Poll

Could the use of c-sections, episiotomies and instrumental deliveries lead to an inability for a natural delivery in the future?

No.
6 (24%)
Possibly but it's unlikely.
4 (16%)
Possibly but I doubt it.
3 (12%)
Possibly, I'm not sure of the probability.
7 (28%)
I think it's likely.
0 (0%)
I think it'll definitely happen.
0 (0%)
I don't know but it'd be cool if it did..
1 (4%)
I don't know but it'd be bad if it did.
0 (0%)
I don't understand the question.
3 (12%)
Natural selection is not the cause of evolution, supernatural selection is.
1 (4%)

Total Members Voted: 25

A few selective pressures removed

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midgard

  • 1300
A few selective pressures removed
« on: February 16, 2009, 05:00:17 AM »
It appears that modern technology (or should that be prosperity) has made it possible for some births to occur that wouldn't have otherwise. As such we have changed this part of our species' environment and therefore the selective pressure associated with it. With this, could a future where natural births are virtually impossible occur?

My personal thoughts are this is a possibility but I don't think it's very likely as I don't think this is a very large selective pressure to begin with.

Also, as the perineum can split without an incision I'm not sure whether episiotomies should be included in this - I have included though as maybe one of the possibilities would be a tougher perineum that wouldn't split naturally and as such future childbirths may be impossible without an episiotomy (in Holles Street Maternity Hospital virtually all asian mothers require an episiotomy).

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Mykael

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Re: A few selective pressures removed
« Reply #1 on: February 16, 2009, 05:13:10 AM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.*


*I'm talking about industrialized nations, of course. In Third World countries, natural births would still be necessary.

Re: A few selective pressures removed
« Reply #2 on: February 16, 2009, 03:29:39 PM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.*


*I'm talking about industrialized nations, of course. In Third World countries, natural births would still be necessary.
I don't think a woman wants a C-section. It is surgery and requires time for healing so theres nothing really convenient about it, not to mention the scar. But also sometimes it is easier than a natural birth.
I hate myself for coming here

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theonlydann

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Re: A few selective pressures removed
« Reply #3 on: February 16, 2009, 03:40:21 PM »
I really don't think so... but i wold have to know what percentage of births are delivered this way, and then make up an opinion.

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Mykael

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Re: A few selective pressures removed
« Reply #4 on: February 16, 2009, 05:00:22 PM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.*


*I'm talking about industrialized nations, of course. In Third World countries, natural births would still be necessary.
I don't think a woman wants a C-section. It is surgery and requires time for healing so theres nothing really convenient about it, not to mention the scar. But also sometimes it is easier than a natural birth.
Many businesswomen prefer them because that way they can work the birth into their schedules  :-\

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #5 on: February 16, 2009, 11:18:10 PM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.

But that's sort of the point, if births are hard enough as it is then the change wouldn't have to be that significant to go from possible to virtually impossible. What if even bigger heads and smaller hips were advantageous - with c-sections there would no longer be a selective pressure limiting these to what can still be effective in birth. In other words, have you considered that there could be a non-obvious (e.g. common cause) selective pressure that may actually favour a harder birth (e.g. larger head, tougher perenium, etc.)? By this I mean that a change might occur that has a benefit (perhaps better social skills) as well as something that traditionally would have been a disadvantage (inability to dilate) - something that doesn't seem linked but has a common cause. Wouldn't such a change become more likely the longer time goes on?

I don't think a woman wants a C-section. It is surgery and requires time for healing so theres nothing really convenient about it, not to mention the scar. But also sometimes it is easier than a natural birth.

I'd imagine some do, not just for the reasons given by Mykael but also as some women see it as "easier" to have major abdominal surgery than push a baby out of their vagina. It's amazing how varied women can be, you'd think because they all have a vagina and boobs they'd all want the same things. ;)

I really don't think so... but i wold have to know what percentage of births are delivered this way, and then make up an opinion.

According to a highly reliable source :P the incidence of c-sections are on the increase in the developing world. However, as Mykael point out, that doesn't really mean the number of births where c-sections were essential (e.g. to save baby and/or mum) is on the increase. Plus I don't think any change would occur in the short term as there's no (obvious) benefit to a harder birth.



I am curious if there's anybody who doesn't consider this a possibility but then thinks that humans as a species will become more intelligent...

Re: A few selective pressures removed
« Reply #6 on: February 17, 2009, 06:38:55 AM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.*


*I'm talking about industrialized nations, of course. In Third World countries, natural births would still be necessary.
I don't think a woman wants a C-section. It is surgery and requires time for healing so theres nothing really convenient about it, not to mention the scar. But also sometimes it is easier than a natural birth.
Many businesswomen prefer them because that way they can work the birth into their schedules  :-\
It's called induced labor. And trust me, the Doctor would have an easy time convincing them it would be worse than a natural birth with an epideral.
I hate myself for coming here

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Chris Spaghetti

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  • 12682
Re: A few selective pressures removed
« Reply #7 on: February 17, 2009, 09:44:09 AM »
Evolution favours those who reproduce more often. If women who were unable to have natural births became sexually attractive then given time the genes needed for natural birth would become less and less common and repressed in our genome.

Even once C-Section births became almost universally common there would still be mutants retaining the natural birth for a long time.

Then again, if C-Sections were considered 'normal' and they were given irregardless of whether natural birth was possible then the genes needed for natural birth would still get passed on and would probably spread back out into the gene pool.

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Benocrates

  • 3077
  • Canadian Philosopher
Re: A few selective pressures removed
« Reply #8 on: February 27, 2009, 06:50:00 AM »
Number one, that poll illustrates exactly what polls are stupid. Number two, I tend to agree with the TED speaker who describes the next stage of human as homo evolutis, man who controls the evolution of himself and the rest of the world.
Quote from: President Barack Obama
Pot had helped
Get the fuck over it.

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EnigmaZV

  • 3471
Re: A few selective pressures removed
« Reply #9 on: February 27, 2009, 11:52:37 AM »
I think it might go the other way.  With so many premature births, and the premature babies surviving to reporduce, premature birth may be selected for, making childbirth easier for the mother, as the kid is smaller, and easier to push out.
I don't know what you're implying, but you're probably wrong.

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Moonlit

  • Flat Earth Editor
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  • The Rebound
Re: A few selective pressures removed
« Reply #10 on: February 27, 2009, 11:59:43 AM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.*


*I'm talking about industrialized nations, of course. In Third World countries, natural births would still be necessary.
I don't think a woman wants a C-section. It is surgery and requires time for healing so theres nothing really convenient about it, not to mention the scar. But also sometimes it is easier than a natural birth.
Many businesswomen prefer them because that way they can work the birth into their schedules  :-\
It's called induced labor. And trust me, the Doctor would have an easy time convincing them it would be worse than a natural birth with an epideral.
Actually, Mykeal is right.  I wanted a C-section to begin with because it was easier to deal with.  I didn't have to push or deal with the nastiness that is after-birth.  It was nice, painless, short, and convenient.
You think that a photograph is indisputable evidence?  Would you like me to show you a photograph of Barack Obama having sex with a gorilla?

Re: A few selective pressures removed
« Reply #11 on: February 27, 2009, 02:09:09 PM »
Natural births are hard enough as it is, due to our evolution of both bigger heads and small hips (for intelligence and bipedal motion, respectively). Many women are going with C-section for convenience and plannability, I don't think the change would be that significant.*


*I'm talking about industrialized nations, of course. In Third World countries, natural births would still be necessary.
I don't think a woman wants a C-section. It is surgery and requires time for healing so theres nothing really convenient about it, not to mention the scar. But also sometimes it is easier than a natural birth.
Many businesswomen prefer them because that way they can work the birth into their schedules  :-\
It's called induced labor. And trust me, the Doctor would have an easy time convincing them it would be worse than a natural birth with an epideral.
Actually, Mykeal is right.  I wanted a C-section to begin with because it was easier to deal with.  I didn't have to push or deal with the nastiness that is after-birth.  It was nice, painless, short, and convenient.
I guess I was wrong before. But it has been shown that children born of Cessarian section have more trouble breathing afterwords because during natural birth, all the amniotic fluid is squeezed out of it's lungs. And during
C-Section, that squeezing never occurs. Not that you were wrong or anything, Moonlit. I'm just adding to the thread.
I hate myself for coming here

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Mykael

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  • Professor of the Horrible Sciences
Re: A few selective pressures removed
« Reply #12 on: February 27, 2009, 03:30:39 PM »
My mother was in labour for 14 hours before she finally got the doctor to do a C-section  :o

Sometimes they're very necessary.

Re: A few selective pressures removed
« Reply #13 on: February 27, 2009, 03:51:43 PM »
My mother was in labour for 14 hours before she finally got the doctor to do a C-section  :o

Sometimes they're very necessary.
Of course
I hate myself for coming here

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #14 on: March 02, 2009, 04:06:21 AM »
Sometimes they're very necessary.

Which could very well be the reason we become virtually dependent on c-sections. Especially when you consider that human babies are born one year before they "should" be born (most primates' babies are born with the functions roughly equivalent to a human 1-year-old), maybe babies that stay in longer will survive better. If not then it could be a matter of more intelligent = more likely to survive & bigger head = c-section becomes more and more prevalent until we are virtually dependent on them.

I think it might go the other way.  With so many premature births, and the premature babies surviving to reporduce, premature birth may be selected for, making childbirth easier for the mother, as the kid is smaller, and easier to push out.

I'm fairly certain that preterm births are more likely to die than other babies.

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Pongo

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  • 6753
Re: A few selective pressures removed
« Reply #15 on: March 02, 2009, 12:12:00 PM »
Evolution favours those who reproduce more often.

This, while not far off, this is an incorrect statement.  Hares fuck like bunnies, but evolution does not favor them because they are furry little sluts.  Evolution, or more accurately Natural Selection, favors those most adept to their environment. Like I said though, it's not far off.  If a mutation in insects caused them to become resistant to pesticides, then it would be greatly advantageous for them if they reproduced quickly.  I may just be arguing the way you composed your sentence, but to me it read like you were attributing high fertility to speciation.

Also, I think that arguing this entire point is like wondering if babies are going to start being born without foreskin.  Spoiler: they aren?t.


Quote
If women who were genetically unable to have natural births became sexually dominate, then given time the genes needed for natural birth would become less and less common and repressed in our genome.
fix'd

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #16 on: March 03, 2009, 04:26:57 AM »
Evolution favours those who reproduce more often.

This, while not far off, this is an incorrect statement.  Hares fuck like bunnies, but evolution does not favor them because they are furry little sluts.  Evolution, or more accurately Natural Selection, favors those most adept to their environment. Like I said though, it's not far off.  If a mutation in insects caused them to become resistant to pesticides, then it would be greatly advantageous for them if they reproduced quickly.  I may just be arguing the way you composed your sentence, but to me it read like you were attributing high fertility to speciation.

I think he was using "more often" in a broader sense. In other words a living organism that has one baby reproduces more often than an organism that was killed before it could reproduce.

Also, I think that arguing this entire point is like wondering if babies are going to start being born without foreskin.  Spoiler: they aren't.

If you think the two are similar you really haven't understood the question.

Quote
If women who were genetically unable to have natural births became sexually dominate, then given time the genes needed for natural birth would become less and less common and repressed in our genome.
fix'd

Forget about the women for a moment. What about intelligence, do you think that could provide an advantage?

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EnigmaZV

  • 3471
Re: A few selective pressures removed
« Reply #17 on: March 04, 2009, 11:15:05 AM »
I think it might go the other way.  With so many premature births, and the premature babies surviving to reporduce, premature birth may be selected for, making childbirth easier for the mother, as the kid is smaller, and easier to push out.

I'm fairly certain that preterm births are more likely to die than other babies.

They are, but with advances in medical science, their survival becomes more likely, which means that whatever causes mothers to consistently produce premature babies as some seem predisposed to do, could be passed on to the next generation.  I'm sure we could all agree that the likelihood of a baby born 2 months premature today stands a better chance of living than one born 20 years ago.
I don't know what you're implying, but you're probably wrong.

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #18 on: March 05, 2009, 06:01:02 AM »
They are, but with advances in medical science, their survival becomes more likely, which means that whatever causes mothers to consistently produce premature babies as some seem predisposed to do, could be passed on to the next generation.  I'm sure we could all agree that the likelihood of a baby born 2 months premature today stands a better chance of living than one born 20 years ago.

Preterm babies of today are "competing" with non-preterm babies of today. They are not "competing" with preterm babies of 20 years ago. The fact that preterm babies of today are more likely to survive compared to preterm babies of 20 years ago is completely irrelevant when preterm babies of today are still more likely to die compared to non-preterm babies of today.

Of course, in the end it comes down to reproduction... but it always helps if you can survive until you're old enough to reproduce.

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Pongo

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Re: A few selective pressures removed
« Reply #19 on: March 05, 2009, 10:45:47 AM »

Also, I think that arguing this entire point is like wondering if babies are going to start being born without foreskin.  Spoiler: they aren't.
Quote

If you think the two are similar you really haven't understood the question.

What if having a circumcision made you more sexually attractive and increased your chances of reproducing more?  Does that make the situation more similar, or am I grievously misunderstanding the question?



Quote
Forget about the women for a moment. What about intelligence, do you think that could provide an advantage?

I don't understand what your asking here and I find it very difficult to forget about the women for even a moment.  Are you asking if a higher intelligence would help survival?  Or are you asking if bigger heads will not be conducive to birthing? I don't understand the question.  =(

Re: A few selective pressures removed
« Reply #20 on: March 05, 2009, 10:49:39 AM »
They are, but with advances in medical science, their survival becomes more likely, which means that whatever causes mothers to consistently produce premature babies as some seem predisposed to do, could be passed on to the next generation.  I'm sure we could all agree that the likelihood of a baby born 2 months premature today stands a better chance of living than one born 20 years ago.

Preterm babies of today are "competing" with non-preterm babies of today. They are not "competing" with preterm babies of 20 years ago. The fact that preterm babies of today are more likely to survive compared to preterm babies of 20 years ago is completely irrelevant when preterm babies of today are still more likely to die compared to non-preterm babies of today.

Of course, in the end it comes down to reproduction... but it always helps if you can survive until you're old enough to reproduce.
I could have this mixed up but if I remember right Preterm baby's are more likely to be still born but less likely to have learning disability's.
You can't outrun death forever
But you can sure make the old bastard work for it.

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EnigmaZV

  • 3471
Re: A few selective pressures removed
« Reply #21 on: March 05, 2009, 12:30:22 PM »
They are, but with advances in medical science, their survival becomes more likely, which means that whatever causes mothers to consistently produce premature babies as some seem predisposed to do, could be passed on to the next generation.  I'm sure we could all agree that the likelihood of a baby born 2 months premature today stands a better chance of living than one born 20 years ago.

Preterm babies of today are "competing" with non-preterm babies of today. They are not "competing" with preterm babies of 20 years ago. The fact that preterm babies of today are more likely to survive compared to preterm babies of 20 years ago is completely irrelevant when preterm babies of today are still more likely to die compared to non-preterm babies of today.

Of course, in the end it comes down to reproduction... but it always helps if you can survive until you're old enough to reproduce.

I know, but non-preterm babies of today have more competition from preterm babies today than they did in previous generations, meaning that if a genetic predisposition existed in a woman to produce preterm babies, it would be more likely to be passed on today, because in the past, the babies wouldn't have survived to produce offspring of their own.  It's the same argument as why c-section babies whose heads are too big would become more prominent in the species, just at the other end of the scale.
I don't know what you're implying, but you're probably wrong.

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #22 on: March 06, 2009, 07:03:51 PM »
What if having a circumcision made you more sexually attractive and increased your chances of reproducing more?

It's irrelevant how sexually attractive a circumcised man is, their babies will still have a foreskin.

Does that make the situation more similar, or am I grievously misunderstanding the question?

They're still very much different and I'm guessing you've misunderstood the question (the alternative is you believe a boy fathered by a circumcised man is born without a foreskin ;)).

It'd be more similar if most men weren't born with foreskins naturally and were sexually more attractive and then posing the question as, "Because circumcisions have evened up the sexual attractiveness of men with foreskins and men without foreskins is it possible that all men will eventually be born with foreskins and "require" a circumcision?"

Even if we take your example and make it more in line with the question and ignore circumcisions and say that a genetic mutation causes some babies to be born without foreskins and ask if it's likely it'll become a dominant trait I still do not think it would be similar. Human pregnancies are a very crap compromise between bipedal motion, intelligence/headsize, duration of pregnancy and the ability to give birth vaginally (and probably other things). With c-sections this has created one less thing to have to compromise over - in other words the cost of having to give birth vaginally has been removed.

I don't understand what your asking here and I find it very difficult to forget about the women for even a moment.

 ;D

Are you asking if a higher intelligence would possibly help survival?

Yes.

...are you asking if bigger heads will not be conducive to birthing?

No.

I don't understand the question.  =(

 ::) Get over it.



I know, but non-preterm babies of today have more competition from preterm babies today than they did in previous generations, meaning that if a genetic predisposition existed in a woman to produce preterm babies, it would be more likely to be passed on today, because in the past, the babies wouldn't have survived to produce offspring of their own.  It's the same argument as why c-section babies whose heads are too big would become more prominent in the species, just at the other end of the scale.

I misunderstood what you were saying. When you said, "...premature birth may be selected for, making childbirth easier for the mother, as the kid is smaller, and easier to push out." I thought you meant that the preterm birth in itself would be an advantage that was selected for over non-preterm births. As such I was pointing out that regardless of a preterm birth being easier for the mother, a preterm birth is still a disadvantage when compared to a non preterm birth.

You are right in pointing out that this disadvantage is nowhere near as much as a disadvantage as it has been previously in the past.  Indeed, in this sense I completely agree that if a preterm baby has a selective advantage over a non-preterm baby (perhaps reduced learning disabilities could help them survive and reproduce) then this could flourish now that the survival cost of actually being a preterm is a lot less than before.

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Pongo

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Re: A few selective pressures removed
« Reply #23 on: March 06, 2009, 10:15:41 PM »
Quote
What if having a circumcision made you more sexually attractive and increased your chances of reproducing more?

It's irrelevant how sexually attractive a circumcised man is, their babies will still have a foreskin.

That's exactly the point I was making.  Regardless of how babies are being birthed, it's not going to affect their genes.  If a baby is cut out, it still has the genes necessary to give birth. If a baby is cut up, it still has the genes to grow foreskin.  By theorizing that a circumcised penis is more sexually attractive, it would mean men with circumcisions were reproducing more often.  This relates to the original post because it was stated that c-sections would become the normal method of birthing (just as foreskinless penises would be the normal method of sexing).  Either way, babies will still be born with the genes for foreskin and ability to birth.  It would be many many many years before random mutations lead to either of those gene sets becoming obsolete.  And even then, I'm not sure how easily the genome is willing to shed it's ability to successfully reproduce (figuratively speaking of course, genes have no direction in change).  It's kind of like the male nipple; the female nipple is sooooo important in the survival of a baby that the trait is carried over into men as a useless aesthetic feature.



Quote
Are you asking if a higher intelligence would possibly help survival?

Yes.

I don't think we are in disagreement here.  However, if a species used an excessive amount of its brain, then that is blood that could be used to power muscles.  A species could get wiped out by prey if it's too smart for its own good.  Of course though, humans have clearly made it past this stage.  I am curious why you edited my original question before replying to it?  It changes the tone and grammar of the question.


Quote
It'd be more similar if most men weren't born with foreskins naturally and were sexually more attractive and then posing the question as, "Because circumcisions have evened up the sexual attractiveness of men with foreskins and men without foreskins is it possible that all men will eventually be born with foreskins and "require" a circumcision?"

I don't see how this relates, I don't know of a single baby that has been birthed by caesarean naturally.
« Last Edit: March 06, 2009, 10:21:15 PM by Pongo »

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EnigmaZV

  • 3471
Re: A few selective pressures removed
« Reply #24 on: March 08, 2009, 10:57:59 AM »
The main difference between foreskins and c-sections, are that some women CANNOT give birth naturally because either their babies are too large, or their hips are too small.  For these women, either they'd die, or their baby would die, or both in the process.  C-sections remove this boundary and allow for genes involving baby and hip size to be passed on to the next generation.  Whether a male has a foreskin or not does not really change his ability to reproduce, and even if it did, since it's not something that occurs naturally anyway, it doesn't matter.
I don't know what you're implying, but you're probably wrong.

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theonlydann

  • Official Member
  • 24172
Re: A few selective pressures removed
« Reply #25 on: March 08, 2009, 11:08:19 AM »
The main difference between foreskins and c-sections, are that some women CANNOT give birth naturally because either their babies are too large, or their hips are too small.  For these women, either they'd die, or their baby would die, or both in the process.  C-sections remove this boundary and allow for genes involving baby and hip size to be passed on to the next generation.  Whether a male has a foreskin or not does not really change his ability to reproduce, and even if it did, since it's not something that occurs naturally anyway, it doesn't matter.
Here is an extreme example... Foreskins apparently increase the risk of certain infections and such, i believe. So, while this is kinda extreme, could it be argued that by removing the foreskin, and the chance of infections, you are reducing the risk of those people who have a weakened immune system from dying from those infections, thus passing on weak immune systems with your stupid foreskinlessness?

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #26 on: March 08, 2009, 05:00:18 PM »
That's exactly the point I was making.  Regardless of how babies are being birthed, it's not going to affect their genes.  If a baby is cut out, it still has the genes necessary to give birth. If a baby is cut up, it still has the genes to grow foreskin.  By theorizing that a circumcised penis is more sexually attractive, it would mean men with circumcisions were reproducing more often.  This relates to the original post because it was stated that c-sections would become the normal method of birthing (just as foreskinless penises would be the normal method of sexing).  Either way, babies will still be born with the genes for foreskin and ability to birth.

I understood your point and this is why I said you didn't understand because the point is irrelevant to what was being asked. I'm not suggesting that the way a baby is delivered will affect their genes I'm saying that somebody's genes may affect the delivery.

It would be many many many years before random mutations lead to either of those gene sets becoming obsolete.

I wasn't suggesting that this would happen any time soon, especially considering that c-sections are not readily available to everybody. Even if they were it would take a long, long time for a change considering how massive the potential mating gene pool is for people these days. One point though, human pregnancies are already a massive compromise so any random mutation may not be something entirely new but an enhancement of something around already (e.g. bigger heads to fit bigger brains, narrower hips so female actors don't look silly when they run).

And even then, I'm not sure how easily the genome is willing to shed it's ability to successfully reproduce (figuratively speaking of course, genes have no direction in change).

Exactly, figuratively speaking. How about you stop thinking about some imaginary will of the genome and think about the actual genome and what actually causes direction in evolution. A c-section may not be a natural reproduction method but it is still a successful one, as such if genes that are dependent on c-sections get copied more rapidly and out compete genes that aren't dependent then eventually the c-section dependent genes will become dominant. There will be nothing in those genomes that looks to the future and thinks, "what if c-sections aren't always available?" If we take an example of babies' heads too big for vaginal birth there is no will or forethought of the genome to direct the vaginal birth process to adapt to this new development.

It's kind of like the male nipple; the female nipple is sooooo important in the survival of a baby that the trait is carried over into men as a useless aesthetic feature.

The reason men have nipples is not because they're important to females but let's focus this back to the conversation though: so what? Just because birth canals couldn't be used in deliveries doesn't mean they still wouldn't be there. There's already people that are dependent on c-sections and they still have birth canals.

I don't think we are in disagreement here.  However, if a species used an excessive amount of its brain, then that is blood that could be used to power muscles.  A species could get wiped out by prey if it's too smart for its own good.  Of course though, humans have clearly made it past this stage.  I am curious why you edited my original question before replying to it?  It changes the tone and grammar of the question.

Yes, I wanted to emphasize that I'm merely talking about a hypothetical and not something I believe will happen. I believe it definitely lies in the realm of possibility but it certainly isn't a prediction - as you pointed out any advantage allowed by abandoning vaginal births could carry a cost that is higher than the advantage.

I don't see how this relates, I don't know of a single baby that has been birthed by caesarean naturally.

It relates because I changed the norm in the scenario to people who naturally don't have foreskins. In both situations the norm is the advantage but an operation is available that allows somebody to bypass their natural disadvantage. With c-sections it allows births that couldn't happen naturally to occur (which is a significant disadvantage indeed).



As a side note, I'm really enjoying this discussion - thanks. :)
« Last Edit: March 08, 2009, 05:30:14 PM by midgard »

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Pongo

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Re: A few selective pressures removed
« Reply #27 on: March 08, 2009, 08:50:23 PM »
Do you know what's really funny about all this?  I voted, "I don't understand the question" so I could read the posts. lol.  Anyways!

I think we are agreeing on a many points, and I might be willing to concede the topic except for one thing that you may have over looked in your example.  If a mother, who's hips are too small births a baby who's head is too big and the mother dies, the genes are still passed onto the younger generation.  This is why you see people today that should have died under natural birthing circumstances live to birth again.  This has been going on for thousands of years and the only factor we have changed is that now mothers that should have died can now birth more than one baby.  Will this slight increase in surviving mothers tip the scales to lead to the loss of the natural ability to birth? No.  I related the topic to foreskin because either way, in either case, even if the baby dies in some instances, the same genes are being passed to the next generation regardless.  Neither case will effect the gene pool in any discernible way. 

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midgard

  • 1300
Re: A few selective pressures removed
« Reply #28 on: March 09, 2009, 04:03:16 AM »
Do you know what's really funny about all this?  I voted, "I don't understand the question" so I could read the posts. lol.  Anyways!

:D

I think we are agreeing on a many points, and I might be willing to concede the topic except for one thing that you may have over looked in your example.  If a mother, who's hips are too small births a baby who's head is too big and the mother dies, the genes are still passed onto the younger generation.  This is why you see people today that should have died under natural birthing circumstances live to birth again.  This has been going on for thousands of years and the only factor we have changed is that now mothers that should have died can now birth more than one baby.  Will this slight increase in surviving mothers tip the scales to lead to the loss of the natural ability to birth? No.  I related the topic to foreskin because either way, in either case, even if the baby dies in some instances, the same genes are being passed to the next generation regardless.  Neither case will effect the gene pool in any discernible way. 

I think that it's possible that the narrow-hipped ones could eventually tip the scale, if they died on their first child then exponential growth was impossible, now it's not so eventually it "could" tip the scale. The same is if a baby's head is too large and previously it would've died then the growth of the excessively-large-headedness-gene would be zero whereas now it's capable of exponential growth (it's not just mums that die in childbirth).

There are three main reasons why I very much doubt this will happen:
1. Primarily, I don't see the two advantages that lead to this awkward compromise (better bipedal mobility and increased intelligence) as such an advantage in our environment (at least compared to our ancestors' environment).*
2. The size/variation of the gene pool means that any advantage's effect on the population will be tiny. However, I also want to reiterate that the birth is a messy compromise and we could expect variations that require a c-section to come from multiple sources and not just a single source. Still potential partners number in the billions so even with the multiple sources the overall effect will still be tiny.
3. Finally there's the availability of c-sections, it's sometimes hard to imagine that the world won't keep on getting better and better and that prosperity won't spread further and further or that we could ever slide back into the dark ages but I'm sure that's been the case for every advanced civilisation.



*Too be honest I think intelligence these days probably is a disadvantage when it comes to reproduction:

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Pongo

  • Planar Moderator
  • 6753
Re: A few selective pressures removed
« Reply #29 on: March 09, 2009, 10:43:36 AM »
*Too be honest I think intelligence these days probably is a disadvantage when it comes to reproduction:


Aye, disadvantageous to the population, advantageous to me!  I don't want no babies... yet.


As for the rest of the post?  I guess we will find out in a few hundred thousand years.  I'll bump this thread back to page one on the year 200009 to see if anything has changed.