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Werthead

The Lyanna + Rhaegar = Jon Thread (Part VI)

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[quote name='Szar' post='1644593' date='Jan 11 2009, 13.46']That's an extreme oversimplification, and not correct.

A has 40% damaged recessive alleles. B has 20%. Let's say just for the sake of argument that A is the result of incest and B represents the general population.[/quote]

Huh? Why on earth would an inbred person have _more_ damaged allels, percent-wise in their gametes? Inbreeding doesn't mutate your genes. It only makes it more likely that an offspring is going to be homozygous for one or more damaged recessive allels, with resultant negative consequences.
This effect was actually used in agriculture and even in animal husbandry to a degree - 2 unrelated strongly inbred lines, when crossed, give unusually vigorous and robust offspring.

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[quote name='Maia' post='1644783' date='Jan 11 2009, 21.46']Huh? Why on earth would an inbred person have _more_ damaged allels, percent-wise in their gametes? Inbreeding doesn't mutate your genes. It only makes it more likely that an offspring is going to be homozygous for one or more damaged recessive allels, with resultant negative consequences.
This effect was actually used in agriculture and even in animal husbandry to a degree - 2 unrelated strongly inbred lines, when crossed, give unusually vigorous and robust offspring.[/quote]

When did I say it mutated your genes? They likely have more damaged recessive alleles because of their parents. I should think it's fairly obvious. Maybe I'm wrong, it's been a while since I was in biology...

Okay, basics. I'm going through this more for my benefit than for yours, so bear with me.
Let's say you have a person with Aa in one gene. That person has children with someone who has Aa in that same gene. The chances are aa (25%), AA (25%) and Aa (50%). One in four children has no dominant allele, and if the recessive allele is damaged in both parents, the child is deformed in some way. That child has one more damaged allele than the child with Aa, and two more than the child with AA.

This likely happens in more than just one gene when it happens through incest, as both parents have similar genes. If it doesn't happen in the first gene, it likely does so in the next, or the next, or the next. (Let it be said that incest produces children with pure positive genes as well, especially if the parents have said qualities in signficant quantities. It's just rare because damage happens very easily to genes.)

So they have some amount of damaged recessive alleles with no healthy alternative. Assuming the child grows to adulthood and have children of their own, they impart their own damaged alleles onto their children. Even if their partner has fully healthy alleles, the children will receive recessive damaged alleles. Thus, they have more damaged recessive alleles than the average person who has not had incest among their recent ancestors.

Because they are recessive, they may never suffer for it. But they can impart said deficiencies unto their children, if their partner has damaged recessive alleles as well.

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[quote name='Maia' post='1644470' date='Jan 11 2009, 08.15']Sorry, but that's nonsense. You only get one set of genes from each parent. The danger of inbreeding is that chance of 2 damaged recessive allels meeting is higher if parents genes come from the same source, nothing else. So, yes, a single outbreeding _does_ completely undo bad effects of previous inbreeding for the resulting individual.[/quote]

My own understanding of genetics isn't sufficient to argue; I'll let those who know their stuff hash it out.

I will undermine my own point, though, by looking back at Targaryen history. The two Targaryens who married outside the family were Daeron II and Rhaegar. We don't know how Rhaegar's children would have turned out, but from what we've seen Daeron's seem to have been free from the taint.

Now, the madness surfaced again in Daeron's grandchildren. Aerion was crazy, Valarr maybe too. I'm not sure if all of Daeron's children married in the family. Baelor probably did, but was there another sister for Maekar? If Maekar married outside the family and still begot Aerion, a certified crazy, then that would seem to add credence to the madness being possible in Jon, despite Lyanna's blood. So anyone with better memory for Targaryen lineage know who Maekar's wife was?

I also don't know that GRRM will confine himself to modern genetics; if he wants Targaryen blood to behave a certain way, it will.

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Here is the problem with your equation Szar unless I misunderstood you. The probabilities you gave would hold true if both parents had heterozygous(Aa) genes. As far as we can tell from the Stark genepool they have had no history of madness hence their genes for that specific trait is homozygous dominant(AA). Also according to what we know Rhaegar may have been a bit odd but definitely not mad so he had the heterozygous(Aa) gene. From this we can conclude that ALL their offsprings will be born without the madness trait. Their kids will have 50/50 chance of getting AA or Aa gene so there is no way Jon is mad. It is also possible to completely wipe out the madness trait from their gene pool if only the kids with homozygous dominant(AA) genes survive and reproduce.

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[quote name='Szar' post='1644829' date='Jan 11 2009, 17.18']Even if their partner has fully healthy alleles, the children will receive recessive damaged alleles. Thus, they have more damaged recessive alleles than the average person who has not had incest among their recent ancestors.[/quote]

There is your mistake. You seem to think that inbred indivuduals would have more _different_ damaged allels. But they won't, not unless there are unrelated mutagenic factors at work. They would have the same percentage of damaged allels as everybody else _but_ there would be a higher probability of a child getting a matched pair of them and suffering for it.

Oh, and everybody has damaged recessives, of course. They aren't produced by inbreeding - they are in us all.

Re: Targs - one of Daeron I's children was mad. IMHO, Targ madness doesn't seem to depend on inbreeding all that much and maybe they keep it because there is some survival advantage in doing so. Certainly, when one looks at RL mad tyrants/great leaders, it seems that certain form of madness is conducive to amassing lots power and managing to keep it.

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[quote name='Maia' post='1644986' date='Jan 12 2009, 00.07']There is your mistake. You seem to think that inbred indivuduals would have more _different_ damaged allels. But they won't, not unless there are unrelated mutagenic factors at work. They would have the same percentage of damaged allels as everybody else _but_ there would be a higher probability of a child getting a matched pair of them and suffering for it.[/quote]
If person X has aa and person Y has AA, and only aa are damaged, then X has two more damaged alleles than Y, assuming all other factors remain constant.

[quote name='Maia' post='1644986' date='Jan 12 2009, 00.07']Oh, and everybody has damaged recessives, of course. They aren't produced by inbreeding - they are in us all.[/quote]
Of course.

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[quote name='Piper' post='1644914' date='Jan 11 2009, 17.14']I will undermine my own point, though, by looking back at Targaryen history. The two Targaryens who married outside the family were Daeron II and Rhaegar. We don't know how Rhaegar's children would have turned out, [b]but from what we've seen Daeron's seem to have been free from the taint.[/b][/quote]
Nope. Daeron's third son was Rhaegel, who was "meek, mad, and mild". He and Aerys I were both married, definitely to a sister in Aerys' case.

Viserys I married a Hightower and an Arryn, and the result was the Dance of the Dragons...though that doesn't necessarily mean that Rhaenyra or Aegon II were mad.

Also Aegon III married a Velaryon as his second wife, who gave him Daeron I and Baelor the Blessed. Baelor has certainly been called mad by some.

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[quote name='Other-in-law' post='1645034' date='Jan 11 2009, 19.03']Nope. Daeron's third son was Rhaegel, who was "meek, mad, and mild". He and Aerys I were both married, definitely to a sister in Aerys' case.

Viserys I married a Hightower and an Arryn, and the result was the Dance of the Dragons...though that doesn't necessarily mean that Rhaenyra or Aegon II were mad.

Also Aegon III married a Velaryon as his second wife, who gave him Daeron I and Baelor the Blessed. Baelor has certainly been called mad by some.[/quote]

Good stuff. I guess that means we can ignore real world genetics and conclude that it would be possible for Jon to have Targaryen madness if he was the son of Rhaegar and Lyanna.

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I took the Targaryen madness\genius not as a product of imbreeding but the reason for it. That being said they still took brides from other Houses, Valyrons and Baratheons for a couple of examples. So they were not imbreeding every generation.

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Alright so I talked to two doctors that I work with regarding the possibility of Jon being mad considering the details we know about his possible parents and they both agreed with my earlier post. Even though madness trait is't depended on a single gene(multifactorial) it will NOT be represented in the offsprings in R+L case. We know that Rhaegar wasn't mad and we know there is no history of madness in Stark family then we can conclude that Jon can NOT be mad. The only possibility is genetic mutation but that has no bearing on family history it just happens by chance.

So what I'm getting at is that even though I want to believe Jon is a Targaryen, I just don't see any hard evidence to back this theory. He doesn't have the Targ satin(silver?) hair, purple eye and most importantly he doesn't have the dragon dreams. Also given the fact that 4 out of 5 known Stark kids look more like Tully then Stark makes me think the Stark genes aren't that dominant at least nothing like Roberts genes. So I find it hard to believe that Lyanna's genes dominated all of Rhaegar's genes and none of Targaryen features are represented in Jon.

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[quote]o I find it hard to believe that Lyanna's genes dominated all of Rhaegar's genes and none of Targaryen features are represented in Jon.[/quote]

They are fantasy genes. They do what GRRM tells them to do

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Genetics isn't the only possibility for madness. It's simply the most likely in the case of the Targaryens -- due to the incest.

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[quote name='Ser Torgom The Armenian' post='1647626' date='Jan 13 2009, 17.48']We know that Rhaegar wasn't mad and we know there is no history of madness in Stark family then we can conclude that Jon can NOT be mad. The only possibility is genetic mutation but that has no bearing on family history it just happens by chance.[/quote]

This point was refuted by O-i-L, who pointed out that Daeron II (a Targaryen without the madness) and Myriah Martell (a non-Targaryen) had a mad son, Rhaegel.

Thus, analogously:

Rhaegar = Daeron
Lyanna = Myriah
Jon = Rhaegel

it would be possible for Jon to have the madness, given R + L = J.

Discussion of modern genetics is obviated by this example. Targ madness follows only one rule: GRRM says so.

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[quote name='Piper' post='1647799' date='Jan 13 2009, 20.54']Discussion of modern genetics is obviated by this example. Targ madness follows only one rule: GRRM says so.[/quote]

Well, I have to point out that in RL, inheritable psychic ilnesses don't require inreeding to be passed on to the offspring, so Jon getting Targ madness would agree with modern genetics ;) .

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Modern genetics don't count anyway.
Otherwise Joff, Myrcella and Tommen would be complete retards.
I think it's just random if a Targaryen gets the madness or not. That's what makes it so intresting ;)
But looking at Jons life so far I don't think he tends to madness.
And such a total change of character would not be very realistic.
So if R + L = J is true, I thikn Jon will be a great one :cheers:

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[quote name='General_Lee' post='1648525' date='Jan 14 2009, 16.19']Modern genetics don't count anyway.
Otherwise Joff, Myrcella and Tommen would be complete retards.[/quote]
"Otherwise"? I have seen nothing to point towards them [i]not[/i] being complete retards.

Joff certainly was.

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Even in highly inbred family communities, not everyone comes out mentally retarded and physically malformed. A single generation isn't particularly likely to produce more than a small fraction of notably affected offspring. It is a roll of the dice surely, especially for a family with previous examples of birth defects, but there is no reason why Joff and Tommen and Myrcella should be necessarily [i]expected[/i] to be disabled in any way. The otherwise recessive traits they received may even be good things.

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[quote]It is a roll of the dice surely, especially for a family with previous examples of birth defects, but there is no reason why Joff and Tommen and Myrcella should be necessarily expected to be disabled in any way[/quote]

I would agree if Cersei and Jaime were mere siblings but they are bloody twins!
Almost identical genome! That kind of incest should have lead to at least one of them being crippled (physically and/or mentally).
The dice must've rolled veeery luckily.

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[quote name='General_Lee' post='1649936' date='Jan 15 2009, 15.17']The dice must've rolled veeery luckily.[/quote]

Well, even if you roll on a 100-sided die, the chance of getting a 1 is still there. :)

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