Racial relations... really close relations

[Dr Adequate]

I can't remember the name of the knight in question, but in Mallory's Morte D'Arthur, there is a knight who is spotted black and white like a cow, as his father was Moorish and his mother English.

You're going to keep me up all night unless I can remember his name.

Bugger.

"Palomides". Am I right?

 

[Luciana]

Well I think they're calculating the odds the wrong way. If you figure into the calculation (a) the probability of a mixed marriage in that society (b) the chances of non-identical twins being borne to a given mother, then that increases the odds.

But given those conditions, the chances of having one white and one black twin aren't all that much.

I realize that the fact that I know twins like that do not invalidate the assertion that this occurence happens in 1 to 1,000,000 cases. It is just that I know so many siblings of entirely opposite colors that I don't find those twins in the report surprising at all.

Btw, does anyone know if/how eye color can change with time? I have a green-eyed cousin, but everybody says she used to be blue-eyed as a kid. What gives?

 

[aerosolben]

Fertility experts speculate that a sperm containing all-white genes fused with an egg with all-white genes, and a sperm with all-black genes fused with an all-black gene egg to produce the fraternal twins.

I wonder how long they spent in the lab to produce this startlingly brilliant finding.

 

[Q-Source]

Because genes to make a protein (melanin, in this case) tend to be dominant over genes to NOT make a protein? Basically, if you have one gene that says " make this protein" and another that says "don't bother to make this protein," you'll still get that protein made.

You say that black genes are dominants because their melanin production tends to dominane. My question again is this, why the hell those genes' proteins are dominant?????

If evolution favours melanine production over non melanine production, it must be because they allow bodies to adapt better to the environment. But I suppose this does not answer my question either because white skin has been favoured by evolution in extreme cold wheather. And if it mixes with black skin, this one predominates.

 

[Dr Adequate]

I realize that the fact that I know twins like that do not invalidate the assertion that this occurence happens in 1 to 1,000,000 cases. It is just that I know so many siblings of entirely opposite colors that I don't find those twins in the report surprising at all.

The last word of my post should have been "low", not "much" ... or "chances" should have been "odds against" ... one or the other.

 

[Charlie Monoxide]

Cute kids!

Can someone explain to me what exactly "race" is?

Charlie (my great-great-great-great-...-grandma was dark skinned) Monoxide

 

[Q-Source]

When you say "genes from blacks are dominant", I don't know what you're basing that on. There are certainly some genes associated with white people that are recessive, blue eyes for example. But when you state that as a general rule --- why should it be so?

O.k. let me say it better "genes from blacks TEND to be dominant". In other words, on average they dominate white genes. I want to know why it happens this way. I know that the answer lies in natural selection, it might be the case that black skin would be more successful to survive or adapt in either extreme cold or hot weather, while whites wouldn't, or would adapt less successfully.

I am speaking on average, it is pointless to discuss exceptional cases, just like the one that opened this thread.

No. The fact that a gene happens to be dominant doesn't mean that it's better. The allele for having Huntingdon's Chorea is dominant, but HC is amongst the filthiest of genetic diseases.

From the poit of view of the gene, being dominant means best adapted to the environment, it allows it to replicate better.
Evolution, natural selection, is based solely on the gene's survival. Whether or not Huntingdon's disease looks to you or any human as a horrible disease is irrelevant.

I cannot say that I am "fitter" than a lobster. 'Cos in a Darwinian sense, I am not.

I think you don't have a clue about Darwinism or evolution. Personally, I consider human beings as more sophisticated and more fitter survival machines than lobsters.

Belem

 

[3point14]

How many births in a year? million to one odds must crop up fairly often if there are enough births? (nine times out of ten? )

 

[Megalodon]

O.k. let me say it better "genes from blacks TEND to be dominant". In other words, on average they dominate white genes. I want to know why it happens this way. I know that the answer lies in natural selection, it might be the case that black skin would be more successful to survive or adapt in either extreme cold or hot weather, while whites wouldn't, or would adapt less successfully.

Not necessarily. Inuits are not white, yet they're more nordic than swedes. American indians are much less dark than the africans at similar latitudes.

I am speaking on average, it is pointless to discuss exceptional cases, just like the one that opened this thread.

As for your average, you maybe should be introduced to one of the greatest gifts portuguese presented to the world: mulata

From the poit of view of the gene, being dominant means best adapted to the environment, it allows it to replicate better.

From the point of view of the gene, dominance is quite irrelevant

Evolution, natural selection, is based solely on the gene's survival. Whether or not Huntingdon's disease looks to you or any human as a horrible disease is irrelevant.

That is the point you are missing. Sometimes the gene is dominant but still compromising the survival of the organism. Other times, the gene is beneficial, but still recessive. And then you have a variety of flavours in between.

I think you don't have a clue about Darwinism or evolution. Personally, I consider human beings as more sophisticated and more fitter survival machines than lobsters.

So, in your opinion, you would be a perfect bottom-dwelling scavenger .
I would guess that the good Dr knows a tad more on the subject than you do..

 

[Dcdrac]

Why is the protein for melanin a negative thing?

 

[bluess]

You're going to keep me up all night unless I can remember his name.

Bugger.

"Palomides". Am I right?

Damned if I know for sure, but that sounds right.

For the eye color thing - Mr. Blue had toffee brown irises 20 years ago. They are now closer to hazel, and show little green flecks. Perhaps the pigment in the iris fades? I've noticed this in my mother too, she used to have dark brown irises, but at 60+ they are definitely lighter in color.

 

[plindboe]

Hmm. Call me a sceptic, but if I was him, I'd be having a DNA test done and taking a hard look at the milkman. The mother is pretty dark too- both parents have brown eyes and the girl is a blue eyed blonde?.

The mothers of both parents where white, so the "white" genes are part of both parents. The grandfathers were both black so the "black" genes are part of both parents too.

What's this sperm with all black genes, sperm with all white genes business?
What the hell are "all white genes"? How many are there? Do they act as a unit?

The article mentions that skin colour is believed to coded by 7 genes. During the production of gametes in both parents, the genes are mixed up, and since both parents contain "white" genes(The ones originally contributed by the grandmothers) and "black" genes (The ones originally contributed by the grandfathers), there's a small chance that all genes the genes in individual gametes are "same-coloured".

 

[plindboe]

How many births in a year? million to one odds must crop up fairly often if there are enough births?

The chance is calculated for that specific circumstance, where two parents, who both have a 50/50 mix of "black" and "white" genes have children. Since that specific family pattern is rather rare worldwide, such a case is pretty unique.

 

[plindboe]

Btw, doesn't this thread belong to the science forum?

 

[Nancarrow]

Surely I can't be the only person for whom the thread title was a set-up for a great disappointment?

Oh well, I guess there's, ahem, plenty of other sites around for that.

 

[strathmeyer]

You say that black genes are dominants because their melanin production tends to dominane. My question again is this, why the hell those genes' proteins are dominant?????

What the hell are you guys talking about? If 'black genes' were dominate, when a white and black person had a child, it would be black.

 

[strathmeyer]

Hmm. Call me a sceptic, but if I was him, I'd be having a DNA test done and taking a hard look at the milkman. The mother is pretty dark too- both parents have brown eyes and the girl is a blue eyed blonde?
What's this sperm with all black genes, sperm with all white genes business?
What the hell are "all white genes"? How many are there? Do they act as a unit?

Half of your genes are from each parent. And your zygote is half of your genes. So, statistically speaking, there's a chance that some of your zygotes are composed entirely of genetic material from one parent.

 

[Luciana]

The chance is calculated for that specific circumstance, where two parents, who both have a 50/50 mix of "black" and "white" genes have children. Since that specific family pattern is rather rare worldwide, such a case is pretty unique.

At least 100 million Brazilians fit this same pattern, black/white. Highly miscigenated societies, like Bolivians, Paraguayans, Peruvians will also have something similar, most likely white/Indian. I would not say it's rare at all.

 

[Silly Green Monkey]

What I learned in Genetics:

Human melanin is coded for by six genes, each with two alleles. One is dominant, the other recessive. Dominant genes command the production of melanin, recessive genes do not. It might be said that the recessive ones are 'damaged' in that they do not produce. All of these genes add up to produce the overall skin tone. Someone who is all dominant, say MMMMMMMMMMMM, would be ebony in skin color. Someone who is all recessive, mmmmmmmmmmmm, would be so pale as to be mistaken for an albino (which is someone who cannot produce melanin at all).

Now, if two parents who are both completely heterozygous, say MmMmMmMmMmMm, it is quite possible, but not especially likely, for them to have children who received all Ms as well as children who received all ms. Each allele can be inherited at the same frequency as the others, so children get a half chance of getting either allele.

It't not that 'black' genes are dominant, it's that dominant genes produce melanin and recessive ones don't. The 'paint' hypothesis of inheritance was proved false long long ago. By the way, completely heterozygous parents are not half-black/half-white by definition. Stupid definitions anyway.

 

[ceo_esq]

I can't remember the name of the knight in question, but in Mallory's Morte D'Arthur, there is a knight who is spotted black and white like a cow, as his father was Moorish and his mother English.

Dr. Adequate got it in one. I don't recall Palomides being described as actually spotted himself, although his shield bore a black/white chessboard pattern (whence, one presumes, the nomenclature of the Palamedes butterfly for example). And I think he was technically of Saracen rather than Moorish stock, although I realize that over time the two terms came to be used increasingly interchangeably.