Study Explains Why Women Miscarry More Males During Tough Times

sciencehabit writes In times of trouble, multiple studies have shown, more girls are born than boys. No one knows why, but men need not worry about being overrun by women. An analysis of old church records in Finland has revealed that the boys that are born in stressful times survive better than those born during less challenging periods. The work helps explain why women may have evolved a tendency to abort certain males and could lead to a better understanding of miscarriages.

Comments

You are not in control

[NotQuiteReal]

The selfish gene wins.

Maybe it needs global climate change for the next step...

Re:You are not in control

[ShanghaiBill]

Deer will also disproportionately abort male fetuses during harsh winters. Offspring born after hard times are likely to be stunted and inferior. Even if they are disadvantaged, a female offspring is still likely to reproduce. But with males, reproduction is more "winner take all". This is certainly true with deer, where a superior buck will mate with many does. But it is also true with humans, were men are more likely to have either many children or none. So carrying a disadvantaged son to term, when he is likely to be unable to find a mate, is a waste of resources.

Re:You are not in control

[Viol8]

Sadly true. While I agree with most of what he says wrt evolution the way he says it really gets up my nose. He doesn't seem to understand that you don't get people on side by calling them idiots and trashing their entire belief system. That just gets their backs up and sends them off in the opposite direction to what you intended.

Re:You are not in control

[epyT-R]

I think he considers belief as part of the problem. It's an emotional attachment to a position that lacks evidence. People who get butthurt over being challenged are the ones with the problem. The problem is that today, the culture increasingly defends people with strong emotional positions and sensitivity at the expense of rationality and learning what is. The censorious policy that backs this is the primary threat to free speech.

The notion of end justified means is also part of the problem. Sure, showering someone with deference may get them on your side but it is for the wrong reasons. This is one of the major issues that shapes modern politics. Science is concerned with truth, regardless of politics.

That study used data from Finland's Winter War...

[He Who Has No Name]

...and one of the other things it found was that pregnant women who found out their loved ones were killed during the Winter War and Continuation War were more likely to have children who exhibited certain psychological conditions and behavioral pathologies.

It's the production line

[Todd Knarr]

Times of stress/trouble usually mean a loss of population. The arithmetic's simple: one woman can bear one child every 9 months to a year, while one man can sire multiple children in that same time. That means that adding female offspring at the expense of male will make it easier to recover the population loss. And of course sacrificing the least resilient male offspring favors the ones that'll survive the longest and sire the most children. The fun question is how the mechanisms that've evolved to make this happen actually work. Figuring that out's going to keep researchers occupied for the next century or two.

Re:It's the production line

[jimmydevice]

Ungulates can re-absorb a fetus during times of stress and insufficient feed.

Re:It's the production line

[DamnOregonian]

This is an unfortunate and common misunderstanding of evolution. It isn't remotely competitive. The environment is competitive. The method of evolution can indeed exist and flourish without any competition between fellows. Natural selection can find many ways to improve the reproductive fitness of organisms, and in many cases, too much intraspecies competition can indeed be a negative pressure.

Re:It's the production line

[RivenAleem]

My Father, a sheep farmer, would always be really annoyed if a fox hunt ever approached his land, and would go out and stop them entering his fields. He told me this was because sheep in distress could potentially absorb or abort the lambs under stress caused by all the commotion.

He was also a lecturer in Agricultural Science in UCD. I don't know if this information comes from farming anecdotes, or has a scientific background. Possibly both?

I am going to take this a step further

[Taco Cowboy]

Be forewarned, this message ain't gonna be Politically Correct

Babies born under hard times don't grown up to be homosexuals

If we are to survey the demography of various countries there is a clear pattern ... that countries with larger percentage of homosexuals, bisexuals, trans-sexuals, and all that (male or female) tend to be those that are relatively more peaceful, with more plentiful offerings of food, and all that

Not to say that there is an absolute zero percentage of baby born during hard times that grow up to be homosexual ... there are always the exception

Take China, for examples ... during the warring / turbulent years (since the late 1800's to the late 1960's) percentage of Chinese homosexuals were very low

Now? With relative wealth and comfort, new generations that were born into kinder and gentler surroundings are experiencing an increase of the homosexual population

Re:I am going to take this a step further

[EzInKy]

So are you saying that more homosexuals are born when societies can afford the expense of pursuing science and the arts?

Re:I am going to take this a step further

[reikae]

Since you didn't provide any sources, is this just your hypothesis or an actually observed pattern? If the latter, I wonder how the amount of non-heterosexual people can be determined? It's an interesting phenomenon if it's real, but do we know with any certainty if it is? Of course, one's sexual orientation doesn't matter unless I'm going to start a romantical relationship with them.

Re:I am going to take this a step further

[Anonymous Coward]

Be forewarned, this message ain't gonna be Politically Correct

Or true.

You just described and gave an example of a society in which outward displays of homosexuality was negatively received by society.

Take China, for examples ... during the warring / turbulent years (since the late 1800's to the late 1960's) percentage of Chinese who identified as homosexuals were very low because of the illegality and implications of coming out

Now? With relative wealth and comfort, new generations that were born into kinder and gentler surroundings are experiencing an increase of the homosexual population who come out and openly identify and express themselves as homosexual because of the massive change in how society receives them

Re:I am going to take this a step further

[Time_Ngler]

You could say that about every genetic trait modern humans have. What about short sightedness, then? How about an allergy to peanuts? Are these survival traits, too?

Re:I am going to take this a step further

[r_a_trip]

It is kinda sad to live in the time of prosperity when I know in times of adversity, we would be more resillient, more strong and determined. The comfy emptiness of prosperity just leads to boys being born and then growing without any inherent purpose other than being a part of the economical system. And the girls can afford to reap the fruits of prosperity while the boys wander confused trying to find a purpose in their lives. This is just an opinion to explain the current situation with lonely guys often working in tech or academia. Don't get me wrong, the desperate search for their purpose may lead to new great inventions and discoveries, but also the necessity has lead to great inventions and maybe faster. Living in prosperity is rather dull.

Says someone living in (relative) prosperity... So you want life to be harsh, unforgiving and generally hostile to survival, just so your purpose can become to merely exist and get your next meal before your peers eat it.

Wrap your head around the horrible fact that life has no other inherent meaning than to merely exist. You can live an empty (read: no inherent meaning other than to exist) life and have it be a struggle to survive or you can live an empty life and add all the frills to it that make it meaningful to you.

Either way, life is indifferent to what you choose.

Re:I am going to take this a step further

[Swampash]

Shortsightedness is certainly an aid to finding a mate :)

Seriously though, the presence of male homosexuals in a tribe gives that tribe an advantage over all its hetero-only neighbors. They're males who aren't competition for breeding partners. Competition for breeding partners is the #1 source of self-destructive crazy in any tribal group, hell just look at Islam.

Re:I am going to take this a step further

[Time_Ngler]

Why not make them asexual then? Gay relationships can have self-destructive crazy, too.

Gay tendency could be a side effect of other gene that is beneficial (or a combination thereof and/or along with a nurture component). For example, you wouldn't argue that blind spots are a survival trait, would you? And yet eyes without them would be considerably better.

Re:I am going to take this a step further

[Anonymous Coward]

I read a study done on tribes with homosexuals, what they found was that the homosexual man's grandmother had been a, shall we say, prodigious breeder, creating many progeny. Thus, it was theorized that homosexuality is basically a strong attraction to men that leaked over to men, the trait lives on because in women it is a powerful trait for producing young, and its effect on men is outweighed by that benefit.

Re:I am going to take this a step further

[ShanghaiBill]

Since you didn't provide any sources, is this just your hypothesis or an actually observed pattern?

Even if he provided sources, they don't prove his hypothesis. Peaceful, prosperous societies may have more homosexuals, or they just may be more tolerant so more homosexuals come out of the closet and are move visible. The latter seems more likely to me.

Re:I am going to take this a step further

[Anonymous Coward]

Meanwhile, remember to thank Alan Turing for his contributions to the computer you used to post that.

Selfish gene: highly misunderstood term

[140Mandak262Jamuna]

Richard Dawkins' book the Selfish Gene is probably one of the most misunderstood book titles ever. Dawkins was too clever for his own good, and you need to read his entire book to get to what he means by that term. He most definitely does not mean "there is a gene that makes people/organisms selfish".

He goes after the chicken and egg problem. Most people think of the egg as chicken's way of making a new chicken. But it is equally plausible, the chicken is merely the egg's way of making a new egg. We think we use genes to more copies of ourselves. Can we consider the genes are making more copies of themselves using us, the humans as a species, as mere replicating machine or incubator?

The question he poses is, "Are genes our selfish way of making more copies of ourselves? Or we are merely replicating machines under the control of the selfish genes?". He takes half the book to make people understand the question. Then the other half to prove, indeed the genes are in control and we are mere replicators. Some of the genes we have in our bodies have copies living in other species, other genera. Some of them are 100 million years old. The genes as a whole are the selfish ones vis a vis the organisms as a whole. They survive. We don't. We as individuals, we as species, we as genus are dispensable. The genes, as a whole, are selfish compared to the animal bodies they live in. The Selfish Gene. Not gene for selfishness.

Study explains nothing

[Dan East]

This study "explains" nothing.

Such a pattern would provide an evolutionary explanation for such culling. It “might be adaptive,” Lee says.

An "evolutionary explanation" isn't an explanation. WHY do more male fetuses die than female during stressful situations? What is the actual mechanism causing this to happen? The answer to that is an "explanation". Further, given the relatively long time frames involved in human reproduction, how would this trait have evolved to cover such a large percentage of the population when it is only needed during stressful situations?

Maybe males require more resources from the mother as a fetus, or maybe the difference in hormones is the tipping point that causes more male fetuses to die in these situations. But just because it appears to be beneficial in some way in the vast scheme of things does not mean that it exists because it is beneficial evolutionary or was selected in some way.

Saying "we found it is beneficial for less male fetuses to be born during stressful situations" does not mean "less males are born because it is beneficial during stressful situations".

Re: That study used data from Finland's Winter War

[He Who Has No Name]

Yes. The data was showing that a traumatic emotional event for a pregnant mother was literally causing neurological effects in the developing fetus.