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Post by Funky Kong on Dec 31, 2005 1:25:28 GMT -5
How close are half siblings genetically related?
Are they closer related than cousins?
Is this even the right forum for these questions?
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mb
New Member
Posts: 48
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Post by mb on Dec 31, 2005 4:25:16 GMT -5
Given that half siblings would share the same mother or father, obviously they are more closely related (sharing more of the same genes) than two cousins would be... Do the math.   |
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mb
New Member
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Post by mb on Dec 31, 2005 4:39:27 GMT -5
Actually, on second thoughts maybe I could be wrong. Perhaps it is possible for two cousins to both inherit (and therefore share) specific genes that could make them more closely related than two half siblings who inherit different genes from the shared parent.  Interesting question! ;D |
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Post by Funky Kong on Dec 31, 2005 11:14:03 GMT -5
Yeah, the cousins do not actually have to be more related, but i'm thinking if half siblings and cousins are somewhat equally genetically related. Like Y chromosome wise, it wouldn't be possible to tell two cousins whose fathers are brothers apart from siblings who only share the same father. Or what?
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Post by stella22 on Jan 2, 2006 19:50:04 GMT -5
First cousins share 1/8 of their genes with one another.
Full siblings share 1/2 of their genes.
Half siblings share 1/4 of their genes.
[ftp]http://www.genetics.com.au/factsheet/26.htm[/ftp]
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Post by Agrippa on Jan 2, 2006 20:33:34 GMT -5
Statistically.
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Post by greatness on Jan 2, 2006 21:24:33 GMT -5
yeah it depends.
If ur mom and dad r white. and ur half brother's dad is white, the same as urs, but ur mom is black, and ur cousin is all white. Then ur closer to ur cousin than to ur half-brother.
But it depends on who ur parent marries, and who ur cousin's parent that ur related 2 marries.
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Post by stella22 on Jan 3, 2006 19:08:56 GMT -5
From what I understand, a child is exactly 50% related to a parent. For siblings, they are roughly 50% related to one another, but this is just an estimate. What greatness is talking about seems to be the degree of inbreeding. Hmmm...now we could ask some difficult questions. If a mother and a father are full siblings, how related would their children be to one another? |
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Post by Agrippa on Jan 3, 2006 19:38:43 GMT -5
Thats what I meant, its just an estimate since siblings can have more or less genes in common whereas the secure relation to the parents is minimum 50 percent (if excluding the male-female difference with the y-chromosome).
In a related group, populations, all people are more related than random people from different parts of the world on which such theoretical estimations are rather based.
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Post by JoeyC134 on Jan 3, 2006 19:52:41 GMT -5
yeah it depends. If ur mom and dad r white. and ur half brother's dad is white, the same as urs, but ur mom is black, and ur cousin is all white. Then ur closer to ur cousin than to ur half-brother. But it depends on who ur parent marries, and who ur cousin's parent that ur related 2 marries. I'm guessing it kind of make sense because both your mother and father are probably genetically closer to your cousins parents since they're all of the same race. How related are cousins if their mothers are sisters and their fathers are brothers? |
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Post by Dienekes on Jan 3, 2006 22:18:06 GMT -5
Half siblings share 1/4 of their genes. Their relationship is the same as that between uncle and nephew and it is closer than between first cousins.
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