From the journal Nature this week comes a study that shows how
differences in the age of the parents influences the gender of their
firstborn.
The study consisted of a group of 301 british families, in which
the researchers found if men married women at least five years younger
then them, the chance of them having a firstborn son instead of a
firstborn daughter is 2-1. The same is reversed for the older woman,
younger man scenario, with firstborn daughters occurring 2-1.
A bigger sample covering all England and Wales also showed this
trend.
...What I didn't find so fascinating about the article (in a
local newspaper from an AP feed) is that it's drawn up by the author and
others as a biological mystery (no explanations given)
Although I don't have a lot of time to expand on this, doesn't
this research somehow correlate with the following (discussed last year
here):
Mutat Res 1997 Jun 9;377(1):61-62
Mutation load and human longevity.
Authors: Gavrilov LA, Gavrilova NS, Kroutko VN, Evdokushkina GN, Semyonova
VG, Gavrilova AL, Lapshin EV, Evdokushkina NN, Kushnareva YE
http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?uid=9219579&form=6&db=m&Dopt=r
"...daughters born to old fathers (50-59 years) lose about 4.4 years of
their life compared to daughters of young fathers (20-29 years) "
Gavrilov, L.A., N.S.Gavrilova, G.N.Evdokushkina G.N., Y.E.Kushnareva,
V.G.Semyonova, A.L.Gavrilova, E.V.Lapshin, N.N.Evdokushkina (1996)
Determinants of human longevity: parental age at reproduction and
offspring longevity, Longevity Report (ISSN 0964-5659), 10, 54, 7-15.
Gavrilov, L.A., N.S.Gavrilova, G.N.Evdokushkina G.N., Y.E.Kushnareva,
V.G.Semyonova, A.L.Gavrilova, E.V.Lapshin, N.N.Evdokushkina (1996)
The revival of longevity genetics, Longevity Report (ISSN 0964-5659),
10, 55, 3-4.
Maybe it's just me, but I see a correlation, and a reason
(method?) as to why the two are related: the older parent can possibly
pass on age related mutations to their offspring of the opposite sex,
which is why it's (statistically) decided against.
...Rodney
