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Like the topic suggests, this is about first cousins or closer being able to marry / have children.

I'll pause for the 'ew' reaction.

....

Right. I'll lay out facts in this post, and let you guys debate about if it should even be legal.

For those of you that live in America, yes, cousins can marry in the US. And not just the southeast of America. Common misconception, but there are northeast states, western states... you get the idea... that permit it, some with restrictions, some without.

Some of these facts will concern the USA. Sorry, but I simply didn't research other countries. So if you have additional data, feel free to volunteer it.

Fact: US legislation barring cousins being able to marry predates modern genetics as we know it. If I recall my research correctly, there was a series of tales in the 1800's, where tales of cousin marriages produced malformed babies. From there, it spread, until the law itself reacted, and made the union illegal in states.

The truth is, barring specific genetic problems, the likelihood of genetic disorders in a child born of first cousins is in the neighborhood of 4% to 6%.

In non-related couples (beyond third cousins), this ratio is 2% to 3% If the mother happens to be over 40 years old, the the ratio of birth defects is 4% - 6%, the same as those of first cousins.

Fact: The US is the only modern western country to forbid cousin marriage. No European country forbids cousin marriage.

Fact: Second cousins, according to Clinical Genetics Handbook, have little increased risk of birth defects.

Fact: the following states permit first cousins to marry with no restrictions:

*Note: this data might be a bit out of date, I'm slightly too lazy to go looking through law books again, and I lost my correct data, so I'm relying on a slightly dated source.

Alabama
Alaska
California
Colorado
Connecticut
Florida
Georgia
Hawaii
Maryland
Massachusetts
New Jersey
New Mexico
New York
Rhode Island
South Carolina
Tennessee
Vermont
Virginia
Washington D.C.

Legally, in every state, seconds cousins can marry.

Religiously, Leviticus 18 lists all forbidden sexual relationships. I've looked that over (it's part of the anti-homosexuality thing for those that follow the Bible), and nowhere in it does it list cousin marriage as forbidden. Actually, the Christian / Catholic / exc. god commands several cousins to marry.

Fact: Several well known names (Einstein, Darwin, and several others) married their cousins.


Now I ask you to set aside your 'ew, it's wrong' reaction, and discuss this. How ethical is it? Should first cousins be forbidden from marriage? Or just from having children? (Several states not listed, including Illinois, have that in their lawbooks.) Should they be required to have genetic testing / counseling, as is required in Maine before they marry, and have that as the limit?

Beyond that, what about those closer than first cousins?

I guess it is ok if they are in love and all that stuff. I still have the eww factor.

When there's 6 billion people on this planet and it's increasing exponentially, survival is NOT something that's a concern.

Another bullshit reason.

Genetic abnormalities are 'bugs' in DNA, weaknesses in the gene pool. The 'logic' of what the others you mention are trying to say... let's say that X is a carrier of a genetic disorder (most of which are recessive, and therefore do not manifest unless the person either has no dominate gene to override it, or other differences, like it only being on the X chromosome.)

Now most disorders run in families, like the famed example of Queen Victoria (actually, any of her male children would have had the genetic problem, it was an X linked problem). So if she marries her cousin, Y, then it is possible that he too carries the gene. If they choose to have children, and both Y and X carry the same genetic disorder (but do not 'have' it, since their genetics have a dominate gene, which overrides a recessive gene). Their child, basically speaking, has a one in four chance of ending up with a genetic disorder. Now I know that this is a somewhat simplistic view, but here's how the odds are

25%: double dominate traits, no gene that composes the genetic disorder
50%: One dominate, one recessive, carries the disorder, but does not 'have' it, the dominate gene overrides the recessive gene (the disorder).
25%: Has the genetic disorder

However, that is assuming that both have it. Though there is a fifty percent chance that a family member inherits it, there also is a 1/4 chance they do not... and as for those that have the disorder, though it's cruel to say... they aren't likely to breed.

I hope this makes some sense. Now I don't have THAT great a understanding in genetics, since I am a Chem major, not a Bio or the like major, but I know it's more complicated than that. And the 'rumor' isn't actually very justified. I gave a percentage of birth defects. in first cousin marriage.. which also applies to women over forty. Four to six percent, compared to two to three. And with a simple genetics test, would-be parents are warned if they could have problems with their child, so that potentially cuts down the percentage.


Laia Moon: Actually, I was thinking more along the lines of uncle / niece or the like (they're closer than first cousins as well), but you do have a point.

ummm..... ewwwwwwwwww! No I wouldn't even though people disagree I wouldn't. eek

......
Uhm... did you even read the first post? Because if you did, you're basically saying that women over forty are not having children either, because THEY have the same odds of having a birth defect.
I dunno about you, but I think that's a Bad Idea.


This also applies. If I remember one college lecture correctly, the Earth technically is overpopulated by humans. So there's too many people already.

For me it's ok if the (grand)father/mother are not from a single couple-person, because if yes, child(ren) of these cousins would have genetic problems...