Epigenetics is a very interesting area, and I expect it to increase in importance following the ENCODE project that just came out.
The NYTimes article is a bit strange, though, trying to politicize epigenetics through the "mommy wars". The article also muddles the difference between genetic issues due to aging fathers and epigenetic issues. The recent Icelandic study links mutations in sperm from aging fathers to autism and schizophrenia, which is genetic (the mutations show up in genome sequencing), so it's basically irrelevant to the article's epigenetic thesis. The NYTimes article mentions a theory that maybe epigenetic regulation is reducing DNA repair and causing mutations, but that's a pretty tenuous connection.
It's silly to turn this into a "blame game", but it is interesting that males and females contribute different types of genetic errors: females typically introduce chromosome errors, while males introduce DNA mutations. 20% of human eggs have the wrong number of chromosomes, compared with 3-4% of sperm. A cell has to split the chromosomes twice in meiosis to form a gamete, which is a difficult process where a lot can go wrong. Eggs sit around potentially for decades and then need to twice split properly, and this becomes much more error-prone with age. The first split happens at ovulation, and the second at fertilization (which is much later than I'd expect). These errors in chromosome separation are the leading cause of miscarriage and mental retardation. On the other hand, males are the main source of DNA mutations, since sperm are constantly being created, and each round of DNA replication has a chance to introduce errors. [Reference: Molecular Biology of the Cell, chapter 21, which is an interesting book]
eggs don't sit around for decades. a study published recently discounted the theory that a female is born with her entire complement of eggs - to the contrary, like sperm, eggs are produced throughout the female's life.
"In the past decade or so, the study of epigenetics has become so popular it’s practically a fad."
Well, that's the one statement in the article I can readily accept as true for purposes of discussion here. Much more debatable is the assertion further down, "Twentieth-century Darwinian genetics dismissed Lamarckism as laughable, but because of epigenetics, Lamarckism is staging a comeback," which includes a link to a low-quality source. Much better sources on epigenetics for our discussion here are
"Epigenetics again: will it cause a revolution in evolution?"
The scientifically careful study of gene regulation is NOT going to revive Lamarckian ideas, not at all. But speculation about this is probably in the popular literature again for years to come.
According to Warren Farrell NYTimes is systematic and deliberate in perpetuating misandry. This is coming from a man who was both a founding member in a major feminist organization(N.O.W) and a writer for the NYTimes.
The New York Times isn't the only media organization guilty of this. It is systemic in a lot of Western media outlets, small as well as large. Interesting to hear it pointed out by someone who cannot credibly be acused of being ignorant of gender questions, though.
Something to keep in mind when the blogosphere lights up about how STEM is a "boy's club". It's not that there isn't merit to gender issues in STEM. It's that the dialogue is manufactured by people whose goals aren't egalitarian. If you don't educate yourself in the nuances of gender issues and postmodern powerplays you're going to be the sucker blown full of hot air.
I agree with you to an extent; fathers are often seen as incapable of raising children in American culture. However, do you know if there is any literature or articles/discussion on this? (In particular about how fathers are seen, and more broadly on the misandry.)
There is no such thing as institutional misandry, so no, misandry does not permeate our culture. However, the headline is total click bait, but this is the NYT so no surprise there.
I clicked the link expecting to find a discussion on the role a father has in the raising of children.
What I found was a wandering discussion about epigenetics with zero real-world applicability, given that all Fathers-to-be or existing Fathers cannot rewind the clock.
Changes in a childs crucial upbringing years will have orders-of-magniture more effect than this stuff.
Besides, it's dangerous to program little ears with 'you can't help being fat, it's because your father ate too much as a teenager'.
Personal responsibility is the most important thing for a child to learn. With personal responsibility, even the fattest person can get back to a normal weight range.
Father's primary impact is in his genetic material. Secondary impact is his parenting impact which starts to matter mostly after child is 2 years old. Before that, from conception to birth to 2 years, mother is much more important.
My daughter is two weeks old today. In the past 14 days, my wife has been responsible for providing 100% of what our baby consumes, but at least half the time, I'm the one feeding her (we're about 50/50 breastfed/pumped breastmilk in a bottle).
Aside from that, there's effectively no difference in our roles in caring for her. We both change diapers, we both bathe her, we both hold her and comfort her when she's fussy. We don't pay any particular attention to making it a 50/50 split for these activities, but it probably works out to approximately that, for all intents and purposes.
Right now her schedule seems fairly nocturnal (she seems most awake from ~2300 to ~0400), and I tend to be the one up with her during that time, since I find I'm pretty productive during those hours anyway (I've gotten pretty good at one-handed typing).
On a practical level, there's effectively no difference in the amount of care provided between her mother and I. Your statement that her impact is "much more important" is fairly offensive to me (and while I haven't bothered talking to my wife about a comment on Hacker News... I suspect she would be equally offended).
Congratulations! My daughter was born almost four weeks ago, though we've only had her home a week (she was premature and spent a while in the NICU.) I'm glad you're getting stuff done at night; I've been stuck on the same moderately complex C++ state machine implementation since she was born. I'm just too tired to load the problem into my head.
While my wife is theoretically capable of doing everything on her own we share duties like you do, if only because there's no way I could allow the woman I married to suffer the entire burden of childcare unsupported. I don't know of anyone who does things any differently.
> I've gotten pretty good at one-handed typing
In another context that would be a source of shame, not pride :)
In bearmf's defence, we do matter more to the child after 2 years old. What we're doing now is supporting the mother.
JshWright, congratulations! I am sure you are going to be a great father.
That said, you cannot be a mother to your child. Your roles now are approximately equal, but they will inevitably change over time. Feeding and changing diapers is enough for now, and that indeed can be split between partners, because baby cannot really tell the difference right now.
For further normal development, babies need to develop a bond with their mother. This gives them a fundamental sense of security. It is one of human baby's primary needs which is also observed in most mammals.
Children later become attached to their fathers. It is a different experience for them, which involves more "rational" thought instead of primary urge to bond with their mothers.
I'd be interested in seeing any research you may have seen that supports your position. Anecdotally, that hasn't been my experience (in those around me, obviously)
However, I see that there is nothing in the article specifically about primary caregiver being female. To summarize, it is better to have one primary caregiver who has established a strong attachment with child. Traditionally it has been a female role, and I do believe women are better suited for it.
I don't see anything in that article to suggest 1 primary caregiver is best. The sense I got was that children got a benefit from having a strong attachment, but no arguement or experiment to test for weather 1 strong attachment is better than 2, possibly weaker, attachments.
Also, I am always suspisous of 2nd hand science reports, especially when they do not provide a direct link to the original paper(s). If anyone does track down some research papers on the subject, please post it here.
Sort of ditto gizmo686; the article cited confounds primary caregiver and mother, and I would be surprised if the authors of the source articles had the kind of data that would disambiguate the two. Which women are better than which other caregivers? The idea that every women/mother is automatically better suited as primary caregiver is a old stereotype that continues to do harm.
> For further normal development, babies need to develop a bond with their mother. This gives them a fundamental sense of security. It is one of human baby's primary needs which is also observed in most mammals.
All due respect, but you're talking garbage. Please stop with this sexist drivel.
Yes, I do have a daughter.
I have never said that babies do not recognize their fathers. It is just that their attachment to mother is usually more important in their first few years of life.
A baby can bond with the Father emotionally just as much as the mother. I know a few babies that nurse from the mother, but for comfort will always go to their father.
Babies are quite smart and are fully capable of bonding with multiple people, and can even assign roles to them: This person for this need, etc.
"Experts have known for some time that lifespan is linked to the length of structures known as telomeres that sit at the end of the chromosomes that house our genetic code, DNA. Generally, a shorter telomere length means a shorter life expectancy. ... However, scientists have discovered that in sperm, telomeres lengthen with age."
Causal links cannot be drawn with that paper. This study was unique in showing that telomere length determination by paternal age was generationally additive. It was not designed to determine if older paternal age translates into longer lifespan.
This article is clearly on the nature side of the "Nurture versus Nature" argument and clearly genetics can play a big part in how your child turns out. But why can't we just say "both" to the nature versus nurture argument? Who hasn't been either negatively or positively impacted by the role of their fathers once born?
To me it seemed like the article was less about nature vs nurture and more about the author's resentment that men aren't held as accountable for their children's health as mothers are:
From the article,
Older mothers no longer need to shoulder all the blame: “It’s the aging man who damages the offspring."... The well-being of the children used to be the sole responsibility of their mothers. Now fathers have to be held accountable, too. Having twice endured the self-scrutiny and second-guessing that goes along with being pregnant, I wish them luck.
The author really seems to buy into the concept of a blame culture doesn't she. People don't seem to realise that there is a chance of 'bad' stuff happening and if they want the good stuff they need to take a risk. You might be able to minimise some risks but if you obsess over them you're going to go down the path of seeing only danger everywhere.
Of course this blame culture develops and spreads through social networks where people talk behind the back of someone who doesn't have a perfect child and blames their genetics or parenting skills or lifestyle choices.
The blame culture is a terrible problem. If nobody is responsible for anything because it's not their fault, and somebody else is to blame, how are people going to become self-reliant?
I'm assuming your question is genuine rather than rhetorical.
If a person believes that their personal outcomes are largely or totally created by circumstances out of their control, they will have difficulties becoming self-reliant. Blaming other people and other things for personal failings and problems seldom leads to better outcomes.
The difference is that any Lamarckian epigenetic influence would still be passed on at conception, and is at any rate set throughout the father's entire lifetime. There's no actual period of time, like pregnancy, that presents itself as a particular opportunity for criticism.
Both sexes' lives before conception and pregnancy matter - in both cases, cumulative damage to reproductive cells is more likely the older they are. (Women in addition have pregnancy, during which there can be big affects on the embryo, for example if she binge-drinks.)
The point of the article was that we knew little of the non-pregnancy effects before recent years. And while that information applies to both sexes, it is socially more significant for men, who previously were not considered relevant in this matter, but now are.
Higher ages of conceiving babies in both sexes may be contributing to a rise in autism and so forth. But what is novel is that we already knew that was true for women, now the data shows it is true for men as well.
From what is this based on? It is not congruent with literature I have read on the matter. For one, gametes from the aged father are vastly more likely to incorporate denovo (typically deleterious) mutations.
PLoS Medicine: Contrasting Effects of Maternal and Paternal Age on Offspring Intelligence
Evidence is accumulating that advanced paternal age may exhibit a wider range of effects on the health and development of the offspring than increased maternal age (which is largely confined to risk for Down syndrome). Advanced paternal age is a risk factor for childhood conditions such as cleft lip and palate; childhood cancers and congenital heart defects [1]; and neuropsychiatric conditions such as autism [4], schizophrenia [5,6], epilepsy [7], and bipolar disorder [8]. Advanced paternal age also appears to affect mortality, and an intriguing analysis of family history data from European nobility found that older age of fatherhood (greater than 45 years) is associated with a reduction of about two years in the life span of daughters [9].
This is based primarily on the fact that the risk of Down's Syndrome and pregnancy complications is easily observable, whereas the risk of various other things associated to paternal age are harder to see.
For the most part, the bigger the risk, the easier it is to observe.
However, if you have hard numbers (rather than a piece that is mainly speculative), I'd love to see them.
Understand that I did not post that question for reasons of vanity. I really wanted to know what led you to that belief (I have not found much evidence supporting it) and am still interested in knowing, in order that I might update my beliefs if necessary.
I at least cited something. I picked up the article I had read most recently. Speculative or not, it was published in a peer reviewed journal by those active in the area. I urge you to do your own research and come to your own conclusion. As these things are not known one can only give hypotheses on their causes. Statistics which are often not done well in the medical field are not necessarily stronger than reasoning from first principles.
If you have access to any geneticist, autism researchers or biologist do ask them. And consider. De novo mutations are culprit for many rare diseases including those like autism (each particular case often to rare causes) with non-specific causes. In terms of the gametes which both parents provide, sperm cells unlike ova, have a vastly larger number of these errors with probability increasing with time. This is a stronger argument than something is hard to observe and does not assume that the researchers did not think of something fairly quite obvious. The reason for Down Syndrome and maternal age also has a solid biological hypothesis that is almost inverse (not new mutations but chromosomal damage, usually catastrophic -> miscarrying).
I was actually interested in what made you come to hold this belief because it is not in line with much of what I have picked up in the literature. If you can give a solid counter reference, speculative or not I would be interested. A cursory search on my part did not find anything supporting your claim.
First of all, I think my glib one-line response carried a lot more certainty than I should have expressed. My bad.
The main reason I believe maternal age is a bigger issue is because of the absence of evidence about paternal age. It's pretty well established epidemiologically that maternal age is a problem, but there is far less evidence about paternal age. That suggests that whatever problems paternal age causes, they are harder to observe. The most common reason an effect is hard to observe is because it is small.
That's the extent of it. It's more or less the same reason I take the media's latest "new study suggests XXX might cause cancer" stories with a grain of salt.
I haven't looked into this deeply at all. If you have lots of info on it, you should probably not update your beliefs.
I took that undercurrent as slightly more firm than tongue in cheek. The overall description of the science and its implications were interesting enough to make the article worthwhile.
Everyone has a bias, and a popular article is going to let that show through more than a scientific paper, to make it interesting.
You may as well complain that comics are funny when they observe the human condition.
The NYTimes article is a bit strange, though, trying to politicize epigenetics through the "mommy wars". The article also muddles the difference between genetic issues due to aging fathers and epigenetic issues. The recent Icelandic study links mutations in sperm from aging fathers to autism and schizophrenia, which is genetic (the mutations show up in genome sequencing), so it's basically irrelevant to the article's epigenetic thesis. The NYTimes article mentions a theory that maybe epigenetic regulation is reducing DNA repair and causing mutations, but that's a pretty tenuous connection.
It's silly to turn this into a "blame game", but it is interesting that males and females contribute different types of genetic errors: females typically introduce chromosome errors, while males introduce DNA mutations. 20% of human eggs have the wrong number of chromosomes, compared with 3-4% of sperm. A cell has to split the chromosomes twice in meiosis to form a gamete, which is a difficult process where a lot can go wrong. Eggs sit around potentially for decades and then need to twice split properly, and this becomes much more error-prone with age. The first split happens at ovulation, and the second at fertilization (which is much later than I'd expect). These errors in chromosome separation are the leading cause of miscarriage and mental retardation. On the other hand, males are the main source of DNA mutations, since sperm are constantly being created, and each round of DNA replication has a chance to introduce errors. [Reference: Molecular Biology of the Cell, chapter 21, which is an interesting book]
Last week I read the book "The Epigenetics Revolution", which I recommend as it gives a good description of epigenetics. http://www.amazon.com/The-Epigenetics-Revolution-Understandi... (non-affiliate link)