A question about adaptation, human diet, and 10,000 years of stagnation.

Robert, good points and questions. Any of my late night ramblings of universal truths should be viewed skeptically. I still think I am right ;), but if you’d like to pick my reasoning apart further, my assertions were based on my recollection of my interpretion of Noam Chomsky’s work on the subject of linguistic evolution and bio linguistics . I tried to look up the sources I recalled and after 20min renemembered that guy has written more beautiful intellectual rabbit holes than I can afford to dive back into right now. And please remember that however you interpret what I say on this touchy subject, I think we should be respectful of rocks and space itself, so of course I am for respecting all people and all our fellow animals.

As I recall though from my college anthropology classes (15yrs ago;), large global atmospheric events like volcanoes occurred approximately 70-100k yrs ago and 15k yrs ago respectively. These created bottlenecks of human populations that is reflected in the rna record, we are all descendants of survivors of that first catastrophe. Since people from all over the world have similar capacity for complex language it would seem this was selected for before the human diaspora out of what is now Ethiopia.  That or it was a recessive that was present across the entire population, which seems less likely. My understanding is this diaspora across Eurasia and beyond started a few thousand years after the 100-70k yr ago catastrophe. I would favor the theory that this first catastrophe selected for those groups with enough people  with the capacity for complex language to have developed food storage and multigenerational knowledge of the landscape and some concept and way to communicate that stuff hits the fan sometimes and how to plan for many seasons of famine. It seems obvious that an ability to communicate complex information of generations would lead to natural selection on a community level for those that reinforced and rewarded behaviors and traits that were resilient, opportunistic, and foreword thinking, among othe traits that would allow a population to survive the long winter.

The 15k event wiped out all but a few isolated ideally located and prepared populations of people totaling in the thousands, and likely took out any remaining peoples without highly complex multigenerational and societal knowledge of how to survive, like our Neanderthal cousins who many of us still share partially common ancestry (4% average in Europeans, most of any large group).  

Anyhow, in relation to diet it seems we evolved to be omnivores that are prone to noxious invasive ness due to our mental capacity to maximize our acquisition of protein rich, sweet, fatty foods. It seems like everything in moderation so you can have as much diversity of fresh or at least chemical free Foods as possible would be the ay to go, and  fermentation and preserving for lean times.

Good question. (Its late so i will probably have to edit this a bit later on. Is there no way to have a text in writing saved before publishing ?)



First of all. I really don't understand why we humans are supposed to have stopped evolving Why of all creatures on earth should we be the exception? This idea smacks of 'special status'. For such an exceptional claim, i like to see exceptional evidence.

BTW The only species that have stopped evolving are extinct ones. Looking from that perspective,..... Any claim that we have stopped evolving is at least as extraordinary. MORE evidence please, otherwise this idea is a variation on "we are in the middle of the universe".





The way evolution works is that in a given population some genes give the individuals having them a competitive advantage all else being the same. The bigger the population the bigger the chance that some gene variant will pop up that has a mesurable effect on the survival chances of that individual. However it will take far longer than ever before in the past before all of mankind has acquired that gene.

What is definitely happening is that changes in our abiltity to build succesfull societies (language and social skills f.e.) are added on top of purely physical (including dietary) evolution.
Societies have become very succesfull in the short turn. To stick to food, (you can easily broaden the argument) food acquisition, food production, food preservation, food safety, food  hygiene have become much better than in the past. Just look at population statistics.

What our numbers allow us to do is specialise and diversify. Most of us have just to be good enough at a certain job to earn enough money to keep ourselves and our family in food, clothes, etc..... It does not matter so much anymore if you happen to have bad eyesight so you don't tiggers coming. Others in society have eliminated most tigers. So for most of humankind, good eyesight in the distance is no longer as big an evolutionary plus as it used to be.
Instead we have to be smart enough to avoid being eliminated by competing humans, From that perspective we gain if we live in a group that includes people who see really well in the distance (to shoot tigers, very unPC ). We gain if we live in a group that have people who don't get seasick, those are the obvious fishermen and mariners, ..... Diversity is top.
Getting along with your fellows is for humans the most pressing evolutionary drive. Any attributes helping us in that regard - brainpower, language skills, .... - evolve very fast, it seems. Our cultural evolution is even faster.



Apply this to food.

We change plants and animals - we became a (perhaps the) driving force in changing/skewing the genepool of species we have a relation with - that is on top of any 'natural' evolution. Species we 'like' don't go extinct easily. In fact, there have never been as much cows, camels, goats, sheep, etc..... nor have these species ever been spread so much - many over almost the entire globe.
It is not just domesticated species. Cockroaches, rats, lice, sparrows,... evolve in tandem with us. They influence our evolution.

We cook food, so we can eat food that we otherwise would find difficult to process. The result is that our gut has not to grow longer and bigger - we have not adapted our gut, we evolved a better brain. A better brain allows use to 'spend' less energy in our gut (and more thought on food. Just look at gutsize of chimps or gorilla's compared to their brainpower.
We can refrase the original question a bit. Perhaps our bodies are not yet adapted to what we do with our food or even Perhaps our gut bacteria are not adapting fast enough to cope with the changes in the things we do to our food. Gut bacteria evolve very fast compared to us. Newcomers in an area can have bad reactions to local foodstuffs but if they survive the initial diarea they (or their gut bacteria) adapt after a while. The classic example is Europeans going to live in the tropics. Lots of them died, some were succesfull enough to have kids.


I don't think we have a specific, predisposed diet in our genes as a species. We have proven to be very adaptable mostly trough culture. That is not to say that individuals have no genetic disposition to certain foods.
Historically speaking individuals and societies with lots of different foods available, have less chance to suffer famines, they remain healthier, ......

An european without alcoholgene had to drink contaminated woter. Chinese drank tea, not so much need of an alcoholgene.
Europeans used milkproducts. That's a way to make environments usefull that f.e; the Chinese historically did not use. Historically, mountain regions in Europe are productive agricultural regions (wool, chease, butter, milk and meat). The classic Chinese culture was late in entering the mountains - so no milk processing gene there yet.


In answer to the question of R. Ranson,

Yes we have adapted somewhat to the agricultural production of the regions we live(d) in. Mostly trough culture and a bit (as fas as the evidence goes) trough actual fysical adaptation. I suspect - but found no evidence - that our gut bacteria change and evolve in our lifetime - it seems logical to me.
Societies in general are doing well enough with their traditional food. Individuals might suffer unless they find foods that help them (perhaps that's why we like to dapple foreign cuisines?). Foods or cooking methods are adopted into the cuisine if advantageous enough. Think patato, maize, etc... becoming standard foods in europe.

It is important to note that 'traditional' food might have helped people to stay healthy enough to reproduce but that does not mean that this food helps you to live 50 years in good health past your reproductive years.


I think that a varied diet will keep me going the longest and in best health possible.

Ahhhh... Chomsky.  I generally like his stuff, but tend a bit more towards anarchistic models to his that are more socialism.  Pretty dense reading, to be sure.  I have to be in a very certain mood and state of mind to even contemplate picking his work up.  The thing that I find about a writer like Chomski is that I have to read the work though a socialist lens, then it makes more sense to me.  I have to put myself in his shoes, so to speak.  It is hard to refute the avalanche of information that he inevitably puts forward; he is definitely one of the most intellectually dense conceptualizers that I have ever read.

The most recent information I have read is that there were people in Alaska 25,000 years ago.

There are many things besides volcanoes that caused large bottlenecks in the human population.  The ones that come immediately to mind are glaciations and meteor strikes (both of which might be the subsequent cause seismic/volcanic activity, or might not).  At any rate, there is evidence that certain substances and certain environments promote brain activity (synaptic/neurotransmitter function) and other's that impede it.  I think that it is very likely that certain environments and foods and medicines in our distant past had great influence on how we evolved as the thinking beasts that we are.  I'm just not very convinced that this happened recently.  

When it comes to diet, I have to think that food storage is important in the terms of disaster planning, and dealing with severe events like famine, but it is not what defines our dietary needs, or what is ideal for our nutrition.  It may have allowed us to survive certain events so that we could continue to evolve on this path, but... there are a great many non temperate societies that thrived just fine without a food storage system.  

As was pointed out, we are the only hominid (or other creature for that matter) that seem to need or desire to cook our food.  How this came to be has been suggested by us being scavengers, who, post wildfire, would come across burnt carcasses that we could gain protein from easily.  Fire would become more essential during the ice age, obviously, and this was probably a defining factor in how we evolved toward cooking our food; eating warm food is a heck of a lot better than frozen food.  The evolution of fire skills might have been an essential part of our evolution.  It allowed us to not only produce this incredible element at will, but we could defend ourselves from predators, drive prey, purify water, dry and warm ourselves, and conceivably more importantly, it allowed us to sit up late at night and tell stories.   That doesn't mean cooking food is good for us, but it's been the cultural norm for a long time, even in the jungle.  How long we have been creating fire with sparks from stones, or friction from wood, is up for a whole other can of worms debate, but I would hazard to say that when we were learning to do that, we had pretty complex minds already; and we have been doing that a much longer time than 11,000 years.  

Lascaux is famous for its Palaeolithic cave paintings (estimated to be at least 15,000 years, but likely older), and if you look at these works you will notice that they are by no means simple works of art; nor are the works of the ancient Australian peoples which might be far older (closer to 30 or 35,000).  

I have a hard time thinking that the neolithic was some kind of dietary boon.  While we did stabilize many of our more temperate cultures to a sedentary/civilized life, I think that our diet was likely drastically reduced in variety by our reliance on cheap grain carbs and our energy focus on animal husbandry.

At any rate, If I was to hazard a guess, I would say that our brains were probably fully developed for language well beyond the 50,000 year mark.          

     

Out of all the plant family it seems like almost all humans now eat from the grain/grass family, the bean family, cabbage family, rose family and a few others.

And when it comes to animals it seem like it it also centered on the Bovine family (goat, cow, sheep, buffalo, antelopes).

You know, with all the points you all make, I think I should go back and check my dates and population numbers, I think it may have been a bottleneck of 15k people 70k yrs ago.

I ran accoss this article Gut Bacteria Can Fluctuate With the Seasons. Researchers studdied the microflora in the Hadza tribe (same tribe that was studied in the last two articles I posted). They found that the gut bacteria/yeasts fluctuate with the seasons due to the seasonal diets of the Hadza people. And, that the microorganisms that come and go with the seasons, are the more rare varieties that just aren't found in civilized countries. It appears that our diets that are largely the same year-round, never give these rarer mircoorganisms room to grow.

This gives me hope that, perhaps, by starving the bad bacteria/yeasts in my husband's gut, and increasing the amount of unwashed fruit and veggies in his diet, might allow more gut-healing microorganisms to colonize his gut. And, that by doing the same with my kids, I might prevent them from also getting Crohn's or other bowel and autoimmune disorders. It also gives me hope because it shows that we CAN change our gut biome, and my husband really needs his changed!

I found the last three paragraphs of the article really fascinating, too.

By comparing microbiomes around the world, Dr. Sonnenburg said it might be possible to understand how gut microbes linked to industrialization are affecting people’s health. He has hypothesized, for instance, that they may be causing chronic inflammation.

In their new study, the researchers found that microbes in the guts of Americans make more enzymes that degrade mucins, compared with those in the Hadza. These enzymes allow bacteria to harvest carbohydrates from the mucosal lining of the gut, rather than from plant fiber.

The result? “If you’re not feeding your gut microbiome with dietary fiber,” Dr. Sonnenburg said, “your gut microbiome is feeding on you.”

With all the holes in my husband's intestinal walls, I wonder if he's got--or had--way too many of these gut-wall-eating buggers in his intestines. I'd love to know what food the Hadza ate to feed the non-gut-wall-eating bacteria and yeasts!

After reading all, I think I have something new...

r ranson wrote: I'm getting confused by contradictory information.
in hopes of keeping things clearer in my head.
Anyway, all this stuff is confusing me.

Let's change from a top - down logic to a bottom - up one!
Why do book writers bring such or such information? Why do they choose different informations to sustain their ideas?  

r ranson wrote:Why is it claimed that our ability to digest food hasn't changed in 10,000 years when it changes for other species in less time?

The greeks were already learning the art of defending one idea, and then defend the opposite idea.... Claims are not based on what we can expect.

r ranson wrote:It appears that the Modern Western diet isn't working.
Do we really have to go back 10,000 years to find a diet that our bodies thrive on?

By "diet", do you mean food? Or digestion? Or assimilation?
What is it that is not working?
In this thread, it has been talked about an amazing variety of themes such as the microbiome, genetics, evolution and transformation of our food sources....

And still there is one important part of digestion that has not been talked about.... This is the part I want to talk about....

r ranson wrote:According to my reading on SCD...

With a lot of references hehe... Read something else and they also have convincing references... Read about the success of the starch diet!

r ranson wrote:Why is it claimed that our ability to digest food hasn't changed in 10,000 years when it changes for other species in less time?

WHY.
This is the right question!
Because they transmit in words and to humans. -> Top-down approach, head first!
No human will pay attention to what they are told with clinical proofs only, our cortex want the author to JUSTIFY everything.

But as it has been said here, bananas instead of wheat worked long before creating the word "gluten"... Some surgeons washed their hands but who took Semmelweiss seriously before knowing about microbs? The past can sometimes seem so stupid nowadays, but we are still stuck in our cortex and we have not changed our "genetics" so much : we need proofs again and again!
Cortex dominance.
This is the last 100 centuries stagnation... We are in the ulcer factory forum and we would doubt the impact of contradictory ideas on us? All those diets send contradictory ideas upon us!

r ranson wrote:It appears that the Modern Western diet isn't working.  

So.... where do I see it differently? That it is more than diet.
What is diet? A collection of what we eat? A meeting and fusion of two worlds?

What is not working? I agree with most statements made here about issues with the gutbiome, about aflatoxins, etc. But it is not all about food, and not even all about pollutants. We have to speak of the INTERACTION. Also about accumulation of different factors, and about the impact on US, OURSELVES. What's about the so-called "rest & digest" state? What's about the vagus nerve, about the para-sympathetic system? The autonomic system is the only system no human seem to be able to speak about as clearly as we can speak about any other system in our body! The main difference we have with other animals is that our cortex has modified the fluidic wavy functionning of the autonomic nervous system, though we still have it and need it and use it. We have all heard that we have a sort of "brain" in both our heart and our guts.... though we limit this to some obscure instincts and intuitions. Because the problem is that this brain does not have words as a language, but "talks with "what has been called the felt-sense or the unspoken voice. Which translates into emotions in the limbic brain, and into words in the cortex. Tri-une brain.

So what has changed for humans is that we had a bottom-up approach in life, and that we now have mostly a top-down approach of life. That is why SCD, and all diets and all other ideas, will target your cortex for their message. And for doing this, they have to select among all the information, what will support "scientifically" the idea they give you. Yes they give you an idea, and then you have to TRY it. Which means that you will ASK YOUR BODY. "What do you think, oh my gut?" - Sorry - "What do you FEEL, oh my gut?"

Now, just a bit of what I remember, just for your cortex to be happy: it has been proved that a sympathetic or para-sympathetic state can alone modify the gut biome. Then if you list all the different reasons making our bodies react to food, and pollutants etc, you can summarize it with one word: attack. Which means defense, and then you have a spiral feeding itself. I say spiral and not circle, because the solution is not to jump to another circle, but to travel the spiral the other way. What is wounded in too many people is our resilience. We just need to increase it slowly and without changing track in the spiral. Just remember the old vinyls when the spiral was hurt. We are still vinyls like 10.000 years ago, and we will never become CDs!

Conclusion: your cortex can have access to a lot of information, but is not the king for choosing. Give the right job to your cortex, fill your disk. But the software that will elect and guide your choices is the autonomic system. That is what happened to all those big scientists we were told about, who got their brilliant ideas out of the lab. That is what happens to all champion chess players, who can find the best solution in an instant. You will not notice this system in you so easily. because it transmits informations to your other parts of the brain, and we tend to listen to words. But we all know we can "read between words" (and are also champions at making mistakes at this!).

If you want to notice some direct informations, pay attention to the felt-sense. Feel your guts, see with your heart... expressions are not lacking and they all refer to what is, historically, phylogenetically, the master of life (after the cell probably). The autonomic nervous system was the first nervous system on earth. And this is what has not changed those last centuries, even those last millionaries and more than we can count. Each evolution is like a bigger russian doll around the smaller dolls: you see the outside one, but the others are still all here.

So ok, find a diet that attacks your gut less, but then also repair the resilience that was lost, and it will help you repair. This is an egg or hen story there. Both alternate for evolution, even for our personal evolution. Do not stay stuck on arguments they use to try to convince you in any method/diet. They wrote their books because it works for some people. They also try to tell you who is likely to benefit from it. But they usually end up very convinced that everybody would get benefits! Instead of trying to guess, get an idea of all sorts of diets, they go from all plant to all animal, they go from all raw to all cooked. Then try to figure out what correspond best to you, and then ask your body. Then dive into the somatic world! This will restaure what humans had 10.000 years ago! Even spiritual healing is acting upon this system in our body, as we have no direct access to it except through the use of beliefs and imagination and creativity. Breathing techniques also are meant to modify the state of our autonomic nervous system. And you surely know that your level of quietness, calm, has an influence of your guts. This alternates like waves, and some people are not surfing the waves as well as others, and get stuck in a not enough rest & digest state. This can be changed, I am working at it actually! We all are, but the more aware of what we do, the better it works.

So yes we are in stagnation, but not genetic nor in history, just in our own nervous system.
We need more hugs a day than books and even apples!
e-hugs to you all!

Mmm more fermented foods ?
Beer and bread for me then :-)
after all beer is just liquid bread ( T Pratchet)
:-)
David

4 other points:

- About gut biome, you would have to separate the cases of the 2 intestines!
You can have the right bugs at the wrong place...
Our upper gut should be more or less sterile, which is not the case of the colon.

- As we need to get our biome from the mother, changes are transmitted, though it is not genetic.

- Also, if you want your upper gut to stay free from bad bugs, you need a very acidic stomach, stimulating thus a very alkaline intestine, thanks to pancreatic and liver juices. This is what kills the bad stuff coming from outside. For producing enough HCl: You need enough chlore, like from salt, and enough phosphorus and stimulation from bitter leaves. Meat also stimulates acidic HCl. You also need enough exercise to have the right amount of CO2 in blood.

- Your levels but also your ratios of zinc and copper will act upon your resistance to fungi or bacterias. And minerals can become bio-unavailable. And some toxic metals can take the place of the right ones, modifying your mineral balance, which modifies your organ functions including thyroid and adrenals, and your metabolic rate.

Erwin Decoene wrote: Any claim that we have stopped evolving is at least as extraordinary. MORE evidence please, otherwise this idea is a variation on "we are in the middle of the universe".

Yes, I agree with this observation on the idea of a 'special status' as the origin for this sentiment.  It's been noted before that Darwin had to "fit" his evolutionary theory into the Victorian sentiments of the day, thus the idea of "basic, lower" forms or variants of life, struggling (on a population scale) towards "perfection".....a linear trajectory of creation that matched well with "fallen" man ascending towards "heaven".  

Somewhat as a thought experiment and including the discussions of gut microbes, I add to that layer of microbial involvement the notion that not only is our skin covered with microbial life, but our very cells have mitochondria, which share evolutionary lineage with bacteria (and of course plants possess chloroplasts which share that same microbial history).  So microbial populations evolve, the climate and larger environment evolve, and we are not separate from that.....even our own efforts to insulate ourselves from the larger biosphere/multiverse will, in the end, require a leap of evolution since we are not adapted to that way of living.....yet.  So, evolution in this general regard is just cyclical....adapting to whatever direction the environment has been pushed and is prodding all other life including Homo sapiens at this particular point in time (and what is "time"....yet another concept difficult to pin down).  Additionally, with the degree to which microbes are directly, residently, involved in our own health and existence, who is in the driver's seat?  Are my thoughts really "mine"....or are the microbes collectively suggesting "I think you want pancakes for breakfast!......"

Finally, many mutations, as a phenomenon at the DNA level, can be just 'neutral'---not really conferring advantage or disadvantage.  But that in itself often assumes a static environment.  Sometimes neutrality reveals itself as something else under changed environment.

John Weiland wrote:

Thekla and Joseph, that's an interesting angle.  I've known about lectins strictly for their carbohydrate binding ability, but here's a reference to their role.....along with complex carbohydrates....in allergy sensitization:  

http://www.jacionline.org/article/S0091-6749%2813%2900262-5/pdf

I have downloaded the link and it looks really interesting.  I'll take a look at home tonight.  Thanks for posting.

I think the lectin thing is currently considered a "fad diet", but they can make a fad diet out of anything, and though the plant paradox may be on the extreme side for the mainstream population,I think many people really need that level of lectin limitation.  One thing they say is that gluten and phytate/phytic acid are both lectins, as well as another far worse compound in wheat bran, and that the more common allergies and sensitivities are or may be related to lectins.

I'll try to summarize the big events in human history from the book I mentioned above.

Great topic

Brief synopsis of "four cataclysmic changes in the human diet"  from Steven R Gundry's book: "Plant Paradox"

1) Agricultural revolution, ~ 10,000 years ago, when hunter gatherers  grains and beans became staple foods.

2) A mutation in cows ~ 2000 years ago.  He is referring to the emergence of the A 1 casein in northern european cows.

   (no mention of the earlier change when some populations of adult humans became able to digest milk)

3) New world foods introduced to Western Europeans.  (Highlighting the euro-centric bias of the author, clearly the new world people were already eating new world plants)

5) And with the industrialization of foods, we of the industrialized nations,
          have increased consumption of wheat corn and soybeans,left traditional methods of food preparation behind
          have ceased to prepare our own foods, eat at restaurants and buy "ready to serve" meals
          have increased the use of petro chemicals on our food crops
         

So, there it is, the historical perspective I said I'd present.  You can see my bias against the author's own ethnocentrism in my comments. but I do think he has plenty of other useful information about digestion and immunology in the book.

And, being as he did a lot of heart (and other organ) transplants, he had to learn a lot about immunology, and that is where I think he has a valuable perspective, especially since auto immune conditions are so common, and many of them manifest through inflammation in the gut.

His book is being called a fad diet based on pseudoscience, but I have learned a lot from reading it, and my brother in law is benefitting greatly from following many of the recommendations.

I think some people are more sensitive than others to various compounds that appear in our foods, and so as individuals we need to learn about our own health conditions and challenges, Kind of like when we consider our ground be it garden or broad acre, we look at prevailing conditions/ vectors, we consider our projected uses/ zones, and we understand that our own plot is like none other, and these considerations idiosyncrasies, strengths and weaknesses are more  important than historical or contemporary, scientific or traditional policies.

I still think this is a great thread.  I only have to read that article John Weiland posted about 5 more times before I understand it well enough to do anything other than nod my head and say uh huh, uh huh, uh huh.  

So when we travel, we are often cautioned not to drink the water. We often do anyways, and are made sick by either the organisms in the water or the different mineral profile.

If we drink the local water long enough, though, it no longer makes us sick, and in fact, drinking our water from home, which we previously thought normal, might make us sick.

I am pretty sure that's a solid example of the gut microbiome adapting itself to dietary change in a really short period of time.

I would venture to say that because of this rather rudimentary example, along with the fact that we know that the population turnover rate for bacteria is monumentally faster than that of humans, that the idea that the gut microbiome not being able to keep up with human evolution is unlikely to be supported by any kind of evidence.

I actually don't ask my gut how it's feeling. If I need to know how it's doing, a look at my stool will tell me. Also, smells, cross-sectional and overall shape and size, and movement frequency inform me of much that I might want to know about my overall health.

And gas. I am probably not the only one to notice gassiness as one of my first signs of dietary distress. The smell of your gas can give you an idea as to which bacteria might be responsible, or what bacteria/food interaction.

My heart doesn't talk much, except for that beating thing it likes to do. Probably a good thing. I only have one, and I hear that if it doesn't keep it up, neither will I.

And again, if genes are lost over the course of an organism's evolution, unless they remain as recessive genes, they are lost and will not come back. So in that way, we are radically different from humans of 10,000 years ago, and our gut microbiomes are an order of magnitude at least further along.

As to evolution, please remember that the specific mechanism by which new traits are chosen is reproduction.

Except for love, which in mammals is suspected to have overridden early mammal reptile-brain selfishness to promote care for the young, which sacrificed the parents well-being in favour of the next generation to enhance the passing of genes down the line, it doesn't matter how much of an advantage was offered by a new trait; if it didn't help to make more offspring or keep them alive to reproductive age, it wasn't an evolutionary advantage.

I welcome dissenting opinions, but that's how I see it.

-CK

Chris Kott wrote: the idea that the gut microbiome not being able to keep up with human evolution is unlikely to be supported by any kind of evidence.

I actually don't ask my gut how it's feeling.
My heart doesn't talk much, except for that beating thing it likes to do.
Except for love, which in mammals is suspected to have overridden early mammal reptile-brain selfishness
I welcome dissenting opinions, but that's how I see it.

Chris, what did you think about the above I wrote?
There is evidence that any theory make people choose the scientific proofs that will make it coherent. It is just that we need coherence between the 3 parts of our brains. For me, this is enough to understand why SCD and other diets will use the shift we know about. towards agriculture, to support ideas that are otherwise only supported by clinical evidence for some people! And it is enough, same for all diet, all plant or all animal, it suffices that it works for some people to justify that they might use it! But it might challenge some other people, so intead of saying "that's me, accept me the way I am, and do not ask me to justify", well, we do find ways to justify!

Then I also talked about the fact we have 2 guts, and that it is not so easy to change your biome when it has moved location from colon to upper gut. And maintaining something that works is different from repairing something that has to work anyway, and ha chosen different pathways to be as efficient as possible though not optimal.

Then yes our gut and heart are said to have enough nerves so that we can ask them when they feel, apart from using our cortex brain to analyse what is going on. We do not ask this brain because we have difficulties to understand its language, which has been called the felt-sense. Actually, we still use it without noticing, and it gives us our spontaneous likings, our intuitions, our preferences, even the direction we take for wok and hobbies.

Then, I have enough informations that cannot be put in a post, that the limbic brain has not ove-ridden the autonomic nervous system. We even know that our 3 brains are like russian dolls, and that each older brain will be preemptive to the newer ones. That is why limbic or emotions are preemptive to the cortex. And the reptile brain is not that selfish, or else the word selfishness has 2 meanings, and I think we use it often in 2 different ways. There is a positive aspect and a one we do not like, when it means hurting others for our sake. But this is what happens when people get into panick, and this is as spontaneous as heart beating and it will override the rest, much to our shame when we come out of this highly sympathetically activated state! As we have different levels of trigger point among human beings, according to many factors, this explain we have difficulties in understanding that some people cannot do what we can do with a little effort. But we NEED this automatism because it is life-saving in most cases, and also because this brain is what makes everything work inside us.

Then a nice see-saw movement between sympathetic and para-sympathetic is what allows to have activity and get up in  the morning with enough energy, and then enter a relaxed state in hammock without staying in the activation we think we will need the day after! We can go down only when we know we will have the strength to go up again, and this called resilience. When you think about your last day of work and about the next day of work, instead of relaxing at home, then you have a problem with the nice waves of your system....

Not enough para-sympathetic = no rest and digest state, but also no good immune system! And this is enough to change your gut biome. Sorry no reference under my hand for all this, but I assure you I have.

So we actually have one stomach, and then intestines, both large and small, that are actually subdivided into several different parts of the system based on how they differ in how and what they do. But we have one gastrointestinal tract.

The fact that there are nerves in our hearts and gastrointestinal tracts doesn't convey upon them a semi-sentient quality unto themselves. It might make more sense that our subconscious minds might be communicating with the telepathic hive intellect of our individual internal microbiome, but I say that in absence of any evidence whatsoever.

What I was saying about the "reptile brain" refers to hardwired survival instincts that tend to favour the individual over its progeny. It is a theory that the emotional phenomenon of love may have been responsible for overriding this reptile brain focus that favours the individual to instead sacrifice the well-being of the individual so that the offspring might survive.

I don't understand why it is that we should treat our gastrointestinal system as two separate organs. Why not three? Is the appendix not significant enough as a repository for gut bacteria that it shouldn't be in on the conversation?

As to the Greeks, you're referring to their development of debate, which led to sophistry, which was exactly what you're talking about, the goal being to win the argument, and not to assess an argument on its merits. But I think it's a long stretch to say that because the history of reason contains the concept of sophistry, that all intellectual endeavours are then tainted.

Which is not to say that some aren't. But it doesn't follow logically that because there are some black sheep, all sheep are therefore black.

The power of the para-sympathetic system over the body is statistically seen in cases of psychosomatic cures and illnesses, as well as the placebo effect. I don't think the phenomena are by any means exhaustively understood. I have also read recently that, statistically speaking, people facing serious illness that have a stimulus for that type of para-sympathetic or psychosomatic activity, either from an inner vitality or drive, or due to external factors like belonging to a religious or spiritual community, or some other factors that gave them reason to think positively, have statistically higher survival rates (or longer duration of overall survival).

I don't pretend to understand, but it makes sense to me that if you get 20% better just by taking a pill you believe will make you better, even though it's just a sugar pill and it's your belief, or positive thinking, that's responsible for the improvement, the mental and physiological framework is there that might be used to do more, or to do specific things.

But I think, and this might just be me, that things go off the rails a bit if we start anthropomorphising aspects of our physiology. My heart and my gastrointestinal system and my brain are all me. Based on the logic of the placebo effect, I can't see any benefit to identifying one's internal organs as other than one's self.

-CK

When we digest food, we are depending on the gut microbiome.  Those guys digest many things we cannot digest with our own enzymes.  And who is there today in what numbers depends on what we've been eating in the recent past.  How long it takes the microbiome to adapt to changes in our diet is aobut a month.

It occurs to me that when I was growing up, I often saw my mom chew up food we were eating that the baby couldn't manage and little bits of chewed up food in the baby's mouth for it to eat.  When I had kids I found myself doing the same thing.  I assume this is a widespread, time tested behavior, probably world wide.  

I wonder if this is a method of inoculating a baby's gut with some of my gut biota?  I assume there is some movement of microorganisms in my body.  

Also, every one of my kids ate a fair amount of dirt, grass, small insects, etc. when they got a little older and I put them on the grass to crawl around.  Also probably inoculating their little guts.

r ranson wrote:
10. Foods of my ancestors are changing.  Milk and wheat of today are very different than they were 150 years ago.  Plant breeding and other ways of changing the wheat plant, combined with new ways of growing wheat, and cooking wheat without fermenting it first are all new to our culture.  Could this be more related to why we cannot digest wheat than the possibility that our gut hasn't changed since pre-agriculture times?

Why am I thinking about this?   We have two people in the home with gut illnesses.  We're having trouble absorbing the required nutrients through our food alone and are seeking a diet that will heal our gut.  Challange is, the reasoning behind that diet needs to make sense to me.  Saying that human digestion hasn't changed in 10,000 years contradicts what I know of evolution from other sources.  So I'm curious if there is some mechanism there that makes humans exempt from natural forces, if my previous understanding of how this all works is wrong, or if something else is going on.  

Like I said, very disjointed thoughts.  But my instinct tells me they are related somehow.  

I'm not finished with the thread yet, so forgive me if this is a repeat..
I believe the food changes are much more of an impact. 100 years ago harvesting wheat was done mostly by hand. There's a family friend who has a threshing machine built in 1919. (it's epic let me tell ya!) But the point being that the rest of the process was done the same as it's been done since humans farmed grains at all. Cut, shock up, teepee shocks together. Let dry and finish ripening. Haul shocks to place/building for threshing and winnowing. Store away for future. It takes time. The grain has it's own little aging and developing period. I can't recall specifics.
Today! Hooo-boy! You got acres being cut and threshed in moments. Hauled off the field in hours. Sent through a grain dryer in hours. Stored within a day or two.

Add to that.. The plants of our early ancestors hadn't traveled much. They developed in sections of a continent and that's where they were. This was the soil of that region. This was the minerals it was high or low in.
These days a lot of selection has been done on grains without knowing what else has just been selected against. All the grains are selected for the right height for the harvesting equipment. Maybe the taller wheat had the genes that were more pest tolerant.. more drought/wet tolerant.. Any number of things that the natural wild and early cultivation wheat population may have had.

Add to that yet more.. These days we have herbicides, pesticides, fungicides that not only aren't doing the job they proclaim, but also bind up nutrients in the soil. All these nutrients are not only being washed away with bad management.. But what is still there is all locked away because of the 'cides' so you have a more and more 'sterile' base to grow from. Now you don't have soil with the building blocks a plant needs, you have a base that you try to force plants to grow in and spoon feed them nutrients. I believe Joel Salatin and several others talk about the nutritional content of food just not being up to par of what it was a hundred years ago. A big part of that is selective breeding plants to death and growing in soils that do not have any nutrition available to plants to grow nutritious food.

r ranson wrote:

Todd Parr wrote:

Everything I have read suggests that 10,000 years is more likely, although I agree 100 years ago our diet was better.  This article is good overview of human evolution.

 http://www.beyondveg.com/nicholson-w/hb/hb-interview1c.shtml

Sorry I'm on my phone and can't put the link in correctly.  The article talks about just how much our health decreased between the end of the Paleolithic era and the beginning of the Neolithic.  We lost 4 inches in height among the changes. In general, evolutionary change takes millions of years, not hundreds.  

This is really neat.

My brain translates that article to say "a little after 10,000 years ago, our diet changed suddenly and the health of the new people on that diet suddenly went down for several generations".  I hope this is right.

Tell me, has our health gotten better since then?

A few years ago I went down this research rabbit hole of teeth and feet. The modern diet was introduced to native peoples and everyone went from healthy to frequently ill and horrible teeth. Modern shoes were introduced and while you're less likely to be cut or jabbed by a lot of things, it brought bad habits of standing, walking, running and overall poorer stature and bone development. The teeth stuff was amazing! Ya you live on stone ground grains, especially the stones that also grind down quicker, then the wear on teeth is bad. But the teeth are healthy. The shape of the mouth and teeth placement is good. Bad teeth was found in the rich or deformities like cleft pallet which are not genetic.
I can certainly tell you I cant think of anyone I know in person who doesn't have some sort of dental problem. Myself included.

I've not read everything in this long thread, so pardon any redundancies.

I am trained in anthropology and have taught Intro to Physical Anthro, and I follow developments in the field, so perhaps can make a useful comment.

There seems to be a general misunderstanding about the time frame of evolution, and about whether Homo sapiens is continuing to evolve in the modern world.

Evolution can occur quickly in a small population. And it can occur quickly in response to any environmental factor which causes a high death rate. An example would Europeans who have a resistance to plague, since nearly everyone without such resistance died, while those remaining had resistant genes, which therefore quite quickly became quite common in the population. The same dynamic applies to Native Americans who nowadays don't die off from exposure to measles or the common cold as they did when the Spanish and other Europeans first arrived to expose them for the first time to those diseases.

In today's world we are exposed to a lot of industrially-produced toxins. It is not known exactly which ones are doing what, but if it is true, which is likely, that some of them are causing problems which affect reproductive viability in any way, then evolution is occurring. Keep in mind that evolution is defined as "a change in allele frequencies in a population over time". As with plague or measles, some people are more resistant to the negative effects of toxins, processed food, etc., than others, and so their alleles will tend to increase while those of susceptible people increase at a lower rate.

Naturally this is difficult to study in real time given the relatively long period in humans between birth and reproductive viability. With garden plants, land races, etc., that period is only a year or less, except with some perennials such as fruit trees.

The research on the evolutionary effects of industrial products and processed foods has scarcely been done at all, in part since the corporations producing those things are not prone to funding such research, for obvious reasons.

Regarding food, an interesting mutation occurred in the steppes, among Indoeuropean speakers, a few millennia ago, which enabled the digestion of unprocessed lactose. This lactose tolerance was spread quickly in Eurasia, especially to Europe, since it gave an obvious advantage to those who could glean the maximum nutritional benefit from consuming milk. No analogous mutation regarding industrial products is yet known.

In my limited experience as a nurse, I have seen numerous adaptations.  On a pretty regular basis babies enter the world with both male and female sex organs.  I saw a child with 2 noses.  Society does not approve of such things.  In the cases I am aware of, surgical corrections were made.

To take my limited experience and running with it.  I suspect a male with 2 noses might be shunned by a female with one nose, but a female with 2 noses might be attracted to him.  My suspicion is that we, as a species, are seriously intervening with our adaption process.

Of course, it could be argued that our intervention is also part of that process.