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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)."
I just need to jerk off and store my sperm in the freezer at the age of 20? But then isn't mutation the key to natural evolution?
Love many, trust a few, do harm to none.
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
... They'll pass on super-powers!
But seriously, who thought that leaving something like fathering a child would lead to fewer or the same number of mutations? Everybody who's everybody knows age and telomere shortening leads to a higher rate of mutation... That's why if we didn't otherwise get killed, wear out or otherwise malfunction, we'd eventually die from all the cancer.
The testes are towards the outside of the body and vulnerable to all sorts of things, while the ovaries are better protected. Furthermore, sperm is produced over the course of a lifetime, whereas eggs aren't. The end result is that eggs are likely to have the original genetic material of Mom, while the sperm is more likely to have been modified (by radiation, damage from trauma, copying errors, etc) from the original genetic material of Dad.
This seems like a good evolutionary strategy, however it arose: Mom provides a version that has allowed her to survive and reproduce, suggesting a minimum viability, which she passes on to the child. Dad provides a version of an evolutionarily successful human that is modified, allowing the species to improve itself (And if he's lived to old age, he was probably an effective survivor evolutionarily speaking).
I am officially gone from
men could be more mature (no need to get in a divorce situation due to a driving urge to mount some other female) and be earning more money, thereby ensuring a more stable and financially sound basis for their household.
that the chance the kid might come out with biological issues is a slight increase. while a younger father has a significantly increased chance to still feel a need to sow the wild oats and not be earning a lot
not that older men can't be broke, and not that older men can't still cheat. but it helps to have all your sexual adventures when you are in your 20s, and not feel the need to do that when you are older. additionally, marrying older means the woman is more mature too, and you are more mature, and so the chance of your marriage lasting is greater because you understand the value of commitment over impulses, you are more interested in settling down, and you can pick the right spouse based on more ephemeral mature qualities rather than the mistakes you can easily make in your 20s and then feel like leaving the person later. all of this is of course better for kids: a stable home of mature parents who earn more money
in other words, this news is a big shrug: "so what." the beneficial factors for having kids in your thirties and forties vastly outweigh the slight genetic risks
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
I was 40 when my son was born, and I can't keep up with the little mutant (though I hear of a special school for kids like him out in Westchester County, NY). There's a reason people have kids in their 20's, it's a physically exhausting challenge.
But yeah, the mature relationship with my wife and stable financial situation are nice. Though I do wish I could stay awake past 8:30 PM.
So older men may father more sick children. But they also father longer-lived ones.
Not to mentation not all mutations are bad. Walking upright was a mutation at one point and I'm pretty glad we got that one :P
I'm hard at work polluting the gene pool with my dangerous mutant offspring. Bwa ha ha ha!
Scruting the inscrutable for over 50 years.
I said "So, since I was about 40 when our daughter was born, are you going to start blaming me for her 'behavioral issues"? Her response was, "What do you mean 'Start', I already DO!"
Sigs are for losers
I was 35 when I conceived my son. He was diagnosed with a 'de novo' (new) mutation in one of the two copies of his MLL2 gene: a single base pair was deleted at position 2272 ("c.2272delG"). This causes half of his MLL2 proteins to be not working resulting in Kabuki Syndrome. He has an academic IQ of around 50, but with some tasks he out smarts everyone I know: he can instantly see who are missing from a certain setting. Saw him walk into his class room, look around, walk to his teacher and when asked by her who were missing, mention the names without hesitating (or looking around) for a second.
Although women's sex drive (supposedly) increase through late 30's, fertility does not. All that worry in your 20's about your girlfriend getting pregnant turn into worries in your 30's that your wife won't get pregnant.
:wq
I never understood the desire to voluntarily be a genetic and memetic dead end. The emotional and psychological benefits outweigh the costs.
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
You're mischaracterizing it. As I understand it:
- Until recently it was assumed that, in mammals at least, females were born with all the egg cells they would ever have, rather than having new ones developed from stem cells over time.
- But this was apparently based on the observation that the number of immature egg cells present diminished with time from initial numbers were adequate (by a couple orders of magnitude) for the "born with 'em all" explanation to work, not by some hypothetical experiment marking some girl's egg cells and then examining her ovaries later in life to see if there were unmarked cells.
- Recently it was noticed that the explanation didn't hang together well for mice.
- Further experiments on mice showed that they had special stem cells in their ovaries (apparently the same kind as produce sperm in males) and that these cells did form new egg cells (or at least immature egg cell precursors) during the mouse's adult life.
- This new reported experiment shows that human ovaries have the same sort of stem cell, and that transplanting human ovary tissue with labeled pre-egg stem cells into a suitable mouse ovary (where they can be observed and receive both human and mouse signals) causes them to produce new immature human egg cells (in human ovary tissue!), just like the mouse stem cells do for the mice.
This strongly suggests that they may do the same in human ovaries. If so, the menopause is something else shutting down ongoing egg production, not necessarily the exhaustion of a fixed-at-birth supply.
It ALSO strongly suggest that, even IF the human immature egg production IS stopped by the time of birth (or some other very young age) and the menopause IS an exhaustion of a fixed supply, providing appropriate chemical signals could (re)activate the egg cell production, delaying or reversing menopause. (It also hints that this could be done without extensive side-effects beyond those you'd expect from ongoing fertility, because it appears to be a normal mechanism in at least some mammals.)
Either way it shows that drug intervention to delay or reverse menopause in humans is a realistic target.
Further, a releated article referenced from this one ("Old Mice Made 'Young'-May Lead to Anti-Aging Treatments.") describes an in-vitro experiment on reactivating senescent stem cells with signals from non-senescent cells, by growing them in a flask separated by a membrane that allows signaling chemicals, but not cells, through. If the same can be done stimulating egg production in human ovary tissue, an extension of the experiment with the signaling chemicals transferred between separate cultures using an intermediate step that sorts out the chemicals (for instance by chromatography) could home in on the responsible chemicals, leading to their identification and the identification of the relevant receptors. That's enough information to enable the design of drugs and therapies to achieve the same effect in adult humans.
The road is now clearly mapped.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Children are stressful, and accordingly parents are consistently less happy than non-parents, despite their assertions to the contrary.
If you're infertile, or if you lost custody in the divorce, and this is your rationalization to help you stay sane, then stop reading at this paragraph. You're absolutely right. Children are nothing but stress and heartache, and you should pity us as you jet off to your vacation in Europe, made affordable by the fact that you never had to buy any diapers. Children are nothing but heartache.
If you've chosen never to have children because you don't want the responsibility, then stop reading at this paragraph. You're absolutely right. You don't want the responsibility. There's no shortage of people on a planet with 7 billion of us. You should pity us as you jet off to Bali...
Still here? OK, here's what this parent knows. Children are stress. Children are heartache. My children are the gray in my hair, and the points on my blood pressure.
And they and their mother are every bit of the joy in my life. Have you noticed when storytellers want to paint a picture of a man in psychotic amounts of pain and regret, they take away his family and he Goes Mad From the Grief? If I lost my wife and children, there would be nothing left but to crawl into a bottle, screenprint a skull on my chest and run off to kill the Emporer in the arena.
I worked with a man this week who makes millions a year. He's pushing fifty, and he still lives like he's twenty. He's a gym rat, could probably trade his car for my house, dresses hip and expensive, and has enough real estate to host the President of the United States without shame.
For all that, this man seems manically adrift. Since this is Slashdot, I'll pull a geeky Jim Butcher reference and tell you I don't think this guy's house has a threshhold. He catered in expensive food from a local "in" restaurant, and he seemed to think commercial cooking was the best you could get. He took a call from his much younger grilfriend, and he seemed ... less ... not more, like a lot of happily married guys I know when their wives walk in the room, as if the two of them together were more than the sum of the two of them apart. Every ounce of his expensively toned and coiffed appearance screamed "I'm desperately hanging on to my youth." To be fair, I look like a guy who can't get to the gym nearly enough, has pulled out far too much of his own hair, has luggage under his eyes and has a face with worrylines that look like a highway map.
I felt kind of bad for the guy, like watching a child with a lot of toys, but no friends, versus a kid with a lot of friends, but nothing more than sticks and a vacant lot to play in.
Children are more than just responsibility and care and exasperation. They're joy and hope and -- what's the cliche -- "the embodiment of God's belief that the World should be given another chance."
There is more to the baby than the sound of the cries and the smell of the diaper. Don't worry about me and my happiness. Sure, I'm hemorraghing money, losing sleep, losing my voice from the shouting, pushing the clinical definition of obese, shedding hair like a cat in the spring and probably losing my sanity in the process... ...and I would cheerfully murder any genie that tried to take me back to my early 20s. :-)
I traded my "happiness" for joy.
He put his boots up on the table and made a face. "The sig," he smirked. "You can waste your life in search of the sig."