I heard that fourth cousins have no more DNA in common with each other than any two

[raccoon]

random people. Anybody know about this?

[waiting for hope]

1. Delete

[Heidi]

2. Answer here:

http://www.thetech.org/genetics/ask.php?id=284

[Warpy]

3. First cousins might be the same

although if there are any genetic diseases within either family, genetic counseling is necessary before they reproduce.

By the time you get to fourth cousins, that's completely true.

Remember, even siblings can't often be sufficient genetic matches for transplant.

[Jackpine Radical]

4. First cousins-25% (1/4)

2nd=12.5% (1/8)
3rd =6.25% (1/16)
4th =3.125% (1/32)

I have no idea of the common ancestry of 2 random people. It would obviously depend on the pool from which you sample--worldwide, so that every human has an equal chance to be included? A small Greenland Inuit village? Probably everyone is at least 4th cousins.

[dnbn]

12. You need to divide by 2. (nt)

[Captain Hilts]

5. Whew!

FDR: I think it still increases the chance of idiot children.
ER: You can say that again!
FDR: I think it still increases the chance of idiot children.
ER: So, at least we have an excuse, the Churchills don't!
FDR: We're only 5th cousins, old girl.
ER: Damn.

[Ian David]

6. If there are dangerous dominant traits in both main branches of the family, then it isn't...

... a matter of the percentage of common DNA in total, but instead what matters is the presence of one, particular dominant gene.

Genetic Counseling is called for, MOST especially if there is a known congenital defect that common in both of your families.

[raccoon]

7. Well, in my own case, it wouldn't matter, because I'm too old to have kids anyway. nt

[LiberalFighter]

8. The common ancestor between 5th cousins would be

their Great great great great grandparents. Or 6 generations previous.

[LiberalFighter]

9. Wellllll probably depends if there were any inner breeding.

[ayeshahaqqiqa]

10. It's not unusual to find fourth or fifth cousins marrying

and they don't even realize they are cousins. My ancestors who haled from New England were that way--it wasn't until I did the genealogy for the family than anyone realized that great great grandpa and great great grandma were cousins.

[MineralMan]

11. There's not all that much risk for even first cousins...

which is why half of the states in this country allow first cousins to marry without restriction. The other half are silly.

[Nihil]

13. I wonder if there is a correlation ...

... between the "half of the states" that allow first cousins to marry
without restriction and their voting preferences ...?

:evilgrin:

(The risk for first cousins that you mention is only true for "clear"
bloodlines that haven't been closely intermingled further up the tree ...
the "first cousin" bit is simply the representation of the current
generation with respect to the direct parents, not the genetic mix
prior to that.)

[GaYellowDawg]

14. Yes, there is.

My grandmother and grandfather were from upper East TN/SW Virginia. There were four families in that area that were so intermarried that my grandparents were the genetic equivalent of first cousins. 4 of 5 siblings in my father's generation have had cancer (he's battling it right now) and two have died from it. I'd say there's one hell of a risk.

[scubadude]

15. Is that an area of heavy coal mining?

If so they may do mountaintop removal there.

Here's a sobering map. Many many people in those areas are getting cancer.



Here's a link to an incredible site. They have a great documentary "Burning the Future:Coal in America". Watch it, it may bring a few tears and change your life forever.

http://www.burningthefuture.org/show.asp?content_id=14089

Scuba

[GaYellowDawg]

16. No, not at all.

Mainly agricultural.

[mikelewis]

17. Don't fuck your cousin...

"Friends don't let friends fuck their cousins." That's the state motto of Kentucky btw.

[scubadude]

18. Why not. Einstein did....

He did, but I wouldn't...

Scuba