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Allo- and Autozygous[edit]

I added the section about allozygosity and autozygosity, as they were requested articles. I forgot to sign in though... I do that a lot >_< Silver 01:52, 15 March 2007 (UTC)

There must be a different way to describe the difference between these terms - all alleles of a single gene are related by descent. Dr d12 20:10, 15 March 2007 (UTC)
Well, life on this earth is related through a common descent, yet we can segregate. I think the problem and difference is in evolution of an entire species, there is speciation. We can see that two previously related animals can no longer mate. I think what we need to describe here is like… if a new species of horse and a new species of donkey both evolved wings. Since their common ancestor did not have wings, this is an example of convergent evolution. What we have to describe is something like this:
Allozygosity: ancestor allele 1 does not express trait A, and gives rise to allele 2 and allele 3, neither of which express trait A. Now, if allele 2 mutated to have trait A and allele 3 mutated to have trait A, those alleles are allozygous for trait A.
Autozygosity: ancestor allele 1 has trait A, and gives rise to allele 2 and allele 3, which have differences and as such are not the same allele, still have trait A, allele 2 and allele 3 are autozygous for trait A.
Now… I just have to figure out how to make that eloquent… Silver 20:20, 16 March 2007 (UTC)


I believe that there is a nullizygosity where both alleles of a gene or chromosome are deleted or missing. It has implications in many cancers. cobalt 16:35, 20 June 2007 (UTC)

Nullizygous seems to be a fusion of the words homozygous and null (complete loss of function or gene knockout). For example, a p53 nullizygous mouse is homozygous mutant for a null allele of p53. Dr d12 (talk) 02:07, 25 February 2009 (UTC)

Split into three[edit]

Although the three subjects listed in the title are inter-related, they are quite simply that - three separate subjects. As such, they should clearly have three separate articles, as they have in other language versions of Wikipedia. No-one is going to search for any of these items using the current title, and although redirects exist, this is a lousy way of going about things. It also looks like sonmeone has done a copy and paste move of the article from elsewhere, rather than following Wikipedia policy and GFDL rules by doing a merge of page histories. In other words, it looks like someone has stuffed up majorly with this one. Grutness...wha? 00:59, 1 January 2007 (UTC)

I'm somewhat new here, so I don't know the proper procedure for doing this, but I strongly second this. The current setup is absurd. Builderman 03:16, 10 January 2007 (UTC)
I also agree. The page now has other sections added to it beyond the three in the title. cobalt 16:37, 20 June 2007 (UTC)
Support as per the past three. Lunakeet 16:58, 7 May 2008 (UTC)

Page merge[edit]

This was a Full-content paste merger of several pages (homozygote, hemizygote and heterozygote - and their relatives homozygous, heterozygous and hemizygous) after the instructions on Wikipedia:Merging and moving pages - see the page history. I know the title is long but "Zygosity" doesn't work (twins) - if you search for hemizygote (...) here you come. Wikipedia does not need a separate entry for every concept in the universe. Do you also think that Ploidy should be split into separate pages for haploid, diploid, polyploid, or that Muller's morphs is better covered in 6 or 7 articles called Amorph, hypomorph, hypermorph, antimorph, and neomorph, null, dominant negative... These are each simple concepts that can be described more efficiently in groups. Dr d12 15:55, 1 January 2007 (UTC)

The original title of the merged page ("Homozygote, Heterozygote and Hemizygote") has been updated to "Zygosity" with an explanation of its application to genetics and twins. This was suggested by User:Kraikk in "my talk" User:Dr_d12. Dr d12 18:30, 9 January 2007 (UTC)
If anyone is interested, here are the talk pages from the merged pages (Hemizygous/hemizygote talk page didn't exist).
(1) Talk:Homozygote:
"Is homozygote and hemizygote the same? If no, what's the difference? massa 03:03, 10 August 2005 (UTC)
It's not. I've edited the article and reverted the redirect. I'm surprised incorrect information lasted so long.
Toph99 02:00, 16 August 2005 (UTC)"
(2) talk:Heterozygote:
"simple analysis: pair of allele for a characteristic are different e.g. Hh"

I think that it shouldn't be redirected form Heterozygosity as that is a measure of genetic variation as opposed to zygosity.

Confusing wording[edit]

This is not a subject I'm very familiar with, but I suspect the wording could be much improved. The opening paragraphs appear to give conflicting definitions of zygosity. The word, if I understand correctly, can be used in several senses and applied to (1) loci, (2) genes, (3) organisms, (4) genomes, (5) chromosomes, (6) twins, (7) alleles, and perhaps other things. The full range of its uses should be mentioned in the opening sentence.

I suspect, too, that zygosity can be used generally to refer to all the qualities expressed by adjectives ending in -zygous and nouns ending in -zygote.

Finally, the sentences beginning with a term followed by "is when" really ought to be reworded. That's no way to characterize a noun. D021317c 09:40, 5 October 2007 (UTC)

I agree, the wording seems a bit confusing, especially around the beginning. Isn't it supposed to say that zygosity is the difference between alleles? Alleles are the variations of a gene, so when I think variations between genes, I think genes on different loci. Not sure how correct I am, I'm still taking introduction to biology. Blafreniere (talk) 01:48, 4 November 2010 (UTC)

Split article[edit]

I agree with what other editors on this talk page have allready stated. The terms homozygous, heterozygous and hemizygous require three seperate articles. At the very least section redirects. I guess it just needs someone to be bold.Sting_au | Talk 01:30, 16 November 2007 (UTC)

simple examples would help[edit]

I think clarity would be helped tremendously if some simple examples were added. Like how it would be when combining different eye colors or something. Because as it is now, there is a lot of jargon without much connection to how these things come to people via the media. I would do it myself if I would feel qualified. (talk) 09:00, 8 May 2008 (UTC)


I've just completed a major re-work of this article. In addition to fixing mechanics (grammar, punctuation, etc), I tried to organize the information better and make it more readable and understandable for people who are not familiar with the topic. In the course of doing so, I've made a couple of changes that might be questioned, so I'll address them here.

First, I completely changed the section on the terms autozygous and allozygous, including removal of any mention of convergent evolution. I could be wrong, but if I understand correctly the two are not related. Convergent evolution results in emergence of similar structures, called analogous structures, in completely different types of organisms that do not share a common ancestor (or at least not one who passed on the trait in question). This is completely different from emergence of similar structures, called homologous structures, resulting from a shared ancestor that passed the trait to two or more branches of the evolutionary tree. Allozygotic homozygosity (wow, there's a good tongue twister!) can, I suppose, result from convergent evolution in some cases, but I really think it's a stretch to connect it as firmly as it was in the previous version of this article. But that's just based on my own reasoning in an attempt to make logical connections among a wide array of diverse facts that I know. If I've made any mistakes either here or in the article, I'd love to discuss it.

Second, I completely removed the section called "Inheritance of traits". As far as I could tell, everything that was in it was either (1) already covered elsewhere in the article or (2) not particularly relevant to this specific topic. Again, if anyone disagrees I'll be happy to discuss a compromise.

Third (and far less controversial, I'd guess), I added a section for nullizygosity. I know very little about it but I wrote what I do know, and I added a tag for expansion of the section.

In addition to those things, I thought I'd throw in my two cents about splitting the article. I'd be pretty strongly opposed to doing so because I just don't know that there's enough to say about any individual term within this article to warrant the splitting. I think that any article that's written about an individual term from this one is going to end up being a perpetual stub. I feel so strongly about this that if no one disputes it within a week or two I'm planning to remove the "split" tag. As always though, if anyone disagrees I'm happy to discuss it.

And finally, I'd just like to point out that the article still has zero sources cited. I'm a pretty decent writer and copy-editor but I really suck at sourcing so I'm going to leave it like this for now. However, I'm hereby issuing a plea for anyone who is able to do so to add a few reliable sources. I think it's a great article and I believe that all the information is good, but I also believe that we need to have a foundation for the information we place here. I appreciate anything that can be done to help. -- edi(talk) 15:51, 24 January 2009 (UTC)

P.S. I just noticed the "technical" tag at the top of this page. I think I've improved that aspect a fair bit, but that may just be my perception. I'd appreciate hearing from others to know whether the tag should be removed or whether more work is needed on the technical language. -- edi(talk) 16:03, 24 January 2009 (UTC)
I'm going to give one last notice just to be absolutely sure that I've at least attempted to find consensus: As I mentioned above, I think the "split" and "technical" tags can be removed from this article, and I plan to do so if no one objects in the next few days. If anyone disagrees, I'm happy to discuss it. Thanks. :) -- edi(talk) 22:29, 4 February 2009 (UTC)
Okie doke, no response at all, so both tags have been removed. If anyone wants to discuss this with me, I'll be happy to talk about it, no problem. Thanks. :) -- edi(talk) 22:29, 9 February 2009 (UTC)

Eukaryote bias[edit]

Since the bias here is painfully obvious, I trust that no one will object when I edit the lead to read:

Most organisms have a single circular chromosome...

Right? Hcobb (talk) 21:32, 17 June 2010 (UTC)

Assessment comment[edit]

The comment(s) below were originally left at Talk:Zygosity/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

rated top as high school/SAT biology content - tameeria 15:15, 17 February 2007 (UTC) This article needs references. Homo- and heterozygote is a completely different concept from mono- and dizygotic. I think the distinction needs to be made clearer, possibly by splitting the article. - tameeria 20:38, 18 February 2007 (UTC)

Last edited at 20:38, 18 February 2007 (UTC). Substituted at 11:20, 30 April 2016 (UTC)