To find the BBC article on research on c sections and evolution a bit off?

[bummymummy77]

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I find it a bit off. Yes it's science and cold hard fact but for some reason the tone got to me a bit.

And this is coming from someone who had a home birth and is very anti unnecessary interventions.

I can imagine it making women who've had c sections feeling like shite.

Seemed to me a little like the way it was worded is added to the quiet drip drip of c section stigma.

I mean, we've evolved past having enough body hair to survive in caves and eat raw meat, we treat cancer and intervene medically to save 1000's of lives daily.

At the same time I find it interesting and obviously most research will benefit mankind in some way.

What are other's views on it?

Mind you, that is partly because men's bodies don't do anything as interesting as giving birth to a baby.

"I put on 5 stone. ( at 5 2 this was way too much). I wish she'd have told me to lay off the cakes occasionally."

You actually needed someone to tell you not to put on 5 stone?

"I am surprised that there has been enough time for natural selection to be effected."

I am not. The increase is geometric, and C Sections have been around since about 3rd Century BC.

Assuming 1 generation = 25 years (very conservative estimate, as girls had babies in their teens for most of human history), that makes at least 96 generations. If I told you how many people 2^96 makes you would not believe me so best calculate it yourself. (And that assuming each make only 2 babies which, again is very conservative, since people commonly had numerous offspring for most of human history).

C sections have only been safe for about a century at most. Before then most women would have died either of infection or bled to death. It's only in recent years that c sections have become so common.

Before the invention of CS, both mother and big-headed baby would have died every time >>> Very low incidence of big-head genes passing downstream.

After the invention of CS, most big-headed babies and lots of mothers survived >> Much higher incidence of big-headed genes passing downstream.

I found it fascinating. Really not sure what is offensive about a piece of scientific research.

Am aware of the assumptions and margin for error in the work. Still fascinating though.

It's science. It's meant to be objective. Not judgmental.

Selection only takes one generation to have an impact. We're not talking about the evolution of a new species here, just one attribute becoming a slight bit more common.

The research the article is based on is interesting, and I also thought it was interesting to see a list of the author's other papers. Essentially he seems to be interested in why human's evolved to have such large heads even though there is a significant downside in mortality. I'd never heard of theoretical biologists before either, sounds fascinating. But theoretical, so he is presenting a hypothesis, based on data not strict facts, and a prediction not an observation.

I'd be wary about the data, at least in the West as one reason why more babies are born by c-section is the loss of knowledge among midwives in how to manage more difficult natural births without intervention. I had two c-sections and could say that without them me and my babies wouldn't have survived, but I've no real way of knowing if that is true. Better management of my labours could have resulted in successful vaginal delivery. ds had a transverse oblique lie which was obviously very tricky, but in the past although some babies with difficult positioning didn't make it plenty did. No way of knowing which would have been the case for me.

I don't think the article or the research are upsetting, and I was sad not to have had the birth experience I wanted. I would also not think any worse of my mother if she pointed out that without glasses I might not have survived to have children. It's just the truth, not an insult.

But theoretical, so he is presenting a hypothesis, based on data not strict facts, and a prediction not an observation.

What do you think are "data" and "strict facts"?

Oh, comma in the wrong place Lewji Should be '..presenting a hypothesis based on data, not strict facts' - probably not very well worded either! What I mean is that this is an analysis of a big but not specific dataset to construct a hypothesis, as opposed to a study of cause and effect in tightly controlled circumstances as a gold standard clinical study would be for example. So those saying it's science and therefore neutral and correct aren't entirely right. It's just an interesting theory demonstrated through theoretical (probably rigorous but necessarily limited by her data set) analysis.

The guardian picked up on this https://www.theguardian.com/commentisfree/2016/dec/07/caesarean-sections-mother-blaming-small-pelvises?CMP=fb_cif

CS is allowing heads to get bigger, freeing the species from the limit imposed by pelvic cavity size. That is a good thing.

It is quite possible that head sizes will continue to grow and there will come a time when most if not all births will have to be by CS. Again, nor a terrible price to pay if it means human species will get smarter and more capable.

Oh, ffs. Some people are obsessed with interpreting absolutely everything as being intended to blame women. Men are producing less sperm, a higher proportion of their sperm is abnormal. When they do manage to reproduce, their sperm is contributing to babies with monstrously large heads comparative to the rest of the human physique. Men and women are prioritising growing our brains over our physiques. If men have been dominating our world and the way it develops for so long, then this is all quite clearly more men's fault than women's. Or perhaps we could all stop being so bloody obsessed with blame???

"presenting a hypothesis based on data, not strict facts"

All hypotheses are based on data. Facts would be presented, not hypothesized upon.

Anyway this isn't a hypothesis. It is an observation that babies with larger heads are surviving thanks to CS. The logical conclusion is (which again we can observe) is that there are more people who make babies with big heads of their own.

Of course, you could argue that maybe nature would find a way to make brains smaller but simultaneously smarter if it were not for Caesareans enabling an inefficient process of uncontrolled head and brain growth to continue...

Nature has no incentive to make humans smarter.

Making us smarter would not make us have more children.

In places with freely-available contraceptives, nature may have an incentive to select for people who are a bit forgetful, as this could lead to them having more children than they would otherwise (but is unlikely to impact negatively on the survival of those children to breeding age).

I don't know, making us so "smart" we cease to reproduce might be doing the rest of the planet a favour.

I found it interesting - I really can't see where it's insulting or 'off' at all.

There's nothing too strange about this, certainly not requiring explanations that include sperm quality.

Human evolution has been driven by pressure towards large skulls (brains, really).
The female pelvis has evolved to accommodate it, as is the loosening of ligaments (and causing some women much pain during pregnancy). The pressure has been constant and newborn skull size is at it's limit, which is why human birth is so hard and dangerous compared to other mammals.
The gene variants for larger sizes already circulate, but their frequency has been limited by pelvic opening size. C sections removed that constraint.
This is the hypothesis. It predicts that baby brain sizes would increase when the constraint is removed.
It is now being reported that the data match the prediction, so the theory hasn't been disproved.
Until it can be tested in a different way. Or confounding factors can be better analysed.

There's a finite limit to how big our brains/heads can get though - our necks won't support anything too large.

Plus a large head would set us back in terms of the development of gross motor skills like sitting, standing and walking.

There is a boy at DD's nursery (they are both 2.5-ish), his mum and I were in the same health visitor group so I know them fairly well. He has a condition (not hydrocephalus as I know it has been ruled out) where he was born with a larger than "normal" head. As a result at the age of 2.5 he is still unable to sit, stand or walk unaided as his body just can't balance itself. The Drs are confident that as he grows and his body is more in proportion he will catch up to his peers, but for now he is comparable to a 6 month old baby.

Mentally he is absolutely fine with the expected speech and cognitive development you would expect of a child his age.

Sorry, should add my post was in response to the comment that head size could keep increasing and the majority of births by CS rather than vaginally.

But, Cave, with proper artificial support, large heads wouldn't pose a significant life problem. As long as large headed people continue to reproduce, head size is free to increase.

Well just need an exoskeleton. :)

I'm quite interested in this sort of thing as big heads run in my family .

DD's head was on the 98th percentile, and she was also back to back, yet she came out naturally (with the help of an episiotomy) five hours after the first twinge. Based on some of these posts, if I'd had a scan just before labour I may well have been recommended to have a C section.

My sister was also born naturally (10lb, big head). And my cousin (10lb 3oz, big head)...and my aunt only has size 3 feet.

Does this mean that as well as the big head gene we also have a corresponding massive hips gene ?? I am only a size 10...but very pear shaped.

lweji don't post pictures of my relatives on the internet!!

Lweji

eastpregnant it's not so much about "wide hips" as it is about having a wider pelvic opening. You could have massive hips but a narrow opening (leading to stuck babies) or equally narrow hips with a wider opening.