubbish.Beach drifter (talk) 19:27, 6 February 2008 (UTC)

[edit] Quaternary mention?

I not only didn't see any mention of non-communal "quaternary marriages" mentioned in this article, I couldn't find a single mention anywhere on wikipedia. Could quaternary marriages be mentioned or even have its own article? I learned about it earlier today in the letter section of Popular Science and this was basically the only worthwhile web reference I could find outside of discussion about group marriages: [2]

[edit] New Theory on Formation and Heredity of Identical Twins

I added a new theory and also the heredity factor regarding identical twins.

--Florentino floro 13:27, 16 July 2007 (UTC)

[edit] Monozygotic and Dizygotic versus Identical and Fraternal?

I recently attended a lecture by twins researcher Dr. Geoff Machin. He is a contributor to Twins Magazine. He makes a strong case to abandon the old terms of identical twins and fraternal twins in favor of the terms monozygotic (MZ) and dizygotic (DZ). His primary reason is that monozygotic twins are never absolutely identical and can in fact be very different (e.g. different sex, hemophiliac and not hemophiliac, Downs syndrome and not Down's syndrome).

For more information, see the "SEPTEMBER/OCTOBER 2001" issue of Twins Magazine (www.TwinsMagazine.com). Page 22 has the article "Twin zygosity: ‘identical’ or ‘fraternal’?" which is an interview with Dr. Machin. Please comment here if you feel strongly for or against this new terminology. David reno 22:10, 24 July 2007 (UTC)

I fully agree with you here - we should use those terms instead where possible. It is of course still important to use terminology that is commonly understood and expected to be in the article, but we should avoid "identical" in general use within this article. violet/riga (t) 11:22, 25 July 2007 (UTC)

[edit] Born on different days

Does anyone know about any cases where two twins (or if they where triplets or what ever) born on different days as to say one born maybe 23:58 the other 00:01. Or what would be really cool, born in two different years, one before midnight on dec. 31 and the other after . ϲнʌɴɗɩєʀ 04:39, 4 August 2007 (UTC)

That'd be so cool. Cause like one would be December 31 2001 and the other would be January 1 2002. If there are any cases like that then please speak up. --KaidenShiba 20:27, 13 January 2008 (UTC) —Preceding unsigned comment added by KaidenShiba (talk • contribs)

[edit] TTTS - twin to twin transfusion syndrome

"Mono/mono twins have an overall in-utero mortality of about 60%, principally due to cord entanglement prior to 32 weeks gestation. Mono/di twins have about a 25% mortality due to twin-twin transfusion."

As far as I could find out when I was pregnant with my mz/di twins, TTTS can happen in both mono/mono twins, and mz/di. It's the sharing of the placenta that is the key. Perhaps the reference to TTTS should either be removed from the second sentence or included as a factor in the mortality of mono/mono twins. The link to TTTS further down the page also neglects to mention that TTTS can occur in mono/mono twins too. Ozmikawa 12:48, 17 August 2007 (UTC)

[edit] Mirror image twins

I was wondering if something about mirror image twins should be added to the section regarding identical twins? They are a well known subsect of identical twins and the article doesn't seem to have any mention of them.


204.38.203.104 03:18, 13 September 2007 (UTC)

I totally agree. AS a mirror image twin i find it appalling that there is no mention of this variation. I think that this community should tackle this problem immediately! —Preceding unsigned comment added by 71.116.111.98 (talk) 02:40, 25 March 2008 (UTC)

7:14, March 24 2008 (rtmclar)----> please excuse the lack of proper punctuation. I don't use wikipedia that much and came across this for a school project.

[edit] photos again...

3 pictures of babies? THREE? That strikes me as completely superfluous. Sorry if I'm raining on someone's parade here but most babies look pretty similar, twins or not. Substituting in one or two pics of older twins (maybe one pair in their teens, another pair who are adults for example) wouldn't go amiss. - random anon —Preceding unsigned comment added by 82.25.149.50 (talk) 15:10, 17 October 2007 (UTC)

[edit] Photo

I like this article, and as I am adult identical twin, I might try and convince my sister to let a photo of us be in this article. However, I need to think about it and she might say no...If we decide to do it, I'll post it here first for discussion. Cheers. Dina 17:30, 19 October 2007 (UTC)

My sister has agreed, now we just have to find or take a photo that satisfies both our vanity and the purposes of the article... Dina 18:49, 19 October 2007 (UTC)

Sounds good to me. Go for it. : Albion moonlight 06:14, 20 October 2007 (UTC)

[edit] A zygote is an embryo?

In the part about semi-identical twins, it says that "the coalesced eggs undergo further cell duplications developing as a chimeric zygote". As far as I'm in touch with the terms, it wouldn't be a zygote, but an embryo already, the reason being that, as far as I know, the latter is composed of more cells while the former is only one. The blastomere article, however, equates the zygote and the embryo, saying that an embryo can be called a zygote, whilst I think that the truth is that the zygote can be called an embryo - but not all embryos are zygotes (and thus the blastomere isn't a zygote anymore, nor compose one). That's what I think to be the correct definitions, anyway, but I'm not an expert in the subject, so I might be just "making it up". Notwithstanding I've tried the simple "define:zygote" on google, and a few definitions seem to corroborate mine: "A fertilized egg before cell division (cleavage) begins." (www.dhmc.org); "Fertilized egg or [...] that will cleave to form an embryo." (dictiongloss.com) --Extremophile (talk) 04:35, 26 November 2007 (UTC)

I tagged that section with an expert tag. perhaps that will attract someone with the right answer. Thanks for the question. This article has been vandalized quite a bit over the past 3 or 4 months. : Albion moonlight (talk) 07:25, 26 November 2007 (UTC)

According to my copy of Vander, Sherman, and Luciano's Human Physiology (10th edition, Widmaier, Raff, and Strang) a zygote is a "newly fertilized egg", and a conceptus is "a collective term for everything ultimately derived from the original zygote (fertilized egg) throughout the pregnancy". It goes on to say "Soon after the conceptus reaches the stage of a blastocyst, by which point the cells have lost their totipotentiality and have begun to differentiate. The blastocyst consists of of an outer layer of cells, the trophoblast, an inner cell mass, and a central fluid-filled cavity. During subsequent development, the inner cell mass will give rise to the developing human - an embryo during the first two months and a fetus after that" From this, we can see that an embyro is a zygote that has undergone cell division and differentiation. In the case of chimeras, I do not believe it would be correct to refer to them as a single zygote or embryo, because they are in fact two different organisms (as the term is defined using DNA to differentiate). Raul654 (talk) 03:02, 27 November 2007 (UTC)

Note - I've tweaked that section accordingly. Raul654 (talk) 03:16, 27 November 2007 (UTC)

And thank you very much for doing so. : Albion moonlight (talk) 07:33, 27 November 2007 (UTC)

[edit] Results of new study: Identical Twins do not have EXACTLY same DNA

According to an article published today in the American Journal of Human Genomics, researchers studied 19 pairs of identical twins to discover that there are very slight differences in every pair of identical twins. They have the same DNA, but in each pair, there were copies or deletions of some segments of DNA, which is why one twin could get a genetic disorder that the other does not.

I think this new finding should be read over and should be mentioned in the line that says that they have the same exact DNA.

Phenotypically Concordant and Discordant Monozygotic Twins Display Different DNA Copy-Number-Variation Profiles

Your thoughts welcome -JasonSpradlin82 (talk) 17:19, 15 February 2008 (UTC)

[edit] Chances of more Multiples??

I am a mother of fraternal twins, and I don't fall under any of the factors that predispostion women to get pregnant with twins. Im not West African, I'm only 23 (19 when I got pregnant with them) and I haven't ever had any previous births. There aren't any closely related twins to me in my family. I want to know if anyone has any idea of the likelyhood of carrying mulitples again.. My twins were born preemie, but otherwise healthy, and I am in good health. My husband and I want to have more twins, and I want to know if there is a good chance I might concieve them again naturally, like I did the first set. They are three now and I want more twins!!68.212.17.96 (talk) 03:26, 18 February 2008 (UTC)

You should consult with your OB/GYN. Wikipedia's editors are not qualified to give medical advice. Nandesuka (talk) 05:39, 18 February 2008 (UTC)

[edit] twins and genetic research

The two paragraphs right at the end of the monozygotic twins section seem to be about general genetic research, rather than anything specifically to do with twins. Unless I'm not reading it right?

That section also repeats itself a little on the 'identical DNA' front. —Preceding unsigned comment added by 86.175.65.65 (talk) 14:33, 17 April 2008 (UTC)

Since no one has objected, I'm removing the section. It's pasted here below if anyone would like to revise (including the spelling error(s) and style problems) and relate more directly to twins. I get that genetic studies and twins are related, but so are many other things (e.g. we don't need a link to Watson and Crick here).Mjgilbert (talk) 17:42, 14 May 2008 (UTC)


A large number of SNPs spaced throughout the genome have been identified recently in a large project called the HapMap project[1][2]. The usefulness of the HapMap project and SNP genotyping and their relevance to society was covered in the 27 October 2005 issue of the leading international science journal Nature (Fig 3).

A large number of genes have been identified that contribute to human disease. These are avaialble from the US National Library of Medicine, which has an impressive range of biological science resources available for free online. Amongst these resources is Online Mendelian Inheritance in Man - OMIM that provides a very, very comprehensive list of all known human gene mutations associated with, and likely contributing to, disease. Each article at OMIM is regularly updated to include the latest scientific research. Additionally, each article provides a detailed history of the research on a given disease gene, with links to the research articles. This resource is highly valuable and is used by the world's top science researchers.