How Grandmas May Play Favorites

http://www.newsweek.com/id/222472

by DanielBMarkham • 17 years ago

22 5 17 years ago

newsweek.com

freewheel• 17 years ago

Link goes to Newsweek front page. Permalink for article?

DanielBMarkham• 17 years ago

Interesting -- that's not what I have here.

Link http://www.newsweek.com/id/222472

It includes the article id, which, at least on this machine, takes me to the article.

Here's the print link which I should have used anyway: http://www.newsweek.com/id/222472/output/print Maybe that will work better for you

ginkgo• 17 years ago

The sex determining chromosomes are just two among 23 chromosome pairs in the human genome.

All the number-play in the article is completely pointless.

sorbus• 17 years ago

The article addresses that, albeit very shortly: "It may seem arbitrary to focus on X, one of 23 chromosomes, but it has 8 percent (1,529) of all our genes, including some for fertility and intelligence, which affect reproductive success."

Besides, it's one of the easiest things to see, and hence one of the easiest to look at - and, as it's sex-linked, there is a very clear way to see its effects (differentiating between paternal and maternal grandmothers, and their effects on their grandchildren of either sex). All the other ones have exactly a 25% chance to be transmitted to grandchildren, regardless of the path, and are therefor even more useless to look at.

I must agree, though, that it would be nice if the article had included more statistics about grandparents effects on the survival of children, and less explaining their theories and math.

camccann• 17 years ago

Okay, here's the fun bit: Having a nearby grandmother consistently increased or decreased a child's chances of surviving vs. not having a grandmother around, in proportion to the expected number of shared X chromosomes.

From the article: In other words, the effect of a grandmother perfectly tracked the DNA. "The higher the X-relatedness," the scientists write in Proceedings of the Royal Society B, "the more beneficial effect the grandmother has on that child's" survival. That the correlation held across four continents and four centuries suggests a biological, not cultural, explanation.

Putting this in more specific personal terms, if you're male, your mother has a biological instinct to harm the future success of your sons, even if she is not only unaware of it but aghast at the entire idea.

So, anyone still think that genes don't have much effect on behavior?

How Grandmas May Play Favorites

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