Talk:Consanguinity

message: It should be noted here that the chart doesn't follow the "intuitive fractions" people often employ when discussing this: siblings equal 100%, parents and children 50%, grandparents 25%. The up a step down a step makes sense for cousins and aunts and uncles (the latter technically 50% if they are 100% to mom or dad) but it doesn't seem right for siblings. If anything they should be ranked zero--as close a genetic match to us as is possible. Marskell 15:29, 29 August 2005 (UTC)
replies: text: I think that you're right, siblings should not be less related than parents, however, I don't know if they more. -- Kjkolb 09:23, 22 October 2005 (UTC)
thread_title:  Thoughts 

message: I'm pretty sure that the 4th degree of consanguinity is between first, not fourth cousins
Actually it is.
Ego -> Parents -> Grandparents -> Aunt/Uncle -> Cousin
--Sven Lotz 11:42, 14 July 2007 (UTC)
thread_title: Degrees of Consanguinity

message: I came here looking for info on aunts, uncles, nieces, and nephews. Some or all of those words are redirected to the related article Cousin, but that article is very light on covering them. Looking at Cousin and this article and their talk pages, it seems that both articles are pretty weak. I think somebody needs to come in and clean house. Sibling could use a bit of housecleaning, too. Lou Sander 22:06, 9 February 2007 (UTC)
thread_title:  Expert attention needed 

message: I've added a section on the increased risk of autosomal recessive disorders in consanguinous relationships.
--Mike Burden (talk) 11:51, 27 April 2008 (UTC)
thread_title: Genetic Disorders

message: The table shown in the article is a table of relationships, not a table of consanguinity. A table of consanguinity shows the degree of relationship between two individuals, not just the name of their relationship to one another. For example, a person is related in the second degree to his/her grandchildren.  A person is also related in the second degree to his/her siblings.  I've added an external link to a real table of consanguinity. As there are two ways to compute degrees of collateral consanguinity-- by civil law and by canon law (church)-- there need to be two tables of consanguinity shown in the article.  —Preceding unsigned comment added by 12.76.129.17 (talk) 15:36, 22 August 2008 (UTC)
thread_title:  Table of CONSANGUINITY needed 

message: The page would benefit from a discussion of how consanguinity is applied under common law and statute beyond probate.  For instance, how it is used for determining prohibitions on nepotism.  Also, how consinguinity is applied to a spouse and the spouse's relations.  AusJeb 15:46, 10 December 2008 (UTC)
thread_title:  Legal Application needed 

message: The genetics section needs a complete rewrite, because it ignores the crucial issue that genes are inherited in blocks (as chromosomes). So for example, the boundary of F >= 0.0156 for consanguinity isn't arbitrary. It is the boundary at which the probability fallss below 0.5, that a male and female parent would share an identical chromosome (modulo any intervening mutations) that they could pass to a child. There are other similar errors in this section. This has ramifications throughout the article, wherever it talks of percentage of shared genes - it should be talking about probability of sharing a  gene (the difference is minor up to second degree, but becomes increasingly important for more distant relationships). 
By the way, this is one reason that a technical genetics section continues to be needed in this article - there's too much misunderstanding of these issues 'out there', it's not hard to find talk of miniscule levels of shared genetics between fourth cousins. 
If no-one objects in the meantime, I'll put some effort into tidying up these issues in January when I have some free time.  Urilabob (talk) 03:39, 20 November 2010 (UTC)
replies: text: due to crossovers chromosomes are not inherited unchanged.  For example a woman has two Xs.  She gives an X to her daughter.  She doesn't give one of her two Xs; she gives an X made from parts of her two Xs.  — Preceding unsigned comment added by 68.34.239.79 (talk) 06:08, 29 June 2012 (UTC)
thread_title:  Genetics needs a complete rewrite 

message: In 1215 the Fourth Lateran Council made what they believed was a necessary change to canon law reducing the number of prohibited degrees of consanguinity from seven back to four.[8] The method of calculating prohibited degrees was changed also.[9] Instead of the former practice of counting up to the common ancestor then down to the proposed spouse, the new law computed consanguinity by counting back to the common ancestor.[9] <...> ...the need for dispensations was greatly reduced.[10]  
So we have a contradiction...
Before 1215: 7 degrees prohibited and "Roman" calculation rule. In this case 3rd cousins can marry (8th degree).
After 1215: 4 degrees prohibited and "Germanic/Canonical" calculation rule. In this case 3rd cousins may not marry (4th degree).
The method of calculation was not changed in 1215. "Germanic/Canonical" calculation rule was adopted earlier.  — Preceding unsigned comment added by 213.87.142.15 (talk) 10:22, 10 September 2013 (UTC)
thread_title:  [[Consanguinity#Religious and traditional law|Religious and traditional law]] 

message: The percentages do not seem correct.  All direct male lines share 50% dna from the y chromosome.
The calculations are different for females.
This page does not reflect that in the chart.
I like to say "Boys are daddy (Y) and a little bit of pot luck (X).  Girls are pot luck (X)."
It says 50% of X comes from the father and 50% from the mother given.  There are dominant, co-dominant, recessive, etc., i.e. my sister has more British and Irish than my mother and I have less than my mother or something like that.
Looking at our chromosomes, I received an email where the individual believed my younger sister to be my aunt and my mother's sister, not mine.
My sister shows regions that I do not because she may have one more marker consistent with that group making her look like and member, whereas I may lack one marker.
Some markers she did not get at all from our father and I received all of his that were similar, whereas she received none, so I look consistent with 4 other genetic groups that she does not appear to belong to.
Her genetic matches are thousands more than mine.
It's not nearly as cut and dry.
However, it may be possible to say more about a direct male line.
It used to be expected that if a woman was widowed an unwed brother was expected to wed the widow.  That brother could be more than a 50% dna match depending on which x chromosomes that received.  Not to say that two brothers are the same or that the brother would even make for an agreeable marriage.
My youngest sister and I are very different individuals.  Growing up people said they didn't even see a familial resemblance.
However, she does match a good bit of both family trees, but there are individuals that she does not tie to genetically for some roll of the dice reason.
There are only two finite combinations of the same two chromosomes.  If a married couple could realize all combinations + 1, they could have identical children that are not twins.
I annoy people when I say the human race is finite.  I suspect that mutations are not common enough for this not to be the case.  And the idea of mutating dna probably means there will be a coupled shift or counter posing mutation that would cause a whole other series of issues.
However, I suspect that there is a purpose for all markers.  Some people may have opinions on which are desirable or undesirable or combinations thereof.  However, I doubt anyone is really smart enough to understand all of that.  However, surely there are those who taut they do. :-))  — Preceding unsigned comment added by 67.245.53.92 (talk) 09:04, 16 April 2017 (UTC)
replies: text: Your observations are incorrect. The Y chromosome accounts for less than 1% of the total base pairs in the human genome in men. See here. Nearly all the rest is diluted by 50% in every human reproduction. Males generally inherit 100% of Y-DNA from their fathers. Chris55 (talk) 15:34, 12 May 2017 (UTC)
replies: text: This is not a page for general discussion of the subject.  Please discuss concrete improvements to the article, based on reliable sources, discussed in light of the policies and guidelines. Thanks. Jytdog (talk) 16:42, 12 May 2017 (UTC)
thread_title:  Percentages 

message: This article states:
"...consanguinity table in which each level of lineal consanguinity (generation or meiosis) appears as a row..."
Is the parenthetical remark correct? Does each level of lineal consanguinity equal generation or meiosis, especially the latter, which has to do with chromosomes? If there is such a direct relationship, please explain how and give a source.
I couldn't look into this too much because my real-life limitations were acting up, so all I could do is post these questions here. Thanks in advance for your consideration of these questions! Geekdiva (talk) 02:00, 13 October 2018 (UTC)
thread_title:  Level of lineal consanguinity = [[meiosis]]? 

message: Various IPs (presumably the same editor) have made multiple attempts  to rewrite the Average DNA shared table in the Genetic definitions. I think it makes more sense to leave the table as is, with the relationship first and then give the average DNA shared. I assume that readers will be looking at the table to determine what the average degree of shared DNA is for a particular relationship (say between first cousins: 12.5%), rather than saying, "I wonder what relationship has 5.46875% shared DNA?" and finding that it is  a "3.5-tuple-2nd cousin-pibling / 3.5-tuple-2nd cousin-nibling". I also agree with user:Craig Butz  and user:Erp that we should use the common terms used in the ref and that everyone knows rather than such terms as "pibling" and "nibling". 
If there are useful missing entries that need to be added to the table that's fine. Source them and add them, but let's not add such incomprehensible oddities such as "sesqui-1st great-cousin-pibling / sesqui-1st great-cousin-nibling" Meters (talk) 03:30, 26 October 2019 (UTC)
replies: text: Multiple IP blocks have not stopped this. Page protection is likely next. Meters (talk) 22:21, 4 February 2020 (UTC)
replies: text: I've removed a lengthy talk page addition on this by yet another IP from Brazil as WP:BLOCKEVASION of .   Meters (talk) 04:13, 18 February 2020 (UTC)
thread_title:  Average DNA shared table 

message: An editor has identified a potential problem with the redirect :Consanguinity (in Canon Law) and has thus listed it for discussion. This discussion will occur at Wikipedia:Redirects for discussion/Log/2022 March 12#Consanguinity (in Canon Law) until a consensus is reached, and readers of this page are welcome to contribute to the discussion.  Veverve (talk) 13:06, 12 March 2022 (UTC)
thread_title:  "Consanguinity (in Canon Law)" listed at [[Wikipedia:Redirects for discussion|Redirects for discussion]] 

message: Person X's siblings, the parents of X, and the direct offspring of X all share on average 50% DNA with X, and thus they all have the same degree of consanguinity with X. The "Table of Consanguinity" displayed to illustrate the article has erred on this point, and thus many of the numbers in the chart are wrong. Compare with the CC-chart here, which is correct: . 
This seems like a fundamental error, and I think that the chart should not be used without this issue being fixed. ––St.nerol (talk) 17:44, 19 April 2022 (UTC)
replies: text: I think the table in the intro is using the legal definition (US at least).   See for instance  where "Brothers/Sisters - Half-Brothers/Half-Sisters - Grandchildren - Grandparents" are second degree.  What it does need is a proper reference. --Erp (talk) 04:00, 5 May 2022 (UTC)
thread_title:  The numbers in the chart are off