Evolution…does it make mistakes or compromises? - Page 2

[Yummymummy74]

Originally Posted by PaganScribe

Addressing the title question:

Evolution doesn't have a brain. It doesn't make mistakes or compromises -- it simply IS. The individuals who are most fit pass on their genes; those who are not, don't. The end. If people have evolved to have large heads and painful childbirth, it is because that's what worked -- that is the "fittest" in survival of the fittest

Right evolution does not have a brain per say, however the fact remains that people are living today beyond their own timelines, people are being kept alive... cured of serious illnesses or living with illness via treatment and life prolonging therapies..and some of these people are breeding and this IS changing the gene pool that we rise up from.. I do not think there is any way to dispute that.. I do think that most of the womyn walking around today by virtue of evolution and survival of the fittest are the most primed to be bearing children I think mother nature herself in centuries past would have culled what was not considered optimum..but since the advent of this medical age in the last century at least, things have changed.. in the past what would have happened to a womyn who had a deformed or vastly disproportionate pelvic outlet?.. she likely would have died after days of un productive labour as would have her baby.. today?? well its a called c-section!

I am not saying that people should not have access to care... thats not my point at all.. but I do think this "pill for every ill" has really been more of a detriment to our gene pool at large than we will ever fully understand in our lifetime.. I would imagine that the impact of this is going to be very far reaching.. maybe not so much our children but what about our children's children? its really worth alot of thought I think.

[PaganScribe]

Originally Posted by Marsupialmuma

Right evolution does not have a brain per say, however the fact remains that people are living today beyond their own timelines, people are being kept alive... cured of serious illnesses or living with illness via treatment and life prolonging therapies..and some of these people are breeding and this IS changing the gene pool that we rise up from.. I do not think there is any way to dispute that..

Yes -- that's evolution. I don't think anyone is disputing that.

I do think that most of the womyn walking around today by virtue of evolution and survival of the fittest are the most primed to be bearing children I think mother nature herself in centuries past would have culled what was not considered optimum..but since the advent of this medical age in the last century at least, things have changed.. in the past what would have happened to a womyn who had a deformed or vastly disproportionate pelvic outlet?.. she likely would have died after days of un productive labour as would have her baby.. today?? well its a called c-section!

Yes. And now, having a disproportionate pelvis is no longer a tragically deleterious phenotype, and it is no longer selected against. So, by definition, the woman with the disproportionate pelvis is no longer less fit. It's not that evolution has somehow been overridden, or isn't working, or anything of the sort. Evolution is still doing exactly the same thing it has always done -- causing long-term adaptation to the conditions which exist. I am not arguing at all that the requirements for being "fit" have changed -- I think it's obvious that's true --merely pointing out that it doesn't mean that evolution has stopped, been overridden, or gone backwards (all things I've heard argued before). It might not be "natural" in the sense that the word is casually used, but it is still natural selection, and still evolution.

I am not saying that people should not have access to care... thats not my point at all.. but I do think this "pill for every ill" has really been more of a detriment to our gene pool at large than we will ever fully understand in our lifetime.. I would imagine that the impact of this is going to be very far reaching.. maybe not so much our children but what about our children's children? its really worth alot of thought I think.

Now, see, this I disagree with. Things would not be selected for if they harmed our chances for survival (in the long term evolutionary sense, not in the short term single lifetime sense). That's simply impossible. If something is deleterious to the degree that it is harmful to the ability to survive in the enviroment, it will be selected against. If it's not selected against, then it is no longer a severely deleterious phenotype (in the natural selection sense).

Obviously, if we have a drastic change in the way that we live (ie, all our technology is somehow destroyed) then what is deleterious will be redefined again, and those changes that you're talking about may be very very harmful in the long term. But any kind of drastic change in the conditions/environment could cause the definition of "fit" to be vastly altered.

[PaganScribe]

Originally Posted by mara

But by helping everyone reproduce we are hindering the natural demise of certain "bad" genes.

This is what I disagree with. If a gene doesn't cause us to be less fit, then it isn't a "bad" gene. If it were a bad gene, it would cause us to be less fit and we wouldn't pass it on. If genes can be "passed on with ease" -- then they aren't "bad" genes anymore (in an evolutionary sense).

I guess my point is that technology, medicine, etc. aren't "overriding" evolution. All they're doing is changing the definition of fit -- you can't make someone who's "less fit" be selected for. If you are more successful at passing on your genes, you are by definition more fit. You can't make evolution work toward things that hinder passing on your genes; it simply can't happen.

Maybe it's just a semantics issue and I'm too hung up on the specific words being used. Being a (former) biology teacher and scientist, I may just be a little too anal about the language that's used. Evolution is enormously misunderstood by the vast majority of the students that I taught, so I learned to be very, very specific about the language that I use to discuss evolution in order to minimize as many misconceptions as I could.

(Disclaimer: I'm not saying that anyone in this thread misunderstands evolution, merely that common misconceptions are what made me so careful with the language I use when I discuss evolution.)

[Galatea]

Re the head/pelvis issue: Human gestation and birth are a compromise between large brain size and pelvises designed to walk upright. In apes and monkeys, babies are born face up and can actually grab onto their mother's fur to help pull themselves out. B/c our pelvises are shaped for walking, our babies have to twist around in the birth canal and come out face down.

Re animals and cultural interference in birth: My mom sold a dog to a friend and that friend bred her. He did not want to whelp the puppies b/c of inexperience so she came to our house to whelp. Well, she was a single dog dog and treated like a person and spoiled etc. When it came time to whelp she seemed to have no instinct and was overwhelmed by the pain and refused to push and just quivered and wailed. All of the puppies were breech and were stuck and all died. Though part of it was surely the breech presentation, part of it was her complete lack of effort. She didn't push at all and we had to pull the puppies out. We have had other dogs who, b/c they were raised almost as people, could not even have sex properly. So I think "culture" can interfere even in animals.

Re morning sickness: I read that the more common morning sickness triggers are more likely to be potentially poisonous, like meat (it could be spoiled). Also, that pregnancies with high m/s are more likely to be successful (though this may simply mean higher hormone levels and thus obviously greater success).

[famousmockngbrd]

Carrie - good points, thanks for the posts.

So, let's say that our big brains were always our strong suit. That, and language. We aren't the biggest, the fastest, the strongest - but we are the smartest, and more importantly we are able to communicate our ideas to each other so our society can benefit from an individual's ideas. We evolved along these lines until now we have all these things we've created to augment our physical weaknesses. We've removed ourselves from the natural world, which was more hostile to us, and created an artificial environment which is better suited to our survival. So in isolating ourselves from natural influences and replacing them with our own, haven't we disrupted the normal progression of our evolution? I suppose it could be said that we selected for intelligence, etc. and our present environment is just the natural result of that, so we're still operating under the natural order of things. However, I do feel that we have stepped outside the normal checks and balances of evolution as it occurs in nature and it *is* possible for us to make choices, create situations, etc. that are not beneficial to us as a species, in the long run. Nuclear weapons is an example that comes to mind.

[Thalia]

However, I do feel that we have stepped outside the normal checks and balances of evolution as it occurs in nature and it *is* possible for us to make choices, create situations, etc. that are not beneficial to us as a species, in the long run. Nuclear weapons is an example that comes to mind.

Evolution in nature does not have the kind of checks and balances you are thinking of. As PaganScribe explained (really well, I might add), what makes a certain set of genes fit at any one time does not guarantee the future good of the species. It never has. You can see this all the time in nature with population booms and crashes. Or think of what happens to a species when a new predator that it has not yet adapted to comes on the scene. This is not outside of nature, it IS nature.

As humans, with the ability to think about our own choices and the impact they will have on the future, we can make decisions to do things that we think will benefit our species and those around us, like getting rid of nuclear weapons, and maintaining biodiversity and avoiding monocultures in agriculture that increase the likelihood that a new situation will wipe out an entire source of food, for instance. But that's not any more "natural" in terms of evolution.

[IdentityCrisisMama]

Originally Posted by PaganScribe

I guess my point is that technology, medicine, etc. aren't "overriding" evolution. All they're doing is changing the definition of fit -- you can't make someone who's "less fit" be selected for. If you are more successful at passing on your genes, you are by definition more fit. You can't make evolution work toward things that hinder passing on your genes; it simply can't happen.

Learning...

[IdentityCrisisMama]

Originally Posted by Thalia

As humans, with the ability to think about our own choices and the impact they will have on the future, we can make decisions to do things that we think will benefit our species and those around us, like getting rid of nuclear weapons, and maintaining biodiversity and avoiding monocultures in agriculture that increase the likelihood that a new situation will wipe out an entire source of food, for instance. But that's not any more "natural" in terms of evolution.

Learning...

[Quirky]

Just to add a footnote to PaganScribe's and Thalia's great explanations on evolution, and perhaps an unnecessary footnote on that - keep in mind that what we call "evolution" is the birds-eye view of a zillion things that happen to individuals. Over a whole lot of time, those things add up to shape the species. But as pointed out it's a continual process and one that isn't "over." So just because humans as a species have been evolving in a particular way doesn't mean that everyone who is alive today has the particular genes (whose expression is affected by environment - nutrition, disease, culture, etc.) that are more likely to lead to survival.

Also keep in mind that a physical trait may have deleterious consequences in one setting but beneficial consequences in another. So it won't necessarily be selected for 100% or against 100%. A good example is the set of genes that leads to sickle cell anemia. That set of genes confers some defense against malaria. So it makes sense that it wouldn't die out of a population that has evolved in the presence of malaria, even though it leads to disease.

So to take another example in the birthing context, just because in the past many women who were less fit for giving birth because of a disproportionate pelvis died, doesn't mean that the set of genes leading to a disproportionate pelvis would automatically be selected against 100% and that eventually we could anticipate that there would never be mamas with too-small pelvises giving birth to too-large babies. Because maybe certain mamas who had those genes lucked out and had great nutrition, a smaller baby who did survive, luck of the draw, whatever....and one of her offspring survived to pass those genes along. Maybe the set of genes was for a really big brain and the baby and her offspring grew up to be really smart, which was selected for. :LOL (Totally silly and inexact example obviously!)

All we can say about evolution and human birthing is that for most women most of the time birthing can go fine....because evolution works especially well on reproductive processes. But evolution works on individuals and not all individuals will be equally fit AND have equal luck in terms of culture, circumstances, etc. So one thing we should NOT do is imply that women should ALL have an equally grand birthing experience and that any failure to meet this standard must be their fault (or the system's) because evolution ensures that, left alone, all births turn out well. Even given all the problems with our birthing system in this culture, that just isn't true.

[WinterBaby]

Anyone read other articles related to this? Plants Challenge Genetic Inheritance Laws
Food for thought perhaps in what some organisms may do evolutionarily when conditions rapidly shift...

As for morning sickness.. I heartily reccommend a bit of it. It was the best tool I found for quitting smoking when I found myself pregnant!

And culture affecting dogs birthing? Dogs don't learn to birth by observing, nor do they understand our notions of it.. Although I think the presence of others can certainly interfere, especially strangers. That whole flight or fight mammal evolution I guess, lol. Sounds more likely the malpresentation both caused much unusual pain and never positioned a pup to trigger the reflex to push. Dogs don't Know to push... They just do when their bodies tell them too. I think there's a way to help trigger the urge to push with your fingers for a dog having difficulty, but not having been in the situation, no more info there.

[Rainbow]

Originally Posted by WinterBaby

And culture affecting dogs birthing? Dogs don't learn to birth by observing, nor do they understand our notions of it.. Although I think the presence of others can certainly interfere, especially strangers. That whole flight or fight mammal evolution I guess, lol. Sounds more likely the malpresentation both caused much unusual pain and never positioned a pup to trigger the reflex to push. Dogs don't Know to push... They just do when their bodies tell them too. I think there's a way to help trigger the urge to push with your fingers for a dog having difficulty, but not having been in the situation, no more info there.

I don't think it is about our culture or raising dogs like humans, I still think they are instinctive animals.
Humans haven't stayed out of the dogs life or process... a dog who has difficulty could very well be because of the massive imbreeding and genetic planning to create breeds of human ideal.
When our yorkie had pups (geese, I know.... that was long before I knew better) her first pup was huge and sat there until she was crying and wimpering (over an hour). Per the vets advice I helped a little on contractions, pup was delivered and she was an instictive pro with the rest. Her blood lines had been bred and bred to get the smallest possible pups, and then came one to large for her because of this imbreeding and planning in her line. She was 4 lbs and the "big pup" grew at full grown to be 7.

Of course I have no evidence for this idea... just my random thought based on one experience :LOL

[Keeper]

Here's what I've never understood about the argument re: human birth is more difficult because of our upright posture. At the end of pregnancy, the bones of the pelvis have spread to the point that an upright posture is very uncomfortable. Most women express that a hands/knees posture is the most comfortable. A hands/knees birthing position opens the outlet of the pelvis and can prevent many birthing "problems." So doesn't it stand that nature already figured this out on its own by causing a woman's body to naturally "regress" (for lack of a better word) to a quadruped state? I hold that difficulties in birth have less to do with evolution and bipedal locomotion, and much more to do with medical intervention/lithotomy position.

Sarah

[Mothra]

There is no evidence whatsoever that morning sickness, to any degree, is psychological. There were some really bad "studies" done in the seventies that suggested that women with "hysterical" personalities or bad relationships with their mothers were more likely to experience severe morning sickness or hyperemesis but they have never been duplicated and the data was corrupted in several ways. Plenty of people have tried to prove that it is psychological and have never been able to do so.

The idea that morning sickness developed as a way to alert a woman that she was pregnant makes sense to me, so does the theory that it helps women avoid things that may be harmful. I don't think that hyperemesis is related to morning sickness, I think it is probably caused by something altogether separate from morning sickness. Probably a combination of things that varies between women.

Childbirth was painful for women before the advent of medical intervention.

I totally agree with this:

So one thing we should NOT do is imply that women should ALL have an equally grand birthing experience and that any failure to meet this standard must be their fault (or the system's) because evolution ensures that, left alone, all births turn out well. Even given all the problems with our birthing system in this culture, that just isn't true.

[Mamabeakley]

I didn't actually have particularly bad morning sickness - but I did feel totally exhausted for 3 months. I really think the symptoms of early pregnancy serve the functions of letting the mom and everybody around her know something important is happening very well. It makes sense to me that there might also be purely physical evolutionary benefits, but the cultural benefits seem obvious and important to me. And I believe culture evolves, too. Ours is not the only possible culture any more than we are the only possible hominids. Our culture and our species have so far been very succesful, but very likely will not continue to be dominant or even exist permanently.

[IdentityCrisisMama]

Could you all talk about some common ideas I’ve heard from and evolutionary science perspective.

Some I’ve heard are:

“If babies (or adults) are supposed to be exposed to high levels of fluoride, it would be available in our diets.”

“If babies need high levels of iron, it would be provided in Breastmilk.”