The Briefing Room
General Category => Science, Technology and Knowledge => Topic started by: Suppressed on August 14, 2017, 01:00:53 pm
-
Caesarean births 'affecting human evolution'
By Helen Briggs BBC News 7 December 2016
http://www.bbc.com/news/science-environment-38210837
(https://ichef-1.bbci.co.uk/news/660/cpsprodpb/103E6/production/_92843566_thinkstockphotos-516285495.jpg)
In the UK, about one in four babies is born by Caesarean THINKSTOCK
The regular use of Caesarean sections is having an impact on human evolution, say scientists.
More mothers now need surgery to deliver a baby due to their narrow pelvis size, according to a study.
Researchers estimate cases where the baby cannot fit down the birth canal have increased from 30 in 1,000 in the 1960s to 36 in 1,000 births today.
...
It has been a long standing evolutionary question why the human pelvis has not grown wider over the years.
The head of a human baby is large compared with other primates, meaning animals such as chimps can give birth relatively easily.
The researchers devised a mathematical model using data from the World Health Organization and other large birth studies.
They found opposing evolutionary forces in their theoretical study.
One is a trend towards larger newborns, which are more healthy.
However, if they grow too large, they get stuck during labour, which historically would have proved disastrous for mother and baby, and their genes would not be passed on.
Historically, these genes would not have been passed from mother to child as both would have died in labour.
...
-
There was a time when wide hips was a plus for a female. It meant she was likely to give birth easily and safely.
-
There was a time when wide hips was a plus for a female. It meant she was likely to give birth easily and safely.
https://twitter.com/__dwightschrute/status/533889071635255296?lang=en
-
https://twitter.com/__dwightschrute/status/533889071635255296?lang=en
I wonder how successful he is?
-
I'd look at other possible causes before positing an evolutionary one; it hasn't been long enough and there isn't clear evidence that there is a significant overall effect on survival.
-
I'd look at other possible causes before positing an evolutionary one; it hasn't been long enough and there isn't clear evidence that there is a significant overall effect on survival.
Both my niece and my DIL delivered by cesarean and the reason was because they had really really big babies, not too narrow hips.
-
I suspect it has more to do with nutrition and baby size, but also ob/gyn love doing C-sections for myriad reasons.
-
I suspect it has more to do with nutrition and baby size, but also ob/gyn love doing C-sections for myriad reasons.
It couldn't possibly have anything to do with abortion on demand, could it?
-
It couldn't possibly have anything to do with abortion on demand, could it?
I don't know. On the face of it I don't see what abortion has to do with increasing c-section rates.
-
I don't know. On the face of it I don't see what abortion has to do with increasing c-section rates.
If c-sections affect human evolution, it would seem that having an abortion could have a similar impact.
-
If c-sections affect human evolution, it would seem that having an abortion could have a similar impact.
Well, I disagree that c-sections are affecting human evolution, so I guess I also have to disagree that abortion is. Or maybe some point you are trying to make is going over my head. :)
-
How long have c-sections been common? It couldn't have affect evolution that much.
-
How long have c-sections been common? It couldn't have affect evolution that much.
The article mentions 50 - 60 years.
Adding to what I mentioned above, there's the changing physical aspect of mothers of today versus 60 years ago. They were younger and fitter. There seems also to be a chiropractic aspect that is often ignored, I believe caused by increased sitting, that adjustments can help with; as far as I know that is a bit anecdotal though.
-
It couldn't possibly have anything to do with abortion on demand, could it?
I can't imagine how.
-
Both my niece and my DIL delivered by cesarean and the reason was because they had really really big babies, not too narrow hips.
I think that's becoming the source of the problem. My wife's doctor was very careful about that.
-
How long have c-sections been common? It couldn't have affect evolution that much.
They've been done at least since the time of Caesar.