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Cesarean Births Could Be Affecting Human Evolution, Study Says (bbc.com)
CanadianRealist writes: Larger babies delivered by cesarean section may be affecting human evolution. 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, [according to estimates from researchers at the University of Vienna in Austria.] Science Alert reports: "In the past, larger babies and mothers with narrow pelvis sizes might both have died in labour. Thanks to C-sections, that's now a lot less likely, but it also means that those 'at risk' genes from mothers with narrow pelvises are being carried into future generations. More detailed studies would be required to actually confirm the link between C-sections and evolution, as all we have now is a hypothesis based on the birth data." Agreed, more studies required part. Cesareans may simply be becoming more common with "too large" defined as cesarean seems like a better idea. It's reasonable to pose the question based simply on an understanding of evolution. Like it's reasonable to conjecture that length of human pregnancy is a compromise between further development in utero, and chance of mother and baby surviving the delivery.
Well 0.36/0.30 = 20% growth and it's only been ~2 generations, if you consider that most of the 3% in one generation will have kids with the other 97% in the next generation it seems unlikely to happen this fast. It's probable that it's more routine and we're more cautious today, so borderline cases get the surgery now where they wouldn't in the past.
Live today, because you never know what tomorrow brings
Babies have been getting bigger for a long time.
This is well documented in medical literature:
- "These findings suggest that US and Canadian babies are getting bigger" https://www.ncbi.nlm.nih.gov/p...
- "We conclude that Canadian infants are getting bigger" https://www.ncbi.nlm.nih.gov/p...
- "Results presented in this study demonstrate that even when migratory effects are eliminated, a secular increase in birth weight is observed" https://www.ncbi.nlm.nih.gov/p...
foo mane padme hum
Yes. A study done at the University of Dublin concluded that if your parents didn't have any children you probably won't either.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Previous generations and marriages gave birth to a more traditional (old-fashioned?) household, where the father was the only provider, and the mother stayed home to raise children, starting at a young age (late teens/early 20s). Compare and contrast this to what we see today as more of the average, where both adults perhaps go to school, start careers, spend time traveling the world, and then start considering marriage and a family in their late 20's/early 30's.
And this is not meant to sound mean or degrading, but we humans don't exactly shrink in size as we get older, thus making pregnancy and childbirth that much harder on a human body that may be leaning more towards the overweight or obese range. Perhaps mentally, the ideal age to become a parent is mid-30s due to maturity/wisdom/financial status/etc, but from a purely physical standpoint, childbirth is likely ideal at a much younger age, which a younger body may provide a bit more flexibility when it comes to childbirth.
Sorry but that is currently impossible to test because their are insufficient babies born from IVF that have actually reached adulthood to really analyse that.
I would note that Louise Brown has had two children conceived naturally and her sister Natalie has had four children all conceived naturally. For those ignorant of the facts Louise Brown was the first IVF child in the world and her sister was the fortieth born four years later.
Note that shows the low levels of IVF babies being born in the early years of the technology and why there are too few IVF born adults to really conduct any study into their fertility.
There has only been one documented, (Poorly...), instance in History that Humanity physicality changed in a relatively short period of time- the 14th century. Starting in China, maybe, it spread throughout India, and then the Caucasus, into the Middle East and then north deep into the Scandinavian Countries. In two or three generations, half of the population of Europe died off due just to the Black Deaths. We don't know much about the other Civilizations.
One curious outcome can be seen in the clothing of the period. Europeans somehow got significantly taller over the following Century, after being stuck at Roman heights for over a thousand years. (Check out Suits Of Armor for a striking example.) Whether due to better nutrition; famines were common before the Plagues due to overpopulation and poor Farming practices, or whether there was some recessive Genetics going on due to past uncounted and unrecorded Plagues, is not now known. It's probably both; certainly poor nutrition can stunt inherited growth tendencies. And note that even without the Plagues, Infant Mortality bounced around 50%... Also note that this time was also the start of the "Little Ice Age", so Environment can't be ignored.
The European Countries in general, and the US in particular, have plateaued; 18 year old Males whose statistics have been gathered for centuries by those who like to play with War, have been tending to an average height of ~70 inches. In 1914, the average height of the Fresh Crop was ~67 inches.
But the growth in height is startling in some newly developing countries. In South Korea, it is now ~69 inches for Males. But in 1914, it was ~63 inches. Six inches is a pretty good jump, but South Korean women have jumped further- A gain of ~8 inches.
People have been growing bigger, but not at the same rates or at the same time. Generally, skeletal dimensions scale; taller women have wider pelvises. (Some populations in hellholes are actually getting shorter.):
http://www.npr.org/sections/goatsandsoda/2016/07/27/487391773/americans-are-shrinking-while-chinese-and-koreans-sprout-up
Cesarean births are still rare, and to draw any conclusion about general Evolution from their _recent_ trends is foolish. This is a damn stupid study; I suspect that there is an Agenda at work here. BTW, over the last few decades, the average US or Canadian baby has gotten slightly smaller:
http://www.wsj.com/articles/SB10001424052748704423204575017471267586344
You just came here to brag that you've sampled a statistically significant number of women.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Some breeds of dogs, bulldogs maybe?, HAVE to be born via C-section. The puppies can no longer fit the natural way.
You seem to suggest that it's not all that scary, not all that painful and not all that stressful. I encourage you to put a grapefruit up your ass and squeeze it out - and it still wouldn't be nowhere near the pain women feels during labor. Have you ever had a cramp? How long did it last? Try to prolong it for 6 hours every 5-10 minutes.
And why it's a bad thing women try to prevent their vaginas from being stretched out? Imagine that each time your partner gets pregnant someone cuts off one or two inches of your dick. Would you try to prevent that?
Medical liability cases are increasing around the world, and the cost of insurance is driving many people from the profession. (See articles)
My wife wanted to give birth at home, it was both very difficult to organise and extremely costly.
All her friends said she was mad; plan the date with your Dr. for a C-section, fast, painless and no stress waiting for contractions to start.
It's as much a matter of convenience for both sides as a question of baby size IMHO.
http://www.medscape.com/viewar...
http://www.spiegel.de/internat...
We have been de-evolving for a long time now. Lots and lots of "defective" people are living to reproduce who would have died without medical science (I am one of them). This ends up making the species genetically more poor each time.
Who would want to go through surgery if they didn't have to, and then go through a year long period of recovery?
Apparently, at least 3%...that's just the number that were granted, not the number who requested it.
http://www.cosmopolitan.com/he...
Just another day in Paradise
Anything that affects mate selection affects evolution... Mundane things such as wearing makup and shaving body hair are probably affecting evolution.
Laws are rules for the court, but merely a bottom bar to hit for life. Think beyond laws in your actions always.
This study appears to have multiple flaws: 1) A statistical increase in Caesareans does not mean a statistical narrowing of the pelvis. There is not a causal relationship. This is like suggesting that because relatively fewer people are having their wisdom teeth extracted today, our mouths must be getting bigger. 2) Even with a correlation between pelvis width and Caesareans, it does not mean those children or mothers would have died in non-surgical child birth. This is creating a binary relationship out of a correlation - or in other terms assuming the absence of a negative is a positive. Other factors: - The general guideline today (as I understand it) is that if you have had a Caesarean in the past it is safer to have Caesareans for future babies - this alone might account for the statistical increase. - Larger babies can be attributed to better prenatal health and nutrition. - The increase in Caesareans can be attributed to more women giving birth in a hospital setting where Caesarean is an available and safe option.
I agree. Unwashed lettuce can give you worms, and raw eggs can carry salmonella.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
I hope Trump gets rid of vaccinations while he's in office. These diseases are here to help rid our gene pool of bad genes, yet we keep trying to save those less fit. It only hurts our species in the long run!
We need NATURAL selection.
Jenny McCarthy is right -- even if for the wrong reasons.
Good deal. At the next Ebola outbreak, hop on a jet over to that location and help bury the bodies, but you can't wear any protective gear. If you have 'superior' genes, you should be fine, right?
Jerkwad...
You're messin' with my Zen Thing, man.....
Caesars carry risks.
Especially if you're a Gaul, or believe in Rome remaining a republic.
"That's the way to do it" - Punch
TRUMP 2016!!!
I don't think this is what he meant by "grab them by the pussy"
Not that I'm supporting Trump (he's more evil than Cthulhu, almost as bad as Hillary), but have you noticed how those 30ish women who accused him of sexual assault all went silent the moment the election was over? Shouldn't they be trying to bring him to justice? Maybe, just maybe, it was all staged false accusations as certain people like this kind of methods? See Assange, or what esr was tipped about.
The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
I'm curious about the vagina stretching.
Rule 34...
No sig today...
Err...I beg to differ.
I mean, most guys grow weary REALLY quickly of loose pussy and saggy tits.
Those two things are a big reason they divorce and 'upgrade' to a newer model after a few years.
Light travels faster than sound. This is why some people appear bright until you hear them speak.........
My wife says that childbirth (4 kids, so it`s a relatively good sample) is nothing compared to either kidney stones or appendicitis. There, stop propagating that myth, it`s not that bad.
Trump was in the white house a few weeks ago and he did shake Obama's hand. Coincidence? I think not.