Thursday, May 3, 2012
Science On Spontaneous Abortions
Posted by Charles Mudede on Thu, May 3, 2012 at 10:05 AM
In a post that challenges the facts in a recent WaPo piece about Fukushima, "Phasing out nuclear":
To the existing human suffering in Japan will be added, over time, countless people who will sicken and die prematurely as a result of their exposure to the Fukushima radiation. In addition to cancer, likely negative health effects can include birth defects, spontaneous abortions, brain tumors, diabetes, heart disease, and genetic and teratogenic mutations.About 25 percent of all pregnancies are naturally ended—and that figure could easily be higher, as early terminations are harder to detect and record than late ones. Also, we should not call these terminations "miscarriages"; they are abortions because they almost never happen without a reason. Recall the Bhopal disaster of 1984. According to Independent Media Center in India, "24% of pregnant women exposed to isocyanide Bhopal explosion had spontaneous abortions." These abortions were directly linked to a chemical that polluted the air. Human bodies responded to the chemical in an obvious and recordable way. But our bodies are constantly responding to changes in the environment, and these changes (known and unknown new chemicals, new toxins, and so on) are happening all the time and shaping the human population in ways that are often difficult to understand or foresee.
Some biologists, like Steve Jones (who I admire), argue that human evolution has stopped. The reason for thinking this is a perceived weakening of selection's machine: death. Infant mortality is down, many terrible diseases are curable, it's easy to reach reproductive age—what has death got to work with in societies that have made these significant advances? But selection not only works on what we can see and record but what is invisible and difficult to monitor. Naturally terminated pregnancies present selection with an excellent material do its cold and blind work.
In the way the body aborts a pregnancy because of challenges in the natural or polluted environment, a human aborts a pregnancy because of challenges in the cultural environment. In fact, choice is precisely what makes humans exceptional. All other primates don't have a choice in the matter. Abortion or neonaticide (before abortions became safe for humans, the thing to do was to kill a baby right after birth—our age of science and technology made the latter far less dangerous than the former) is not an option for a chimp or gorilla. Writes the great sociobiologist Sarah Hrdy:
Scrutinizing newborn group members is a primate universal. But consciously deciding whether or not to keep a baby is uniquely human.
Those who attack abortion clinics and the right to choose, are denouncing something that is essentially human. They want us to be more like chimps and gorillas—animals with souls that no church has ever saved.
36
@26: You are still off-topic. Charles is discussing medical abortions, not ones triggered by blind natural processes. As interesting as it is, it is not germane to the post.
@35: Finally someone clued me in! Thankf Fnarf. Still studying for my Slog forum history exam.
@35: Finally someone clued me in! Thankf Fnarf. Still studying for my Slog forum history exam.
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@25, his name is John Bailo, but he deleted his account here by that name after making one too many obtuse and offensive comments even by his own debased standards. Basically, even he finds it embarrassing to associate with himself.
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@33 -- That does indeed sound beautiful. I am heartened to hear someone has seen such a thing happen.
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@32, I see your point.
And you're absolutely right about death being an easy thing for people to glom onto and lose sight of the bigger picture, if they ever saw the bigger picture to begin with.
I agree wholeheartedly with you on the "survival of the fittest" issue, as well. I've actually seen a person be swayed from a non-belief in evolution to a belief when the actual meaning of "survival of the fittest" was properly explained to him. It was during a dinner and discussion - the discussion provided by a theoretical physicist who is also a devout christian - who explained how he reconciled his faith with his knowledge of the world, the universe and its workings. A pastor asked him to explain then how he reconciled being a christian and believing we're made in the image and likeness of God with "survival of the fittest" and its inherent brutality. The conversation was a beautiful thing to see, as was the light in the eyes of the pastor as he finally grasped evolution.
And you're absolutely right about death being an easy thing for people to glom onto and lose sight of the bigger picture, if they ever saw the bigger picture to begin with.
I agree wholeheartedly with you on the "survival of the fittest" issue, as well. I've actually seen a person be swayed from a non-belief in evolution to a belief when the actual meaning of "survival of the fittest" was properly explained to him. It was during a dinner and discussion - the discussion provided by a theoretical physicist who is also a devout christian - who explained how he reconciled his faith with his knowledge of the world, the universe and its workings. A pastor asked him to explain then how he reconciled being a christian and believing we're made in the image and likeness of God with "survival of the fittest" and its inherent brutality. The conversation was a beautiful thing to see, as was the light in the eyes of the pastor as he finally grasped evolution.
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@31 -- Yup.
And my point is that while death before breeding age is infallible, it is by no means the most powerful actor.
Imagining death gets people a lot more emotionally excited than imagining the difference between repeated generations having 2.0 or 2.05 children per female. Non-experts tend to get so focused on the former that they typically ignore the later, thus missing a huge part of the picture. To my mind, it's worth regularly turning people away from the death example in hopes of greater understanding of the topic as a whole.
Similarly, popular use of the term "survival of the fittest" has misled public discussion of evolution by encouraging people to think first of violent struggles between individuals, when cooperation at many different group size levels can be a huge component of fitness.
I'm convinced that a sizable proportion of those who "don't believe in evolution" don't believe, in part, because they think that means swearing allegiance to beating the tar out of each other on a regular basis. Talking about the wider range of subtler but powerful forces in play might help. (And yes, I know people are gonna continually beat the tar out of each other, but that's quite different than dedicating yourself to it.)
And my point is that while death before breeding age is infallible, it is by no means the most powerful actor.
Imagining death gets people a lot more emotionally excited than imagining the difference between repeated generations having 2.0 or 2.05 children per female. Non-experts tend to get so focused on the former that they typically ignore the later, thus missing a huge part of the picture. To my mind, it's worth regularly turning people away from the death example in hopes of greater understanding of the topic as a whole.
Similarly, popular use of the term "survival of the fittest" has misled public discussion of evolution by encouraging people to think first of violent struggles between individuals, when cooperation at many different group size levels can be a huge component of fitness.
I'm convinced that a sizable proportion of those who "don't believe in evolution" don't believe, in part, because they think that means swearing allegiance to beating the tar out of each other on a regular basis. Talking about the wider range of subtler but powerful forces in play might help. (And yes, I know people are gonna continually beat the tar out of each other, but that's quite different than dedicating yourself to it.)
31
@30, I agree. I think we're quibbling over semantics, essentially.
And I know about sickle cell and why it's advantegous to be a carrier in areas where malaria is common. My point about sickle cell is that if you up the percentage of people who are carriers you then up the risk of two carriers breeding and therefore up the risk of having a greater number of people with full blown sickle cell. Death due to sickle cell helped to keep the number of carriers down. I'm not suggesting it's a bad thing to keep sickle cell sufferers alive, or that sickle cell should be eliminated from the gene pool. I'm also not suggesting that keeping sickle cell sufferers alive makes much of a dent in the overall makeup of the genetic population. I was simply making the point that death is infallible in its ability to produce unequal breeding outcomes. I used sickle cell as an example because it's hard to survive into adulthood untreated as opposed to, say, breast cancer which tends to strike later in life and may not have an effect on an individual's breeding success.
And I know about sickle cell and why it's advantegous to be a carrier in areas where malaria is common. My point about sickle cell is that if you up the percentage of people who are carriers you then up the risk of two carriers breeding and therefore up the risk of having a greater number of people with full blown sickle cell. Death due to sickle cell helped to keep the number of carriers down. I'm not suggesting it's a bad thing to keep sickle cell sufferers alive, or that sickle cell should be eliminated from the gene pool. I'm also not suggesting that keeping sickle cell sufferers alive makes much of a dent in the overall makeup of the genetic population. I was simply making the point that death is infallible in its ability to produce unequal breeding outcomes. I used sickle cell as an example because it's hard to survive into adulthood untreated as opposed to, say, breast cancer which tends to strike later in life and may not have an effect on an individual's breeding success.
30
@27 -- the point is that over continued generations, a gene which results in a few percent more or fewer children has an incredible effect on the distribution of that gene (and those near it in the chromosome) in the population. Given the size of the human population, the social structures/interventions we have that folks decry as "disrupting selection" aren't terribly powerful. They would have to be held in place for much longer than any civilization (and thus its technology) has yet survived in order to keep the gene frequencies from reverting to what some would romanticize as the "natural" state of things.
When most people talk about "evolution", they're talking about their fantasies of what is "natural" and "good" and not about the actual math and science of what happens.
Sickle cell is a poor example. It is now believed that being heterozygous (one sickle cell gene copy, one normal) protects against malaria. Thus there is "selection pressure" to keep copies of the gene present in populations where there is malaria -- heterozygous individuals have greater breeding success (due to not dying of malaria) than those with two "good" copies. Treating the sick (two sickle cell gene copies) does indeed increase the number of sickle cell trait genes around, but the effect is transient -- if the cures are abandoned, the frequencies will slowly revert to a proportion that is correlated to the rate of malaria in the area.
Worrying about interventional activities distorting the gene frequencies of "bad" genes is like worrying about spilling salt in a sandstorm.
When most people talk about "evolution", they're talking about their fantasies of what is "natural" and "good" and not about the actual math and science of what happens.
Sickle cell is a poor example. It is now believed that being heterozygous (one sickle cell gene copy, one normal) protects against malaria. Thus there is "selection pressure" to keep copies of the gene present in populations where there is malaria -- heterozygous individuals have greater breeding success (due to not dying of malaria) than those with two "good" copies. Treating the sick (two sickle cell gene copies) does indeed increase the number of sickle cell trait genes around, but the effect is transient -- if the cures are abandoned, the frequencies will slowly revert to a proportion that is correlated to the rate of malaria in the area.
Worrying about interventional activities distorting the gene frequencies of "bad" genes is like worrying about spilling salt in a sandstorm.
29
The Bruce effect, or pregnancy block, refers to the tendency for female rodents to terminate their pregnancies following exposure to the scent of an unfamiliar male. The effect has primarily been studied in laboratory mice (Mus musculus), but is also observed in deer-mice, meadow voles, and collared lemmings.
The Bruce Effect has also been observed in geladas and it has also been proposed, but not confirmed, in non-rodent species such as the lion. In mice, pregnancy can only be terminated prior to embryo implantation, but other species will interrupt even a late-term pregnancy. The Bruce Effect was first noted in 1959 by Hilda M. Bruce.
http://en.wikipedia.org/wiki/Bruce_effec…
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@24, tdonut: thanks for mentioning that. With that in mind, anything - such as higher IQ, in humans - that results in lower rates of child bearing, is arguably selected against. (A factor can change, from becoming a favorable quality for reproductive success, to becoming a negative one, if circumstances change, or if a certain balance is passed.)
Since we have so few generations to observe, it's far too soon to say. I myself am delighted to be an abject failure, from the point of view of my genes.
Since we have so few generations to observe, it's far too soon to say. I myself am delighted to be an abject failure, from the point of view of my genes.
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@24, yes but death is a guarentee of unequal breeding success. If you make it possible for people, who would have otherwise died before reaching an age when they were able to breed, to live then you change the makeup of the genes that are passed on to future generations.
The advances in treatment for sickle cell allow people with full blown sickle cell - I'm not talking about carriers here - to live through childhood and into adulthood. Having made it to adulthood they can now pass on their genes and so pass on sickle cell. This up the percentage of people with sickle cell. When everyone who had fullblown sickle cell died in infancy or early childhood the population rate of sickle cell was kept down by death.
So, yes, unequal breeding success is the ultimate in "selection's machine". However, death is its infallible hand. The mastery of death therefore retards the machine and clogs its mechanisms.
The advances in treatment for sickle cell allow people with full blown sickle cell - I'm not talking about carriers here - to live through childhood and into adulthood. Having made it to adulthood they can now pass on their genes and so pass on sickle cell. This up the percentage of people with sickle cell. When everyone who had fullblown sickle cell died in infancy or early childhood the population rate of sickle cell was kept down by death.
So, yes, unequal breeding success is the ultimate in "selection's machine". However, death is its infallible hand. The mastery of death therefore retards the machine and clogs its mechanisms.
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@25
Some females abort or resorb their own young while they are still in development after a new male takes over; this is known as the Bruce effect.
http://en.wikipedia.org/wiki/Infanticide…
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@23: But that is not an abortion, natural or otherwise!
Also, I do not think the lions are "abusing" the cubs, I believe they fucking eat them. A bit different, since they have no real choice in the matter, but I digress.
And why does everyone here call you Bailo?
Also, I do not think the lions are "abusing" the cubs, I believe they fucking eat them. A bit different, since they have no real choice in the matter, but I digress.
And why does everyone here call you Bailo?
24
Death is not selection's machine; unequal breeding success is. Death before breeding is simply an extreme example.
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#18
In humans, its very common in remarriages for the step children of the previous parent to be abused. The new couple would want to favor its own progeny.
As such the lions are doing the same thing.
In humans, its very common in remarriages for the step children of the previous parent to be abused. The new couple would want to favor its own progeny.
As such the lions are doing the same thing.
22
The real purpose of anti-abortion laws is to ensure that every woman is a murderer. Not all women need to be PUNISHED for murder, at least not right away, but that punishment needs to be available at all times in case it's needed.
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@16 That makes sense. It is not really surprising that exposure to toxic things might fuck with pregnancies.
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@14: Dude, are you serious? You realize that Charles is talking about purposeful abortions with that line, right?
Do you think Lionesses are bending coat hangers and visiting clinics? They are not purposefully aborting fetuses, natural processes are "blindly" doing so.
And why does everyone call you Bailo?
Do you think Lionesses are bending coat hangers and visiting clinics? They are not purposefully aborting fetuses, natural processes are "blindly" doing so.
And why does everyone call you Bailo?
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@13 I agree with @15. i should have been more clear about this. @14, infanticide by males, a favorite topic of hrdy, is not the same thing. @15, free will is real and product of evolution.
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@13, I took a look at the source and this is what it says "In 1984, 24% of pregnant women exposed to isocyanide Bhopal explosion had spontaneous abortions, as against 6% in a comparison group". So the rate was considerably higher for those women.
I think the 25% is a rough guess by medical professionals because most spontaneous abortions happen in the first few weeks of pregnancy and are not noted by women as miscarriages/spontaneous abortions because the women themselves didn't know they were pregnant. Also, the longer a pregnancy lasts the less likely it is to end in a spontaneous abortion. This is largely why women wait until they are out of their first trimester to tell: the risk of spontaneous abortion drops off precipitously after about week 14.
Furthermore since the source Charles quoted is quoting a WHO report those numbers are taken out of context. The very low number of spontaneous abortions in the control group makes me think they may have been looking at late term spontaneous abortions and not overall spontaneous abortions.
I think the 25% is a rough guess by medical professionals because most spontaneous abortions happen in the first few weeks of pregnancy and are not noted by women as miscarriages/spontaneous abortions because the women themselves didn't know they were pregnant. Also, the longer a pregnancy lasts the less likely it is to end in a spontaneous abortion. This is largely why women wait until they are out of their first trimester to tell: the risk of spontaneous abortion drops off precipitously after about week 14.
Furthermore since the source Charles quoted is quoting a WHO report those numbers are taken out of context. The very low number of spontaneous abortions in the control group makes me think they may have been looking at late term spontaneous abortions and not overall spontaneous abortions.
15
Charles,
You mentioned "In fact, choice is precisely what makes humans exceptional." That said and here's a loaded question to you, "Do you believe there is free will?"
I know it's heavy but I just had to ask.
You mentioned "In fact, choice is precisely what makes humans exceptional." That said and here's a loaded question to you, "Do you believe there is free will?"
I know it's heavy but I just had to ask.
14
Abortion is not "uniquely human".
Lion society is made up of a pride of females and cubs and a set of males who have access.
Groups of rogue males can challenge existing males and force them off the pride.
At that point, the females will abort existing fetuses from the prior dominant males.
13
"About 25 percent of all pregnancies are naturally ended"
"According to Independent Media Center in India, "24% of pregnant women exposed to isocyanide Bhopal explosion had spontaneous abortions.""
Would not that imply the chemicals had no real effect since the rate of the exposed group was roughly the same, a bit lower even, than one would naturally expect?
"According to Independent Media Center in India, "24% of pregnant women exposed to isocyanide Bhopal explosion had spontaneous abortions.""
Would not that imply the chemicals had no real effect since the rate of the exposed group was roughly the same, a bit lower even, than one would naturally expect?
12
Hell, HIV may be providing an intense evolutionary pressure, or at least some sort of evolutionary pressure, in Africa right now.
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@10, no she wouldn't. I don't know any women who've miscarried who would. However, the correct medical terminology for a miscarriage is a spontaneous abortion. Women who have miscarried did NOT have abortions; they had spontaneous abortions. There is an important distinction there and it should be noted.
In non-medical conversations it is perfectly acceptable - I would say preferable and kinder - to use "miscarriage".
In non-medical conversations it is perfectly acceptable - I would say preferable and kinder - to use "miscarriage".
10
Everything else I would have said, has been said already except for this: My mom had a miscarriage in between my brother and me; she would not have wanted to say she "had an abortion."
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Speaking of human evolution, should avian influenza, which appears to evolve each and every year, get the combination right humanity will experience an intense evolutionary pressure that our modern, globalized world will only make worse.
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The rate of evolution speeds up and slows down on a time scale of tens of thousands of years. The slowdown of the last few centuries is nothing compared to that. Call me in ten millennia and complain that evolution is broken. Right now we have no way to tell.
Although... the frequency of genocide in the most dogmatic and fanatic cultures, the most religious, suggests that evolution might not favor that particular human trait for much longer.
Although... the frequency of genocide in the most dogmatic and fanatic cultures, the most religious, suggests that evolution might not favor that particular human trait for much longer.
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@6,
We're in agreement.
You wrote what I was trying to say... that people from highly religious, overly large families are often encouraged to continue on and create their own overly large families, and may do so simply because they're told to.
I agree that being in a large family doesn't necessarily lead to becoming more obedient (just as being in a small family doesn't necessarily lead to being more rebellious). It *might* lead to that, but there are so many other variables in play it'd be hard to sort out causality.
So, yeah, no disagreement.
We're in agreement.
You wrote what I was trying to say... that people from highly religious, overly large families are often encouraged to continue on and create their own overly large families, and may do so simply because they're told to.
I agree that being in a large family doesn't necessarily lead to becoming more obedient (just as being in a small family doesn't necessarily lead to being more rebellious). It *might* lead to that, but there are so many other variables in play it'd be hard to sort out causality.
So, yeah, no disagreement.
6
@2, sorry but I'm going to have to disagree. Being part of/choosing to have a large family =/= no time to question authority/obedience/power to authority (i.e., church).
Those large families you're thinking of were part of the obedience mindset before their family was big. In fact the family is probably big BECAUSE of the obedience mindset and allowing the church to dictate their life choices.
That may mean that most large families you see are members of churches and they may follow their church's dictates strictly and blindly. But it's not because they are large. And a family being small doesn't mean that is exempt from the obedience/church mindset.
Those large families you're thinking of were part of the obedience mindset before their family was big. In fact the family is probably big BECAUSE of the obedience mindset and allowing the church to dictate their life choices.
That may mean that most large families you see are members of churches and they may follow their church's dictates strictly and blindly. But it's not because they are large. And a family being small doesn't mean that is exempt from the obedience/church mindset.
5
Some scientists might disagree that deciding whether to keep a baby is uniquely human. New research shows female Gelada monkeys miscarry at much higher rates when a new alpha male takes over (because he's likely to kill any young that he didn't father).
http://www.huffingtonpost.com/2012/02/27…
http://www.huffingtonpost.com/2012/02/27…
4
In The Better Angels of Our Natures, Steve Pinker offers some interesting thoughts about post-natal depression as an adaptation for assessing the newborn's likelihood of survival, given the mother's circumstances; if the likelihood is low, natural selection will favor the gene line that cuts its losses.
Not that that somehow makes infanticide okay; let's not fall into the natural = good fallacy.
I wonder if anything like post-natal depression has been observed in the other Great Apes?
Not that that somehow makes infanticide okay; let's not fall into the natural = good fallacy.
I wonder if anything like post-natal depression has been observed in the other Great Apes?
3
I hope that Steve Jones up there is being a bit sarcastic in his assessment that human evolution has stopped. He can not be a serious biologist of he does not know how evolution works.
While we have certainly retarded the process with our technology, Jones would only be right if all humans in the world had the exact same amount of offspring, and they were raised in the exact same environment. Even if there are no widescale deaths, fewer amounts of offspring equate to less of your genes in the next generation.
Also, as you touch on above, the majority of pregnancies are terminated naturally, natural selection clearly at work. Many are terminated before the woman even knows she was pregnant.
While we have certainly retarded the process with our technology, Jones would only be right if all humans in the world had the exact same amount of offspring, and they were raised in the exact same environment. Even if there are no widescale deaths, fewer amounts of offspring equate to less of your genes in the next generation.
Also, as you touch on above, the majority of pregnancies are terminated naturally, natural selection clearly at work. Many are terminated before the woman even knows she was pregnant.
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People with large families = people with no time to question authority = people who are obedient = more power to those in authority (i.e., church).
The church wants people to have lots of kids so they'll blindly follow them without question.
The people who bomb abortion clinics are just examples of that blind obedience. They don't care or think about whether people are chimps or humans... they simply obey their masters commands.
The church wants people to have lots of kids so they'll blindly follow them without question.
The people who bomb abortion clinics are just examples of that blind obedience. They don't care or think about whether people are chimps or humans... they simply obey their masters commands.
1
The ancient Romans would throw infants in the garbage dump or sewers if they didn't want them. I believe there is evidence that live infants were thrown in pits under medieval convents. And as we sadly see today, infants are still being dumped in the trash.
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