Slashdot Mirror
Fathers Pass Along More Mutations As They Age
ananyo writes "In the 1930s, the pioneering geneticist J. B. S. Haldane noticed a peculiar inheritance pattern in families with long histories of haemophilia. The faulty mutation responsible for the blood-clotting disorder tended to arise on the X chromosomes that fathers passed to their daughters, rather than on those that mothers passed down. Haldane subsequently proposed that children inherit more mutations from their fathers than their mothers, although he acknowledged that 'it is difficult to see how this could be proved or disproved for many years to come.' That year has finally arrived: whole-genome sequencing of dozens of Icelandic families has at last provided the evidence that eluded Haldane. Moreover, the study, published in Nature, finds that the age at which a father sires children determines how many mutations those offspring inherit. By starting families in their thirties, forties and beyond, men could be increasing the chances that their children will develop autism, schizophrenia and other diseases often linked to new mutations (abstract)."
It meshes with the theory that women choose older men as partners because they are in a better position to care for offspring, but will try to have affairs with younger, sexier men. A man's sperm is separate from his ability to care for a child I suppose.
Cue hundreds of slashdot commenters with some vein of "She's been cheating on me with the gardener I just KNOW it!"
Well there is research that shows that women are attracted to different men when they're ovulating than they are when they're not. Link here
Yeah, it's old news to me that the age of the father matters but what I know since earlier is that the telomere count increased in male sex cells and that those was inherited by the offspring which in return might get a chance in living longer.
Or you could argue that maybe not because they got worse protection against cancer.
But seriously. It make sense in an evolutionary way now when I think about it:
If the father has managed to live for long there's a chance his genes are better than a father not as old, by increasing the possibly life length of his offspring the offspring got a better chance of spreading those good genes further.
I hope I remember the telomere part correctly. If nothing else the number of mutations was mentioned to and yes, some will be bad and some will be good but without mutation no evolution and hopefully nature will in a long term perspective manage to pick the good stuff out from the bad stuff. It may not be good for the offspring but good for the future of the species.
The old mention of mutations and telomeres if I don't remember all of it incorrectly was most likely posted on Slashdot to. But maybe two years ago or so.
Except: A woman is born with all the eggs she will ever have (they are not produced over the woman's lifetime). On the other hand sperm are produced more on an as-needed basis. So, there is much more opportunity for problems to arise with eggs (presumably why the chance of having a Down's Syndrome child increases with the mother's age).
I read the studies and this really isn't that big a deal. For instance, the chance of autism is increased by 20-30% but there is still only a 2% chance of actually having autism appear. So, effectively there is a 0.6% (at most) additional chance that autism will develop in a child whose father is over 40. Autism is an especially hot topic right now due to the increase in proper diagnosis and therefore the increase in documented cases over recent years. This isn't due to more new babies being born with autism, but that they are better at diagnosing it and not thinking it's something else. The chances are still more-or-less the same.