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Showing posts with label grandparents. Show all posts
Showing posts with label grandparents. Show all posts

11 Aug 2014

Grandmother's special connection with her son's daughter

There's a few articles explaining why a grandmother is specially close to her son's daughter.  The granddaughter has 1 pair of sex chromosomes (so 1/12 of the total) and of that pair, one of those (1/24 of the total) is an exact copy of her grandmother's.  An X chromosome has been passed down intact through the two generations.

It's calculated in total the granddaughter has 26% of her DNA from her paternal grandmother, not much extra, but a little extra closeness built in.  A quick look seems to suggest that the little girls only get 24% of their DNA from their father's father, but I've not verified the numbers.  However they often get his surname, so hopefully that balances it all out a bit.



image from: http://genetics.thetech.org/ask/ask435
Nice animation on unrelated genetic topic about flies: http://www.dnaftb.org/11/animation.html