Genetic coding- 100% real world or fantasy for literature?

[The Fattest Leech]

This is a carryover discussion from this thread where this sub-topic went off the rails as far as topic to be discussed. So let's discuss how the author is using genetics in his own story as we seem to have come to crossroads of information.

A main point in that discussion by @Megorova is that George has mapped out the last 300+ years of genetics for most all of his characters in ASOAIF based on real world genetics. This goes beyond the basic literary telling of the simplified "Baratheons all have dark hair and blue eye" type of genetic mapping. The idea that Megorova puts to paper is this:

• So there is absolutely nothing that indicates, that Targaryens' bond with dragons is based on natural biology, rather it's something spiritual or pre-programmed. Seems more likely, that dragons were genetically modified, to obey to certain people and their descendants.
• Most likely first dragons, and their original masters were aliens, that came to Planetos on giant spaceship:
• It seems there are [as follows]...

1. In case if Aerion's mother was carrier of bb genes, Targaryen line:

2. In case if Aerion's mother was carrier of Bb genes, Targaryen line:

3. In case if Aerion's mother was carrier of BB genes, Targaryen line:

Daemion Targaryen + wife = Aerion Targaryen.

1) bb + bb = bb, 2) bb +Bb = Bb or bb, 3) bb + BB = Bb

Aerion Targaryen + Valaena Velaryon = Visenya, Aegon, Rhaenys.

1) bb + bb = bb, 2) Bb + bb = Bb or bb, or bb + bb = bb, 3) Bb + bb = Bb or bb

None of their three children were carriers of Bb genes, because if they were, then they wouldn't have had Targaryen looks. Thus even if there was a B gene in their father, it wasn't transferred further to Aegon I and his sisters.

Aegon Targaryen + Rhaenys Targaryen = Aenys I Targaryen.

bb + bb = bb

Aenys I Targaryen + Alyssa Velaryon = Jaehaerys I, Alysanne.

bb + bb = bb, bb

Jaehaerys I Targaryen + Alysanne Targaryen = Aemon I Targaryen, and 8 other children.

bb + bb = bb

Aemon I Targaryen + Jocelyn Baratheon = Rhaenys Targaryen.

bb + ? = bb

To identify what pair of genes Jocelyn had, let's go back to Baratheon line.

Daemion Targaryen + wife = Aerion Targaryen.

1) bb + bb = bb, 2) bb +Bb = Bb or bb, 3) bb + BB = Bb

Aerion Targaryen (1b2b or 3B4b) + mistress (? - 5b6b, 7B8b, 9B10B) = Orys Baratheon (BB or Bb).

Orys had dark hair and dark eyes, so he was either BB or Bb.

1b2b + 5b6b = bb <- not Orys' traits.

1b2b + 7B8b = 1b7B or 2b8b <- dark or light.

1b2b + 9B10B = 1b9B or 2b10B <- both dark.

3B4b + 5b6b = 3B5b or 4b6b <- dark or light.

3B4b + 7B8b = 3B7B or 4b8b <- dark or light.

3B4b + 9B10B = 3B9B or 4b10B <- both dark.

Based on this Orys' gene model could have been:

1b7B, 1b9B, 2b10B, 3B5b, 3B7B, 3B9B, 4b10B.

Orys Baratheon + Argella Durandon = child (father or mother of Robar Baratheon)

(1b7B, 1b9B, 2b10B, 3B5b, 3B7B, 3B9B, 4b10B) + (?) = (?)

Argella Durandon could be BB, Bb, or bb.

1. (1b7B, 1b9B, 2b10B, 3B5b, 3B7B, 3B9B, 4b10B) + 11B12B = 1b11B, 1b12B, 7B11B, 7B12B, 2b11B, 2b12B, 10B11B, 10B12B, 3B11B, 3B12B, 5b11B, 5b12B, 9B11B, 9B12B, 4b11B, 4b12B <- gene model of their child, in case when Argella is BB.

2. (1b7B, 1b9B, 2b10B, 3B5b, 3B7B, 3B9B, 4b10B) + 12B13b = 1b12B, 1b13b, 9B12B, 9B13b, 2b12B, 2b13b, 10B12B, 10B13b, 3B12B, 3B13b, 5b12B, 5b13b, 7B12B, 7B13b, 4b12B, 4b13b <- gene model of their child, in case when Argella is Bb.

3. (1b7B, 1b9B, 2b10B, 3B5b, 3B7B, 3B9B, 4b10B) + 13b14b =

etc.

Basically it doesn't matter which exactly genes out of b pool will pass to children, whether it will be 1b or 2b or 4b or 5b. What matters that in combination with any of B genes, the result will be dark coloring, and with combination of any one out of b pool genes, the result will be light coloring.

So I'll use just BB, Bb, or bb for further models, and later will write actual code.

Father of Robar (?) + Mother (?) = Robar Baratheon (?)

(BB or Bb or bb) + (BB or Bb or bb) = six BB, five bb, four Bb.

Robar Baratheon + Alyssa Velaryon = Boremund and Jocelyn Baratheons.

(?) + bb = (?), (?)

(six BB, five bb, four Bb) + bb = thirteen Bb, none of BB, 

Jocelyn Baratheon + Aemon I Targaryen = Rhaenys Targaryen.

(?) + bb = bb

However, there are certain others that seem to believe that our author is using his own, much more simplified, version of genetics for the literary intent of telling a story. This idea is mostly laid out here in this thread, but it was discussed in depth in another thread that I cannot find . What the other theory states is:

1. It seems as though the first born child to a mix of a Targaryen and non-Targaryen parents will conveniently always favor the non-Targaryen as far as physical looks, while the child may favor the Targ parent for personality and demeanor. Sometimes an exception child may have one Targ feature, but mostly they look non-typical-Targaryen.
   1. ADDING: After a little discussion it seems that having a non-Targargyen mother may have more of an effect on this theory. Maybe.
2. It is the subsequent children that most often take the Targ looks of skin color, hair color and eye color. This seems to occur mostly with just the second child, while the third, fourth, and so-on child can vary.
3. The typical Targaryen features are pale skin, silver, platinum, or gold hair and eyes in a variety of shades of purple, or light blue.
   • TWOIAF/ Targaryen Kings:  ...aquiline nose, fine features, silver-white hair, and purple eyes that bespoke his own Valyrian heritage. Source link.
   • TWOIAF/ Rise of Valyria: The great beauty of the Valyrians—with their hair of palest silver or gold and eyes in shades of purple not found amongst any other peoples of the world—is well-known, and often held up as proof that the Valyrians are not entirely of the same blood as other men. Source Link.
4. The current, Westerosi Targagryens are descended from Aerion Targaryen (son of Daemon) and Valaena Velaryon. The Velaryons as they are described as having the typical Valyrian looks; pale skin, pale hair, purple eyes. So in this case it makes it should have been Visenya who go the near indistinguishable Velaryon looks, and her personality is something else as well. All of the current Targaryens come from Rhaenys' line, which means they carry the stronger Targ looks just by that rule (plus the incest- another genetic rule that George is ignoring for his fantasy world). 

And this seems to play more of a literal importance to the story and characters, behavior, decisions, etc. Just a few examples we talked about in the other thread, but there are more:

• This idea is most significant to the current story with the main families (the only part that matters) and this also lets the author hide certain chosen ones in plain sight. This was the "need" to develop a simplified genetic code. Everything else is just basically collateral because they are not the focus of the story. Even main get a little plot armour.
• If you read the history of the Dondarrion's as pointed out in The Hedge Knight, you will see how the "flash of light from above" lightning saved the first Dondarrion, which lead to the beginning of that house. There is a literary purpose to all of this. This is also the same story that we see Valarr on page. There is a literary reason why these two events/info happen in the same short story. Valarr's Targ father looked like his Dornish mother (dark eyes and hair features), and he took a lot of shit for looking Dornish, as opposed to Targaryen. Valarr's mother was the Dondarrion side, and he takes more after her with the slighter build, brown hair (not Dornish dark), and the blue eyes (not his father's Dornish dark). There is a connection to the Dondarrion history, Valarr's streak of silver "saving" him, and death pays for life, etc, etc.
• Each person who has some sort of identity issue is like a walking personal sigil of themself. Even the Targs who had these issues always did something like reverse the sigils colors on house banners, or quarter their Targ sigil with something else (when theoretically the Targ sigil alone should have been the strongest). It helps tell the story.
• Brynden Bloodraven Rivers is my favorite example. He was given the chance to become legitimate, but instead he chose his own identity and gave himself his own sigil... and it matches his looks.
• At the Balticon dinner last year, I had the amazing opportunity to sit own with GRRM for an hour and a half an discuss my theories with him (amongst many other topics in our lives). When I presented him with this idea, and over the course of the time discussing it, he asked me several questions about "why" and "how did I find this stuff", gave me his typical answers like, and also confirmed a few things like some of the Targaryens who had an "interruption" to this normal flow of things, they were the ones out of balance and that is why they are "off" from the norm. This is something the author confirmed when we were discussing how it was the off-brand Targs that were the ones involved in the Dance of Dragons, which was a big fight about identity and who gets what.

• Steffon Baratheon does have the brand Baratheon looks- no Targ looks. He is the first born who takes after the non-Targ parent. His son, Robert I, also has the brand Baratheon looks, because the Baratheons are far more important to the story than the Estermonts are. We need this Baratheon brand to be important to the current story. This is how Stannis, Jon Arryn, and Eddard were able to parse out Cersei's children not being Robert's.

  The seed is strong, Jon Arryn had cried on his deathbed, and so it was. All those bastards, all with hair as black as night. Grand Maester Malleon recorded the last mating between stag and lion, some ninety years ago, when Tya Lannister wed Gowen Baratheon, third son of the reigning lord. Their only issue, an unnamed boy described in Malleon's tome as a large and lusty lad born with a full head of black hair, died in infancy. Thirty years before that a male Lannister had taken a Baratheon maid to wife. She had given him three daughters and a son, each black-haired. No matter how far back Ned searched in the brittle yellowed pages, always he found the gold yielding before the coal.

  • This last detail alone should show how real world genetics plays little to nothing in this fantasy story with dragons and human-tree hybrids. There is no way one genetic makeup would withstand the years of time and mixed breeding and still look undisturbed for centuries.

And a few more thoughts from the author about trying to break things down to the nth degree. He seems to be telling his own story, and the story comes first. Or not?:

• She [Brienne] is female.

  This is the Middle Ages. They don't know about DNA. Their knowledge of genetics revolves around theories about a person's "blood."

  If I start worrying about Brienne's chromosomes, the next step is trying to figure out the aerodynamic properties of dragons, and then the whole thing falls apart.

• I will now tell the story of what GRRM said when asked about the Stark children and their ability as wargs. He was asked if the trait of being a warg ran in the Stark family.

  "I don't know if I want to get into genetics - this is fantasy, not scifi" He replied.

• He acutally only said what I recorded above, he did not want to discuss genetics, but the children had it.

• My suggestion would be to put away the ruler and the stopwatch, and just enjoy the story.

So, any takers wanting to add new blood to this genetics discussion?

***ADDING: I will update here as new, viable information is added.

[The Fattest Leech]

Calling out to @Crona @maudisdottir @Megorova, and any and all who want to join.

This is the place for genetic discussion

[Crona]

Well, since its open..

It’s really hard to know exactly if real world genetics can be applied here since we don’t have a clear lineage on everyone. Such as Mariah Martell, I know that Megorova says her grandmother was Aliandra and Drazenko (even though, I can’t find anything that says they had children) but even then their children would have Bb then that child would have to marry someone but that up to interpretation because I don’t know who are Mariah’s parents. The child with Bb could have married someone from Dorne with BB and therefore Mariah could have BB. That would mean all of her children should have B along with Daeron’s should be either BB or Bb and they should have dark hair and dark eyes. Or Mariah’s parent could have inheriented Bb but it would be unlikely with someone who has BB.

Also, would incest be included in the real world genetics model? Because Craster has been with his daughters for a while, and I don’t recall any of them having any type of deformities?

[The Fattest Leech]

 

Quote

Also, would incest be included in the real world genetics model? Because Craster has been with his daughters for a while, and I don’t recall any of them having any type of deformities?

Nope, incest in ASOIAF follows its own rules as well. Daenerys (and most Targs), Craster's wives and babies babies should look like this if it followed real world genetics after so many, many repeated tree trimmings on the ol'family tree. http://image.tmdb.org/t/p/w1280/2PWIsx1YTYaracIEK0CHivC50t9.jpg

But Dany doesn't. She follows the same beautiful, ethereal elf beauty as the other Targs do.

Heck, Jon might even have a droopy eye from Rhaegar. But he doesn't. He is handsome.

They (Targs, Craster) would follow more along the lines of the Habsburg deformity traits and physical appearance if it followed real life. http://assets.rebelcircus.com/blog/wp-content/uploads/2017/07/charles-ii-of-spain_mainstory1.jpg

[Crona]

23 minutes ago, The Fattest Leech said:

 

Nope, incest in ASOIAF follows its own rules as well. Daenerys (and most Targs), Craster's wives and babies babies should look like this if it followed real world genetics after so many, many repeated tree trimmings on the ol'family tree. http://image.tmdb.org/t/p/w1280/2PWIsx1YTYaracIEK0CHivC50t9.jpg

But Dany doesn't. She follows the same beautiful, ethereal elf beauty as the other Targs do.

Heck, Jon might even have a droopy eye from Rhaegar. But he doesn't. He is handsome.

They (Targs, Craster) would follow more along the lines of the Habsburg deformity traits and physical appearance if it followed real life. http://assets.rebelcircus.com/blog/wp-content/uploads/2017/07/charles-ii-of-spain_mainstory1.jpg

That’s what  I thought too, if we use real genetic coding then incest would have to factor into it. (IMO) Because genetics is all about chance, a recessive gene can be present for a couple of generations and when in contact with another recessive could produce a child with different coloring. Sometimes two brown eyed individuals produce a green eyed child or vice versa. Most commonly though, the dominant gene (dark eyes and dark hair) will be the coloring of the children.

I honestly don’t think GRRM was thinking about genetics when he made his characters, just because the characters are too convenient, such as Jon looking like a Stark (depending on R+L) and Breakspear looking dornish, although he is in line to be king so the population feels he doesn’t look targ enough to be king. I think he picks what side the character should favor genetically based on their story.

[Pukisbaisals]

3 hours ago, The Fattest Leech said:

It seems as though the first born child to a mix of a Targaryen and non-Targaryen parents will conveniently always favor the non-Targaryen as far as physical looks, while the child may favor the Targ parent for personality and demeanor. Sometimes an exception child may have one Targ feature, but mostly they look non-typical-Targaryen.

I agree. I tried to explain this pattern in this thread on Targaryen heredity

First pregnancy affects the mother genes somehow andsecond child doesn't inherit her otherwise dominant traits. Maybe it can be explained as sort of microchimerism (our world phenomenon),  telegony  or even some transmitted infectious factor which switches maternal color genes off.

[Rufus Snow]

My knowledge of genetics is a little rusty, but I have concluded for myself that the rules of heredity which we accept in our world are not the same in Westeros, and that is basically down to the whole 'seed is strong' episode.

In our world, if Baratheon hair colouring is SO strong, it would have to be a dominant trait, so Baratheons born with a dominant + recessive gene pairing (Bb) would have the colouring but still pass the recessive (_b) to 50% of their children, thereby losing the dominance after a generation - which clearly doesn't happen. Ergo, in Westeros there is more to heredity than mere genetics.

All of which means we cannot use 'real' genetic reasoning to figure out who sired whom.... so there has to be more factors at play.

[Lady Dacey]

7 hours ago, The Fattest Leech said:

If I start worrying about Brienne's chromosomes, the next step is trying to figure out the aerodynamic properties of dragons, and then the whole thing falls apart.

 

7 hours ago, The Fattest Leech said:

"I don't know if I want to get into genetics - this is fantasy, not scifi" He replied.

 

7 hours ago, The Fattest Leech said:

This last detail alone should show how real world genetics plays little to nothing in this fantasy story with dragons and human-tree hybrids. There is no way one genetic makeup would withstand the years of time and mixed breeding and still look undisturbed for centuries.

YESSSS

there's something I'd like to add to the thread. I fully agree that real genetics has no place at all in Planetos. It's fantasy, a very good one at that, with its on rules.

I truly doubt any of the people proposing "genetic theories" of looks and abilities actually has studied genetics at all!! Their assumptions are very misguided and based on simple (and irreal) high school Mendelian Genetics. I've actually studied genetics in university, and it's just very different and much more complex than people seem to assume... really. In real life there's much to understand yet! I can tel you most inherited phenotical characteristics are very complex and determined by the interaction of several different genes that play different roles at supressing or enhancing one another, that's called a poligenic feature. Just for eye color for example there are at least 16 different loci (places where genes are located) involved! It's definitely not as simple a simple AA x aa = Aa. Not even close. That's the exception of how inherited characteristics work, not the rule.

It makes no sense to try and understand asoiaf inheritance under the light of real world genetics. 

[Lady Dacey]

4 hours ago, Pukisbaisals said:

First pregnancy affects the mother genes somehow andsecond child doesn't inherit her otherwise dominant traits. Maybe it can be explained as sort of microchimerism (our world phenomenon),  telegony  or even some transmitted infectious factor which switches maternal color genes off.

NOOOO!!! NO!! NO NO NO NO!

microchimerism or telegony would never affect the subsequent child of a mother. It's just not how it works... real genetics has no place in planetos, it's futile to try and explain inheritance in asoiaf with complex pseudo-scientific theories. It's fantasy and works as such. 

 

[LynnS]

3 hours ago, Rufus Snow said:

My knowledge of genetics is a little rusty, but I have concluded for myself that the rules of heredity which we accept in our world are not the same in Westeros, and that is basically down to the whole 'seed is strong' episode.

In our world, if Baratheon hair colouring is SO strong, it would have to be a dominant trait, so Baratheons born with a dominant + recessive gene pairing (Bb) would have the colouring but still pass the recessive (_b) to 50% of their children, thereby losing the dominance after a generation - which clearly doesn't happen. Ergo, in Westeros there is more to heredity than mere genetics.

All of which means we cannot use 'real' genetic reasoning to figure out who sired whom.... so there has to be more factors at play.

The problem that I have with Robert Baratheon only producing black hair/blue eyes is that we only have a small sample of his sixteen offspring to support that assumption.  Of his seven known bastards, only three of them are confirmed to have both these traits (Gendry, Edric,Mya); two are only confirmed to have black hair only (Bella, Barra - Bella's story is somewhat questionable) and the twins have no description in the text.  There are eight others who are not found at all, if you believe Maggy the Frog's prophecy.  If you are only looking for black hair/blue eyes; then that is all you will find. 

I'm also not sure that Lysa's account of Jon Arryn's drug induced fever vision is about physical appearance at all when he says "tell them the seed is strong, tell Robert his seed is strong."  This can be read as singular, specific to one particular offspring rather than all of his offspring.

I don't think the 'seed is strong' argument is about physical characteristics but rather, the importance of one of his offspring. 

In the symbolic langauge that Martin employs using myths and legends; the Night's King must wear a crown and I suspect it has the antlers of the horned lord, so important to the wildlings and the King beyond the Wall symbolism.   It's rather in your face that  Robert wears such a crown and his corpse queen is no other than Lyanna; always his dead bride.

I'm not sure that Martin's peculiar brand of genetics will provide any definitive answers to the parentage questions. 

I'll also point out that corns are seeds to quote Ravenous Readers.  So when that precocious bird, Mormont's Raven says that Jon Snow is the Corn King; what is Martin telling us?  Is Jon the 'seed' of a king?  

 

[Lady Dacey]

On 09/12/2017 at 4:58 AM, Crona said:

The child with Bb could have married someone from Dorne with BB and therefore Mariah could have BB. That would mean all of her children should have B along with Daeron’s should be either BB or Bb and they should have dark hair and dark eyes. Or Mariah’s parent could have inheriented Bb but it would be unlikely with someone who has BB.

You're all fixated in BBs and bbs and Bbs but not even real world genetics works like this! It doesn't, really... some characteristics actually have no dominance at all (the offspring will show a mix of the genitors characteristics, such as a pink flower descending for a red and a white one, a Bb who does not look like a BB!). Most characteristics are poligenic. Epigenetics play a big role we haven't yet figured out in activating or supressing genes, in such a way an offspring can manifest a phenotitycal characteristic that was muted for several generations...

[Angel Eyes]

I guess they don’t take grandparents into much account when they talk about appearance. Take a look at the Velaryon sons of Rhaenyra; they’re part Arryn from their mother’s side (Rhaenyra’s mother was Aemma Arryn) and their grandmother Rhaenys, mother of Rhaenyra’s first husband Laenor is part Baratheon (her mother was Jocelyn Baratheon). But nooo, they’re the kids of Harwin Strong, because they can’t possibly be Valyrian. They gotta come down with an attitude, acting all big and bad...

[Pukisbaisals]

1 hour ago, Lady Dacey said:

microchimerism or telegony would never affect the subsequent child of a mother. It's just not how it works... real genetics has no place in planetos

Genetics of Planetos doesn't have to be identical to real one.  Maybe telegony works in ASoIaF fantasy world in contrary to  real one. 

Inheritance of maternal hair and eye color is somehow blocked after first pregnancy.

To me, repressing off maternal traits is best and in most simple way explained by some infectious factor (targvirus). Sort of a simple switching maternal pigment genes off.

But possibly cells (blood) of first fetus stay in mother's body (thus it resembles  microchimerism) and even partially replace mother cells and second child inherits Targ traits both from his mother (in fact from his elder sibling) and father.

[Crona]

3 hours ago, Lady Dacey said:

You're all fixated in BBs and bbs and Bbs but not even real world genetics works like this! It doesn't, really... some characteristics actually have no dominance at all (the offspring will show a mix of the genitors characteristics, such as a pink flower descending for a red and a white one, a Bb who does not look like a BB!). Most characteristics are poligenic. Epigenetics play a big role with haven't yet figured out in activating or supressing genes, in such a way an offspring can manifest a phenotitycal characteristic that was muted for several generations...

Sorry, I haven’t read about genetics in a while just trying to make sense of the one posted. But  I think I did say that that two individuals that have Bb (brown eyed) could produce a blue eyed offspring because the offspring could be bb. And I thought that BB means brown eyes and Bb meant brown eyes too but Bb could pass the recessive b. 

And I agree that real world genetics cannot be compared to Planetos

[Ferocious Veldt Roarer]

No, I really really really don't think that GRRM had filled several sheets of paper with carefully calculated lowercase and uppercase B's before writing the story. I really didn't get the impression that that was what "A Song of Ice and Fire" was about. Did anyone? Seriously?

By the way, once upon a time, George has written a series of stories where the protagonist was "a humble ecological engineer", who invariably saved the day with his art of genetic manipulation. The author didn't seem to care, or even know, a great deal about genetics there, it was always just "Tuf started cloning and crossbreeding and a few weeks later, voilà!".

The genetics of ice and fire is just as simple - or, rather, nonexistent.

[Lady Dacey]

40 minutes ago, Ferocious Veldt Roarer said:

The genetics of ice and fire is just as simple - or, rather, nonexistent.

Perfect! I totally agree

[Lady Dacey]

1 hour ago, Crona said:

But  I think I did say that that two individuals that have Bb (brown eyed) could produce a blue eyed offspring because the offspring could be bb. And I thought that BB means brown eyes and Bb meant brown eyes too but Bb could pass the recessive b. 

I get your meaning and I can see the good intentions in everybody's work trying to make sense of it all, my point is: high school level biology and some googleing is not enough to understand how genes work. As I've stated before there are at least sixteen different genes involved in eye colour determination. That's why there are several different shades and it's not as simple as "two brown eyed people may have a blue eye offspring" even the real world. Genetics is a very very complicated subject and we don't yet know how inheritance works for most of human phenotipycal characteristics even in the real world. For real. I've studied it at university level. 

I really love science and I really love fantasy and I like sci-fi... but the world of asoiaf doesn't follow our 'genetic rules' or any set of specific rules for inharitance at all. Baratheons have a strong seed, Targaeryans not as much. Sometimes a child takes after the mother, sometimes after the father, sometimes it's a mix of both or it will show up with something from a grandparent... it's futile to try and make sense of it. 

[Damon_Tor]

6 hours ago, LynnS said:

I'm also not sure that Lysa's account of Jon Arryn's drug induced fever vision is about physical appearance at all when he says "tell them the seed is strong, tell Robert his seed is strong."  This can be read as singular, specific to one particular offspring rather than all of his offspring.

Or he may have finally figured out that his blonde hair and his wife's red hair couldn't possibly produce his son's brown hair.

[Angel Eyes]

29 minutes ago, Damon_Tor said:

Or he may have finally figured out that his blonde hair and his wife's red hair couldn't possibly produce his son's brown hair.

On Jon Arryn's troubles: it's either Jon's seed is weak, or that Hoster forcing Lysa to drink moon tea permanently damaged her ability to produce viable offspring.

I heard this from another thread that Jon was doing research on that. Plus Robert could have inherited his brown hair from his Tully grandfather. 

[Lady Dacey]

31 minutes ago, Damon_Tor said:

Or he may have finally figured out that his blonde hair and his wife's red hair couldn't possibly produce his son's brown hair.

Auburn isn't really red hair, and a person with this hair colour may produce brown-haired offspring. Hair has more than one type of pigment and at least two genes determine its colour. So someone with auburn hair has genes for brown pigment plus genes for red pigment, while someone with truly red hair will have red pigment and very little brown pigment. Because they are different genes in different loci the offspring may inherit the brown pigment producing genes but not the red pigment producing genes, therefore manifesting brown hair phenotype. If the other parent has light colored hair it shouldn't get in the way of the brown pigment manifesting. 

A simple explanation from Wikipedia:

"Two types of pigment give hair its color: eumelanin and pheomelanin. Pheomelanin colors hair orange and red. All humans have some pheomelanin in their hair. Eumelanin, which has two subtypes of black or brown, determines the darkness of the hair color. A low concentration of brown eumelanin results in blond hair, whereas a higher concentration of brown eumelanin results in brown hair. High amounts of black eumelanin result in black hair, while low concentrations result in white hair.

The genetics of hair colors are not yet firmly established. According to one theory, at least two gene pairs control human hair color.

One phenotype (brown/blonde) has a dominant brown allele and a recessiveblond allele. A person with a brown allele will have brown hair; a person with no brown alleles will be blond. This explains why two brown-haired parents can produce a blond-haired child. However, this can only be possible if both parent are heterozygous in hair color- meaning that both of them have one dominant brown hair allele and one recessive allele for blond hair, but as dominant traits mask recessive ones the parents both have brown hair. The possibility of which trait may appear in an offspring can be determined with a Punnett square.

The other gene pair is a non-red/red pair, where the non-red allele (which suppresses production of pheomelanin) is dominant and the allele for red hair is recessive. A person with two copies of the red-haired allele will have red hair.

The two-gene model does not account for all possible shades of brown, blond, or red (for example, platinum blond versus dark blond/light brown), nor does it explain why hair color sometimes darkens as a person ages. Several gene pairs control the light versus dark hair color in a cumulative effect. A person's genotype for a multifactorial trait can interact with the environment to produce varying phenotypes."

 

as I said, it's very complex.