If a married couple shared the same great, great, grandmother, how would this affect the gene pool?

Question

I shop at Sainsburys,...they have a better car park

Answer 1

Such a couple would either be full of half-third cousins. If it is just a great-great-grandmother, then half, if it is a great-great-grandmother and a great-great-grandfather, then full.

It depends on the genetic fitness of the the couple in question and the chances for allele to pair up to display a trait. The more distant the relation, the less chance there is for alleles *present in that descent* to match up for a trait.

Inbreeding has drawbacks and advantages. If both individuals have "superior" genes in their near common ancestry, their is a chance that they will have offspring who display those characteristics. The same is true for "bad" genes.

Third cousins, however, are essentially "non-related" and the risk drops off farther back unless both parents have apparent hereditary issues. For all intents and purposes, they share 1/64 (or 1.5625%) of their DNA in common if full third cousins and half of that if half third cousins.

Studies have shown that in families with low frequency of close cousin unions in their ancestry that second cousins have essentially the same risks as a non-related couple. The same is true for third cousins.

Answer 2

Their eldest son would be a r****d who shags a carthorse marries a beautiful broodmare who gives him two handsome kids but,continues shagging the old carthorse.

Answer 3

it wouldnt. that would be your cousin i believe 3 times removed and its ok. only your immediate family affects the gene pool andnot 100% of the time

Answer 4

it doesn't affect the gene pool

when I started doing my family tree research, I found a lot of third cousins getting married to each other and I turned out pretty good :o)

Never shopped at Sainsburys, but I did go to Tesco a lot when I lived in Scotland

Answer 5

people who share the same Great Great Grandparents are 3rd cousins...removed is when they are in different levels of generations (like you and your 1st cousin's kids are on dif levels).  1st cousins share same Grandparents...2nd --Great Grand...so 3rd cousins share Great Great Grandparents...but to get to the nuts and bolts you are in no danger of this hurting you.

Answer 6

It would not affect the gene pool at all. The result of incest or inbreeding will only affect unions between parents and their children, siblings to each other, grandparents to grandchildren, and first cousins. Any relatives beyond that circle (within three generations of family relation) are safe from developing a gene pool disorder.

Answer 7

It wouldn't... technically you are not to worry.. If you were to take the family tree of some countries everyone could be traced to just a few great great grandparents.  Nowadays most everyone is related to everyone someway or another.