I don’t have any knowledge about children who are the product of incest, but this article is an interesting discussion on the pros and cons of inbreeding.
It’s all about how you phrase it: “The chances of defects increases 2%.” or “The chances of defects doubles.” Most people see the first as no big deal and the second as a major concern despite being the same thing. I.e. people are bad at understanding statistics.
And that’s just the “one off” case. Letting large numbers do it with no controls would get ugly.
I heard on House that the problems only start with the 2nd & 3rd generations–if you and your brother each marry one of your cousins and then your children marry your brother’s children, etc. etc.
The royal families had interbred for generations before hemophilia showed up.
Is that real?!
In the thread about possible revolutionary technologies, I considered (but didn’t post there) the idea that gene therapy might make it possible for siblings to guarantee that they wouldn’t pass on any defective genes to their children. In fact, if you’re going to go the full “Gattaca” route and laboriously engineer people, breeding “within the blood line” might actually be preferable.
Thanks. Odd that, in the map, India would be broken out into northern and southern zones to show differences in intermarriage.
No, they’re not the product of inbreeding. They’re just (severely) ugly normal people.
I would like to point out that inbreeding did not cause the hemophilia that ran rampant through European royalty. Inbreeding does not somehow ‘damage’ the genes; it simply increases the chance of two deleterious mutations being paired together. With regard to hemophilia, the gene was so dangerous because a carrier mother has a 50/50 shot of producing a hemophiliac son. Because Queen Victoria’s numerous progeny intermarried with almost every other royal house, they spread the gene to their descendants. Tsar Nicholas II was not a hemophiliac nor a descendant of Victoria; his wife Alix, however, was a descendant of Victoria and a carrier for the gene.
How do you know that? For all I know, they’re the poster lads of inbreeding, the product of two or three centuries’ worth of concerted and unrelenting inbreeding.
You wouldn’t have some cite for that, would you? I vaguely recall seeing some context for the image a while ago but I’ve forgotten all the details and I can’t google it back up again now.
I’ve heard of studies where mice will not mate with their first cousins in the wild, only 2nd cousins or more (sorry, no cite).
I also was under the impression that inbreeding within the same generation (i.e. brothers and sisters) was not as bad as back-crossing (child with a parent). These back-crosses are more likely to produce the mutant phenotypes.
Rat Children of Gujrat. Poster childs for inbreeding.
On average, a pair of siblings are as closely related as a parent-child pair, but siblings vary randomly in how closely they’re actually related.
The basic problem is that all of us are carrying some random recessive mutations in our genetic code (for example, many people are carrying a gene that codes for Cystic Fibrosis but don’t even know they have it, because Cystic Fibrosis is a recessive disease and only expressed if you inherit a copy of the defective gene from both parents, not just one) . Fortunately, when you mate with someone who isn’t a close relative, the odds are that person doesn’t have much genetic code in common with you and whatever defective recessive gene you have will be compensated for by the healthy gene for that trait the other person can contribute. Sometimes, of course, through random bad luck you do end up finding out your partner has the same disease-causing mutation (which is why unfortunately sometimes even unrelated couples have kids with diseases like Cystic Fibrosis)
With incest, the risk of a relative having the same recessive defect you do is higher than it would be in the general population. If incest occurs over more than one generation, it becomes an increasingly higher risk of having recessive genetic diseases show up that random mating with unrelated people never would have uncovered.
Look at purebred dogs. Most purebred dogs have had a lot of inbreeding in their family tree to make sure the desired traits of the breed were not lost. Purebred dogs aren’t “hideously deformed” but many breeds do suffer from various genetic health problems because of the inbreeding. The same goes for “inbred” people - they won’t be hideously deformed, won’t necessarily be mentally retarded, but they will probably have more health problems in general than the average person.
His son is HOT, though.
Charles II of Spain is an example of generations of inbreeding. Supposedly he had such a severe underbite he couldn’t even chew his food, his tongue was so large he could hardly speak etc.
And Lynn, Anne Neville is correct-hemophillia had nothing to do with inbreeding. At least two of her daughters were carriers (Princess Louise never had any children so isn’t known if she was one or not) so she would have been born with the gene. So it was either spontaneous, or she somehow inherited from her mother.
According to the geneticist Prof. Steve Jones, the hemophilia mutation almost certainly occurred in Victoria’s father’s sperm. There was no sign of the disease in the royal family before Victoria started to have children, and such mutations are commonly associated with elderly fathers (her father, the Duke of Kent, was in his fifties when Victoria was conceived).
The products of incest are more likely to result in twins, triplets, etc.
You know… multiples.
Unfortunately, I can’t find the cite just now (could’ve sworn it was on Snopes), but what I remember is that they’re Australian, their ancestry is as normal as yours or mine, and that they’re locally renowned for their homeliness.
Homeliness? That’s too kind a word for their condition.