NOTE: PaleoFX is coming up quickly and my talk will be related to some of the issues discussed below. It’s going to be a fun meeting. If you’d like to attent, buy a ticket or try your luck in FastPaleo’s PaleoFX ticket giveaway.
Marlene Zuk is an evolutionary biologist at the University of Minnesota, and her Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live is an important milestone for the Paleo movement: professional evolutionary biologists and anthropologists are now responding to Paleo ideas.
I haven’t yet read Paleofantasy but I have read:
- Zuk’s 2009 piece in the New York Times, The Evolutionary Search for Our Perfect Past.
- The excerpt in the Chronicle of Higher Education, Misguided Nostalgia for Our Paleo Past.
- A number of reviews including John Hawks’s review in Nature (see also his blog post), Cordelia Fine’s in the Wall Street Journal, and Laura Miller’s review in Salon.
Of the reviews, John Hawks in Nature is the most useful. Most Paleo community members have taken the term “Paleofantasy” as an attack upon the Paleo diet and lifestyle – as an assertion that our views conflict with reality – but Hawks suggests another take:
Zuk’s use of the term ‘fantasy’ is just an emphatic way of describing the hypothesis-forming that is essential to evolutionary science. We play with hypotheses, explore their predictions and try very hard to falsify them. So it is, in a way, unremarkable that so many hypotheses proposed by anthropologists about ancient environments now seem to be wrong — and, in a few cases, even ridiculous. [1]
The title “Paleofantasy” may sell more books than “Paleohypothesis,” but the latter is undoubtedly more accurate. The Paleo movement is based on a scientific hypothesis, and exploring its validity is a very reasonable thing for an evolutionary biologist to do. The ancestral health community should be flattered, not offended, that its science is being engaged by other scholars.
The Paleo Hypothesis
What is the Paleo hypothesis? The original version was expounded by Melvin Konner, Boyd Eaton, and others in the 1980s and 1990s. Here is Melvin Konner’s (2001) summary:
One approach, applied by Eaton and colleagues since the mid-1980s, is to consider the environment of evolutionary adaptedness for our species and to view it as the shaper of the latest draft of our genome…. This approach leads us to the discordance hypothesis, which attempts to assess the disjunction between those environments and the ones we live in now … [S]everal important chronic degenerative diseases have been interpreted as “diseases of civilization” because they appear to result from this disjunction. [2]
I’ve bolded the key ideas: that humans have an “environment of evolutionary adaptedness” approximately represented by the Paleolithic, and that multiple diseases result from a discordance between the modern and Paleolithic environments.
To operationalize the Paleo hypothesis, one must identify a modern implementation of the Paleolithic diet and lifestyle – not necessarily a complete re-enactment, but mimickry in essential elements. The most influential operationalization was created by Loren Cordain in The Paleo Diet (2002) and subsequent popularizers such as Robb Wolf tracked his diet closely. Their advice can be found on Cordain’s “What to Eat” and Wolf’s “What is the Paleo Diet?” pages: eat meat, fish, eggs, nuts, fruit, and vegetables; eschew starches, dairy, and some other foods.
A Target-Rich Environment
Both the Paleo hypothesis and its popular operationalization are vulnerable to challenge.
Most vulnerable is the operationalization by Cordain. It consists of an odd mix of foods. The meats, in accordance with archaeological evidence, derive mostly from grassland herbivores, while the plant foods – nuts, fruits, and vegetables – come largely from forest plants – trees. It is almost as if the evolutionary picture was that humans are chimps who learned to hunt, and our ancestors would dwell in the forest like chimps when foraging for plants but commute to grasslands to hunt animals.
This view drives Paleo toward a low-carb diet, since modern domesticated fruits and vegetables generally have only 50 to 200 carb calories per pound, and Paleolithic fruits and vegetables had even less. It would not have been easy for Paleolithic hominids to gather and eat many pounds of forest plant foods per person per day – especially when bipeds are not suited for getting fruit and nuts out of trees, and much of the band would have been hunting animals in a sparsely-treed semi-open grassland!
Not surprisingly, anthropological evidence has found that Paleolithic diets were quite different from the meat, fruit, and vegetables diet. There is little doubt that in the Paleolithic, starchy plants were a more important source of carbohydrates than fruits, just as they are among modern hunter-gatherers.
What is interesting about Zuk’s work is that she takes on the theoretical part of Paleo – the hypothesis of modern discordance with an environment of evolutionary adaptedness. Many in the Paleo movement take this as foundational, so if it were rebutted then one might think it would call into question the whole ancestral health movement.
Zuk’s Critique of the Paleo Hypothesis
Zuk’s critique strikes me as sound but disappointingly unambitious.
The Chronicle excerpt focuses on the persistence of evolutionary change:
[I]t is easy to assume that evolution requires eons. That assumption makes us feel that humans, who have gone from savanna to asphalt in a mere few thousand years, must be caught out by the pace of modern life …
[D]iscoveries like [the timing of the development of lactase persistence] make it clear that we cannot assume that evolution has stopped for humans, or that it can take place only ploddingly, with tiny steps over hundreds of thousands of years. In just the last few years we have added the ability to function at high altitudes and resistance to malaria to the list of rapidly evolved human characteristics …
Gregory Cochran and Henry Harpending even suggest that human evolution as a whole has, on the contrary, accelerated over the last several thousand years …
In one way Zuk is understating her point. Human genetic change did accelerate significantly over the last 10,000 years, due to rising populations which introduce new mutations to the human genome more frequently [3], and due to changes in selection pressure resulting from the establishment of large-scale societies following the domestication of animals.
Yet in another respect she is exaggerating it. The time required for favorable mutations to spread through the human population hasn’t shortened much since the Paleolithic. Even the most strongly selected recent mutations, such as that for lactase persistence, have spread only partially through the world’s peoples. There has certainly been insufficient time for the rest of the genome to evolve to an equilibrium with recently introduced mutations.
Yet, in the Paleolithic, the ancestral diet was probably similar in general outline for at least 2 million years: it consisted largely of meat, marrow, and plant foods collected from open woodlands and tree-spotted grasslands. There was sufficient time for new mutations to appear and rise to fixation, and then new mutations to appear and reach fixation against this new genetic background, and so on for many cycles. It is certainly possible that humanity became adapted to this (slowly changing) Paleolithic diet, and that the genetic variety introduced in the Holocene has been insufficient to destroy our fitness for a diet like that of the Paleolithic, and insufficient to make us well adapted to new Neolithic diets.
This point – that the relevant time-scale for assessing adaptedness may be the time for the genome to reach equilibrium, not merely the time for new point mutations to appear and grow to regional prominence – is an elementary one in evolutionary biology, one that is made in our book on pages 4-6, but from the Chronicle excerpt and various reviews (including this Amazon reader review), it appears that Zuk does not acknowledge this reason why treating the Paleolithic as an environment of evolutionary adaptedness may be a “Paleoinsight,” not a “Paleofantasy.”
Nor is it necessarily the case that adaptedness to the modern environment is assured by rapid recent evolution. To illustrate my point: a diet of Twinkies and Coca-Cola could never be healthful, and could never become our optimal diet, no matter how many billions of years we spent adapting to it. It simply lacks the nutrients needed to support sophisticated life.
So Zuk’s major points – that evolution has been a process of continuous change, never reaching a stable equilibrium; and that Paleolithic environments were diverse, making it difficult to specify an environment of evolutionary adaptedness or establish modern discordance with it – do establish that the Paleo hypothesis is not automatically trustworthy and needs to be supported in any given application by specific evidence. But she did not prove that it is never useful. It may guide us to a better diet and lifestyle.
Entertaining, But Unambitious
From reader reviews, the verdict emerges that Zuk wrote an entertaining book, using “Paleofantasies” as hooks on which to hang interesting facts, observations, and insights from evolutionary biology.
But most Paleo readers seem to have wanted a more ambitious undertaking. Most Paleo reviewers seem to agree with Theodore Roosevelt, who taught that in science
It is not the critic who counts … The credit belongs to the man who … strives valiantly, who errs and comes up short again and again, … who spends himself for a worthy cause; who, at the best, knows, in the end, the triumph of high achievement, and who, at the worst, if he fails, at least he fails while daring greatly … (“Citizenship in a Republic,” speech at the Sorbonne, Paris, April 23, 1910)
Evolutionary biology has much to teach us about how we should eat and live for best health. It would be good for evolutionary biologists to spend themselves for the worthy cause of identifying those truths.
What Does the Paleolithic Tell Us About Our Optimal Diet?
Coincidentally I came across a TEDx talk on Paleo diets by archaeologist Christina Warinner that makes a creditable effort at providing an alternative operationalization of a “Paleo diet.” Ignore the first three minutes in which she calls Paleo a fad diet based on meat; the latter part of the talk is excellent.
She makes the excellent point that domesticated plants have been bred for reduced toxicity. We may now be able to eat a much healthier diet than was possible during the Paleolithic, thanks to reduced-toxicity plant foods.
Warinner suggests the following modern operationalization of the “Paleolithic diet”:
- Eat a diet high in species diversity. Do not, as Americans do, concentrate plant consumption among a mere three species: corn, soy, and wheat.
- Eat fresh foods. Stored food loses nutrients and spoils; preservatives that inhibit microbial growth may disturb our gut microbiome.
- Eat whole natural foods; avoid refined processed foods. Natural foods have a full package of nutrition and healthful fiber. We should not indulge our new-found ability to consume sugar far more rapidly than would have been possible in the Paleolithic.
These are all points we make in Perfect Health Diet:
- The benefits of diets high in species diversity are discussed in chapter 24 – because “the dose makes the poison,” diverse diets prevent toxins from becoming poisons.
- The benefits of eating “recently living plants and animals” rather than processed foods constructed of purified nutrients are discussed in chapters 2, 8, and 23.
Warinner’s three recommendations are an excellent start toward a healthy diet. It’s good to see a scholar venturing to make prescriptive suggestions.
Yet I think that evolutionary biology can tell us much more than this. To see what it teaches, we have to broaden our perspective beyond the Paleolithic and the original “Paleo hypothesis,” and venture into biology.
Maybe “Paleo” Should Stand For Paleozoic Diet
One of the novel insights of Perfect Health Diet is that the evolutionary roots of the optimal human diet are ancient – they extend back to the start of the Paleozoic Era 541 million years ago when a great flourishing of multicellular life took place.
The rise of multicellular life depended on the use of carbohydrates to glycosylate membrane proteins and to form a carbohydrate-rich extracellular matrix to support multicellular structures. This increased use of carbohydrate was the last major change in the macronutrient composition of life. As life feeds on life, it represented the last major change in food.
In Perfect Health Diet, we discuss a number of evolutionary patterns determined by evolutionary selection and indicative of our optimal diet:
- Until bodily protein is depleted, all animals tolerate fasting quite well. This is because the composition of the body closely resembles the composition of our optimal food, so that self-cannibalization is nourishing.
- Breast milk has a similar composition in all mammalian species. This is because all mammalian species – whether herbivore, carnivore, or omnivore – need the same nourishment.
- Evolution doesn’t modify the body’s composition in order to exploit a new environmental niche, but rather modifies the digestive tract’s ability to transform novel foods into the desired nutrient mix. Herbivores, carnivores, and omnivores have similar nutritional needs and similar bodies; only their digestive tracts differ. The digestive tract is evolutionarily “plastic” in a way the rest of the body is not.
- In humans, the brain’s food reward system is an important guide to our most healthful diet. As dominant hunters and skillful foragers, ancestral humans had their choice of foods. Mankind’s Paleolithic evolution developed a food reward system that helps us choose an optimal mix of foods, and that brought us a diet that required minimal transformation by the digestive tract, enabling digestive organs to shrink. This is Aiello and Wheeler’s “expensive tissue hypothesis” [4], re-interpreted.
From this perspective, the optimal human diet was determined 541 million years ago, at the start of the Paleozoic, when the composition of animal flesh was more or less fixed. From that point forward, it was evolutionarily inevitable that as soon as a creature became able to “rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground” (Genesis 1:26), so that the whole world became its buffet table, this creature would lose its expensive digestive tract and gain a brain capable of guiding it to a healthful pattern of eating.
Our optimal diet is deeply constrained by our biology; it does not vary in any environment. Environmental changes that bring a new dietary niche force evolutionary changes to our food reward system and our digestive tracts, but they do not change the optimal human diet – one that, like breast milk, is little altered by evolutionary change. Because our body composition is evolutionarily stable, the mechanisms by which we select our foods and transform imperfect diets into something better are changed; not the mix of nutrients we need.
I like the name “Ancestral health movement” better than “Paleo” because it is less specific about whether there was a specific time of evolutionary adaptedness, or when that was. In truth, different organs of the body reached evolutionary adaptedness at different times – some as far back as 541 million years ago.
But from another perspective, “Paleo” is quite fitting. The Perfect Health Diet is truly “Paleo” – in the sense of Paleozoic, not Paleolithic.
Conclusion
The Ancestral Health Society is forming a new scholarly journal, The Journal of Evolution and Health, to complement its annual Symposium.
It is coming at a good time: when scholars have begun to appreciate the significance of the Paleo/Primal/PHD/Ancestral movement, yet remain unfamiliar with its recent scientific and intellectual developments.
Yes, the scientific hypotheses on which “Paleo” began were flawed (though insightful and scientifically productive); but a newer and better scientific foundation has been developed.
The Ancestral health movement has become popular because it works: it truly does heal and prevent disease, and millions have experienced its benefits. So it is no fad diet, and will not fade away.
I hope that scholars like Zuk and Warinner will continue their engagement with the ancestral health movement, and help us refine the science still more.
References
[1] Hawks J. Evolutionary biology: Twisting the tale of human evolution. Nature. 2013;495(7440):172 – 172.
[2] Konner M. Evolution and our environment: will we adapt? West J Med. 2001 May;174(5):360-1. http://pmid.us/11342525/.
[3] Hawks J, Wang ET, Cochran GM, Harpending HC, Moyzis RK. Recent acceleration of human adaptive evolution. Proc Natl Acad Sci U S A. 2007 Dec 26;104(52):20753-8. http://pmid.us/18087044.
[4] Aiello LC, Wheeler P. The expensive tissue hypothesis: the brain and the digestive system in human and primate evolution. Current Anthropology 1995 Apr;36(2):199–211.
via this link:
I’m surprised by how much I agree with Christina Warinner’s take on the paleo diet. It seems like it has become popular lately to “debunk” the idea that we need to eat like paleolithic people… and if all you’re looking at is Cordain’s Paleo Diet book it’s not hard to do. Even if we as a community are not really focused on “paleo” as much as we are on “ancestral health”, it’s videos like this that force us to question our beliefs and grow as a community.
I was glad to see it. She seems a talented scholar. I hope she’ll look deeper into the issues.
Hi Richard, when you talk about our bodies never been able to adapt to particular foods such as coca cola you are essentially talking about development constraints theory. Many evolutionary biologists, such as Stephen Gould, that this is at least as important in the evolutionary process as natural selection. Unfortunately, many people believe natural selection = evolution and that is simply not true. Other factors can cause evolution such as genetic drift. Anyway back to developmental constraints. The theory dictates that an organism is constrained by it’s biological past. for example an elephant is never going to become a flying animal because the biological changes during development that would be required to reverse those trends would be impossible to achieve. To use an even more extreme example humans will never evolve eyes in our feet, simply because our brain, visual cortex, and eyes are fixed in our heads and no matter how much natural selection goes on, it has to work on the fact that the eyes are in our heads. So for diet we are most certainly constrained into certain foods that will be healthy for us. Our bodies require certain substances to run (vitamins, minerals) these can only be achieved by certain foods = developmental constraints.
This paleo fantasy idea is great, and I am glad it has been discussed now. Back in the day Gould and Lewontin wrote a landmark study on how to approach studies in evolution titled ‘The Spandrals of San Marco’. Basically they argue that too many researchers, at the time, were coming up with ‘just so’ stories. Attributing functionality to evolution. Similar to saying we eat spinach therefore we are evolved to eat spinach. In other words because an animal or its physiology behaves in a particular way that means that it must have evolved for that purpose and this is simply not true! Evolutionary biologists such as myself take great care not to overstep the mark in this area. I study fish and am very careful not to say that fish was evolved to be in a specific habitat just because it is found there. Same goes for humans and our diet. Unfortunately, this is the biggest problem with the paleo diet and its followers. Everyday I see people coming up with ‘just so’ stories, or fantasising about what may have happened in the past. The fact is unless we have actual evidence to guide that ‘fantasy’ (i.e tool marks on the bones of fossils indicates we ate them) we cannot make these claims. It irks me daily, and you have no idea how much!!!!!!!!!!!
Great article I am glad this is been discussed.
Hi Dan,
I think I’d distinguish between developmental constraints and “reality constraints”. An organism’s evolution is constrained by its biological past, but this doesn’t change which endpoints are feasible, it only means that some are more accessible and can be reached quickly, while others are more distant and would require a more convoluted series of evolutionary changes to bring about.
Reality constraints actually limit what endpoints can be reached, even if billions of years and arbitrary environments were available for the evolutionary process.
I agree with your points – we do need biological nutrients like vitamins whose source is biological foods.
Best, Paul
When I talk about developmental constraints I am talking about the developmental constraints theory already established in evolutionary biology. What you are talking about when you term ‘reality constraints’ is in face developmental constraints theory. And a big part of that is about how certain endpoints cannot be reached (hence the term). In other words we are not lumps of clay that natural selection can mold into whatever it likes.
I will give you an example of a ‘just so’ story purely for dramatic effect. So American-Indians in North America were known to eat the maple from trees. They knew how to get it out, it was abundant, and it was able to be stored for long periods of time. They even taught the colonialists how to consume it. So my ‘just so’ story is we are clearly evolved to eat sugar. These people ate it in abundance, didn’t have any delitirous effects, and continued to thrive. So based of current paleo diet logic how can one argue that sugar is bad for us? it WAS eaten by hunter gatherers in their natural diet. There is no basis to say that a hunter gatherer diet should be low carb or even sugar should be avoided based off the current paleolithic approach to eating. There may be current scientific studies which show that sugar is bad, but that isn’t a paleo approach.
I think we focus too much on what we shoudn’t eat and not enough on what we should. The fact is hunter gatherers, and our ancestors, would make use of just about any foods available including honey, maple etc. Pretty much the one constant is that they all predominantly ate nutrient dense foods and this may have included some shit stuff too. Our bodies need certain foods to get those nutrients we need and I feel we should be focusing our efforts on the similarities between HG groups in the types of food they ate (ie what types of foods are nutrient dense) and stop pissing our pants because someone chose to eat some salt, dairy or sugar. I mean I just had 300g of spinach, fresh shrimp, onion, courgettes, carrots, mushrooms but I added salt and some rice. Now how gives a crap about the rice the fact is my body just got a bit hit of nutrients!
Agreed! Identifying a healthy mix of foods is the goal of our book.
It’s not hard to find examples of HG peoples eating toxic staple plants that shortened their lives because nothing else was available. Bracken root (stomach cancer) in New Zealand and other places is a good example; peanuts and (I have read in a nutrition textbook) some bananas (which contain catecholamines when green) are others.
I liked Warinner’s point that domestication and breeding for taste has also removed a lot of toxins.
So has the application of exogenous pesticides in some cases, e.g. celery.
Isn’t it the quantities in which we are eating sugar that is the problem? HFCS is a recent development, and it’s in everything processed (or some other form is). I tolerate sugar very well…in small amounts, by way of fruit or the occasional ice cream or other dessert. The average American eating a processed foods diet is getting bombarded constantly, not to mention the high glycemic effect of grains. Maybe the colonials ate a lot of maple sugar when it was available and then went months without it….or they sold or traded a lot of it. But I doubt they were eating it all day every day.
I was ill and laid up in bed a couple of years ago and read the Little House on the Prairie series back to back. What shocked me was in the earliest books sugar was only available when Pa took his annual (bi-annual?) trips to town and usually had to wrestle wolves and swim torrential rivers to get it to them. Or there was some kind of maple syrup tapping party that sounded brilliant fun.
By the last books it seemed like they ate very little else but sugar. And Laura (author) seemed obsessed by it.
I was saddened by not surprised to read (on Wikipedia!) that she and quite a few members of her family developed diabetes.
Thanks, Lorna. I read the first book but had no idea they became sugar addicts.
Oops sorry for the huge wall of text. I would love to discuss this with you further as I think its important to change a lot of peoples approach to paleoin terms of the way they think about evolution, and you and your blog are a good platform for it. I put in the wrong link so you can contact me now as I just updated my details on your blog.
As Paul J says in his commentary, Christina ends up re-affirming the major tenets of PHD, and of the current thinking in paleo – a wide range of fresh, real, minimally processed foods. Now, we optimise it a but further by cutting out problem foods like grains and most legumes – which eliminates here three big ones – wheat, corn, soy.
I am getting a bit tired of people assuming paleo is a re-enactment, and then criticising it accordingly.
It is framework, to see what we can learn from the past, to help us in the present. That this approach ends up at the same place she does – fresh, whole, minimally processed foods, shows that it has merit.
It is a search for a healthy way of eating, and while it can no doubt be improved upon further, it is miles ahead of the Standard American Diet – that is the one that should be the target of all this criticism.
This is a great piece, Paul. I addressed the very topic in my last blog post, looking at the highlights in Miller’s Salon review. I’ll state here, as I did in my post, that Zuk seems to (1) misunderstand the AH movement and (2) misunderstand the nature of Neolithic evolution. I attempt to discontruct Zuk’s claim that the Neolithic is “plenty of time” to evolve. Your point about achieving genetical equilibrium is crucial to that cause.
Nice post Kevin. Link: http://www.hackingevolution.com/2013/03/deconstructing-paleofantasy-by-marlene.html
Oh, and I also sent Zuk and Warinner each a friendly message with a link here, suggesting interest in a response. We shall see! 🙂
When talking about successful ancestors, are there height or bone density standards for that? I always thought that really tall, big people would get tired from all that joint pressure. But I’ve read a couple times that polynesians used to produce lots of 7 ft tall people. I’m Samoan. If I eat better, do you suppose I could grow a giant or two for progeny? 🙂
What I mean is, how can I know if someone is talking about ancestors that were strong and healthy, as opposed to puny?
Unrelated, I thought I read somewhere on your blog that Kitavans don’t utilize Vitamin C. If read correctly, could it be astaxanthin that is used instead?
Hi Crystie,
I haven’t heard those 7 foot Samoan stories. Unless you and your husband are tall, I’m guessing it’s unlikely!
We have a lot of ancient skeletons, so we have a pretty good idea that Paleolithic peoples were strong and healthy. They were about contemporary sizes, 5’10” for men and 5’3″ for women.
I don’t think we’ve ever written about Kitavans and vitamin C.
Hi Paul,
I meant I may have read the comment about Kitavans and vitamin C in a comment section.
Darn, I’m only 5’6″.
While a lot of us are sitting back and watching the paleo movement implode, you are doing a good job of keeping on target. Stick to the basics and minimize the use of the word ‘paleo’ and you’ll be just fine.
I feel like your work expands on two of my favorite ‘gurus’: Jack Lalanne and Westin A. Price…they both focused on real, nutritious food and hardly ever mentioned carb-protein-fat.
It’s when people try to pin down a one-size-fits-all macronutrient ratio and eating style that everything falls apart.
Excellently written, wide ranging piece here. Really great! My only question/gripe is one with the larger paleo scene: I have yet to see anyone review or comment on Jared Diamond’s book: The Third Chimpanzee. If someone did and I missed it, my apologies. I was particularly fascinated by his assertion that Hunter Gatherers were not big time carnivores and mostly focused on small game and vegetables. Thoughts? Cheers and keep up the great work?
Hi Jake,
Paleolithic hunter-gatherers aren’t thought to have focused on small game until the period approaching the Last Glacial Maximum when food was scarce, and many small-game technologies (snares, nets, traps) had been developed. Bone assemblages are mostly large animals until 35,000 years ago and small animals really become significant around 20,000 years ago. That’s a very small part of the Paleolithic. And this is in Europe, in the tropics large animals were still available.
Paul: Excellent post. In 2013,we are better able to measure biomarkers to get an understanding of how we process what we eat. Biology trumps Paleofantasy every day.
Jack Lalanne was a very low fat advocate who consumed a large soy isolate shake everyday. In his early career he was more whole food, but in later days moved to a high veggie, fruit intake, tons of vitamins, and very little fat in his diet.
While he should be lauded for his message it was far from perfect; and his longevity might be genetic as his brother lived to 90.
Paul Jaminet wrote: “So Zuk’s major points – that evolution has been a process of continuous change, never reaching a stable equilibrium; and that Paleolithic environments were diverse, making it difficult to specify an environment of evolutionary adaptedness or establish modern discordance with it – do establish that the Paleo hypothesis is not automatically trustworthy and needs to be supported in any given application by specific evidence.”
Who of consequence in the Paleo/ancestral health community wasn’t already aware these points? Who is she arguing against? Loren Cordain was mentioned, but I doubt that he would disagree with any of these points and you obviously don’t. She seems to be criticizing straw men. Her critique would have been useful if she had wrote what you wrote, but she didn’t.
There are a lot of “straw man” arguments in many of the critiques. It seems that many outsiders feel they don’t need to take the time to delve deeply into the ancestral health literature. Maybe we haven’t made that literature accessible enough to them, or maybe they underestimate our sophistication.
It’s looking like Zuk would have benefited greatly from spending a little time to read just a few of your blog articles. Critiques can be helpful, but it seems like she did far less delving than other critics of ancestral health who made some better and more timely points (albeit less politely than Zuk), like Sally Fallon, Anthony Colpo and Matt Stone.
For example, Fallon made the pro-dairy case over a decade ago and plenty of folks in the movement already added dairy foods to the Paleo 1.0 approach before Zuk came along. While dairy is still controversial, at this point it’s old news.
[Pardon the grammar error in my first comment: “if she had wrote” should have been “if she had written”]
However, I’ll try to take your approach and look for something positive we can take from this. She did raise the rapid evolution point, which I knew years ago that the critics would eventually get around to, and it gave you and others the opportunity to write excellent refutations of it that I enjoyed. Thanks for that. It’s a topic that does deserve more delving into and I think it actually makes a good case FOR an evolutionary diet and lifestyle approach rather than against it.
Paul, how our dna (or even our “epigenetic”) could have “adapted” or “evolved” to eating grains when eating grains in fact has granted more offsprings and no deaths before reproduction age? From a species point of view, grains are great! From a post reproductive age individual health, fatal!
Thanks for your terrific work.
Hi Jose,
I think there have been evolutionary adaptations to help us cope with grain toxins, and the presence of these adaptations may be one reason why Europeans are less prone to metabolic diseases than aboriginal peoples who adopt modern diets.
Thanks for your answer Paul. I keep not seeing which is the evolutionary pressure for adaptation given the fact that eating grains doesn’t kill anyone before reproductive age and it even facilitates feeding more children. I cannot see how, some random mutation that allows better toleration as we age to eating grains could have been selected.
You’re misunderstanding how evolution works, which is unfortunately all too common in the Paleo movement. “Because evolution” is quickly beocming a tool of pseudoscience.
In this case, humans that are better adapted to eating grains would remain more healthy while eating them, thus providing a selection pressure over those who weren’t adapted to eat grains.
In other words, if I’m eating grains and handling them fine,and you’re eating them and you get IBS, I’ll probably have more children over the long term.
And as a healthier parent or later, grandparent, you’ll do a better job raising them and gaining and passing on knowledge. That is a huge survival advantage.
Hi Paul:
I get the sense from Warriner and Zuk that legumes may not be so bad. Any further thoughts on this?
Hi Steve,
They’re probably not that bad with traditional methods of preparation (long soaking, thorough cooking in boiling water). Few people (or industrial food companies) prepare them that way today.
“I haven’t yet read Paleofantasy but I have read:
Zuk’s 2009 piece in the New York Times, The Evolutionary Search for Our Perfect Past.
The excerpt in the Chronicle of Higher Education, Misguided Nostalgia for Our Paleo Past.
A number of reviews including John Hawks’s review in Nature (see also his blog post), Cordelia Fine’s in the Wall Street Journal, and Laura Miller’s review in Salon.”
Maybe you should read the damn book before writing a post based on the book you haven’t read!!
Charles, presumably Zuk’s views are fairly represented by her other writing on the same subject, which Paul has read, if not then she’s not much of a writer. It would be nice to review the book too, but her views are out there, assuming she’s not into self-contradiction for publicity purposes.
Paul is not reviewing the book but riffing on what this kind of attention potentially means for the former Paleo Re-enactment Society, now known as the Ancestral Health Movement, and re-stating core principles in a new way, which is always a good move in any blog.
Great post Paul and raises a couple of ideas:
1) If our ancestors ever fancied eating forest foods, they would have had to fight the stronger, highly territorial and better-armed forest apes for them. There’s an evocative phrase of Robert Ardrey’s – “Tuskless in paradise”.
2) Blake Donaldson and Richard Mackarness got excellent results with a Flintstones version of a “Stone Age Diet” in the 1950s, so pandering to the modernizing impulses of scientists may not be all that important for medical purposes.
Thanks George. Good point about competition from forest apes – until very recently forest apes were highly evolutionarily successful in their niche. Thanks for the Blake Donaldson and Richard Mackarness reference, I hadn’t heard of them.
Dr. Blake Donaldson’s views on diet were reportedly inspired by Vilhjalmur Stefansson’s The Friendly Arctic (1921). Donaldson later influenced Dr. Alfred Pennington.
Great thoughts- it’s very nice to see this is article is already being spread amongst the Paleosphere. The idea that life and humans isn’t as simple as paleo people might envision it shouldn’t be shocking to anyone. Paleo and the resulting implications to modern life is a great theory and should be explored. It would be foolish to not use this as a starting point for exploration. That being said, nothing is absolute or set in stone and we will never have it figured all out, the universe and humans are too dynamic. We should welcome criticism and attention. The best way for the ancestral movement to achieve a critical mass is to be tested, hardened and prove its worth. Thank you for keeping an open mind and continuing to spearhead the ancestral health community.
Evolution –
lactase persistence and extra amylase genes are examples of the expansion of pre-existing genes, and presumably relatively easy adaptations.
As far as adapting to modern diets, the target shifts every few generations. Look at fats; our early industrialised ancestors needed to adapt to low-PUFA diets due to the reliance on stored flour and fat. Then they needed to adapt to diets high in trans-fats, then since the 70’s, to diets high in omega-6 linoleate or low-fat diets. Recently they need to adapt to high-MUFA diets, who knows what is next.
The modern diet is in a constant state of flux with new toxins and unusual configurations of nutrients appearing at regular intervals.
There’s a link to Blake Donaldson’s book Strong Medicine here:
http://babel.hathitrust.org/cgi/pt?id=mdp.39015003228171
A quote from Strong Medicine (1962)
“Food was the primary concern of man as he evolved, and it had to be
right. He lived on the fattest meat he could kill and on water. In those
million years every weakling who could not maintain perfect health on
that food was bred out. If he could not leap six feet straight up in the air
to catch the branch of a tree, some sabre-toothed tiger was likely to solve
all his problems. The ability to live well on meat and water is the
inheritance of mankind.”
Boggles the mind why you didn’t read the book. 🙄 🙄 🙄
I haven’t had time to read it yet. I think for what I wanted to say here, the information in reviews and excerpts was enough.
Great post. You guys are the forefront of paleo/ancestral health and it is refreshing.
“Ancestral” sounds good to me, maybe it’s time for a name change to distinguish the diet…
She seemed to demonize high meat intakes though. She kinda seemed anti fat and pro-tons-of-fibre. I would say the abundance-of-fibre-for-gut-health myth has been taken care of by Kresser.
High protein intakes probably are not entirely healthy, and Paleolithic diets may have been on the high side of optimal meat intake. Anti-fat is a mistake. The fiber picture is a bit complex, there’s mixed evidence, but there’s no doubt Paleolithic diets were fiber-rich compared to modern diets. So she is plausibly 2-for-3 on those.
Good call. Why you so smart?
Hmm. Whats your thoughts on being able to adapt to high protein intakes, if given enough time?
http://www.ncbi.nlm.nih.gov/pubmed/10578207
I wish I knew more about this stuff so I could talk about it intelligently. Maybe one day after I graduate I’ll have time to look into it deeper.
That’s an interesting paper, thanks. When you use more muscle it grows and when you use more kidney it grows too, apparently. I think the negative effects of a high protein diet will usually require many decades to see, eg shortened lifespan, http://www.ncbi.nlm.nih.gov/pubmed/23454735. The exception would be gut dysbiosis leading to excess amine production.
Actually I am on the Paleo diet. I bought this one just 2 months ago.
http://cooklikeacaveman.com/paleo-cookbook-review/
It works for me, I mean I have never even imagined the results that I have experienced over the past few months. Everything else is better as well, I think this works for me. Although some people might brush off the idea, but everything is different for everybody.
I watched the Ted talk by Christina Warriner. It contributed a little to our understanding of what our ancestors ate, but not much. Interesting points about today’s common vegatables.
What puzzled me was her statement that humans have no adaptations for eating meat. Compared to chimps and other apes, we have smaller teeth, jaws, chewing muslces, and smaller hind guts. Aren’t these considered adaptations away from leaf eating and towards meat eating? When compared to a lion, sure, it doesn’t look like we are adapted to eating meat. But why on earth would she compare us to lions, instead of our closer, more recent relatives, such as apes? She also apparently doesn’t realize that “fad paleo diet” crowd encourages consumption of organs and marrow. She never does come to a suggested importance of animals in our diet, on a useful, percentage basis. That would have been nice.
Hi Macoda,
I think the more significant point is that cooking and stone tools change the game. If you’re using tools rather than teeth to shred carcasses, pounding meat to tenderize it, and cooking it to render it more digestible, we shouldn’t expect our teeth to look like those of a hypercarnivore.
Actually we are meant to have stronger jaws than most people have to day. We have gone from a diet of though food to a diet of soft food. As a result we don’t work our jaw muscles as much. Paleo man also used his jaws as a tool, e.g. chewing leather. Just look at ancient skulls and teeth from the paleolithic area. The teeth all show extensive wear unlike most peoples teeth today. The teeth all show a flat surface from alot of use.
Yes, but stronger jaws and tooth morphology are two different things. She was referring to teeth shape. Our teeth are better at grinding than tearing.
Paul your right. I was too quick to comment and misunderstood what was beeing discussed. My bad. Also thanks for clarifying your thoughts on Warinner’s presentation.
Of course we don’t because we’re *omnivores*. We’re made to eat plants and animals. Also, as Paul said, tools give us some room for crappier jaws.
Thank you Paul! That was an excellent overview of the value of an ancestral approach to health. I also agree that engagement by other scientists in this movement is a good thing. Exciting really. There is so much to be learnt about disease and physical and mental health from this approach.
Thanks for the great article Paul. A question for you, how do we apply this point
“Eat fresh foods. Stored food loses nutrients and spoils”
to tubers like potatoes & yams which are routinely stored for long periods? Can we assume that for these foods “properly stored” is as good as “fresh”?
Hi Mike,
I do think properly handled and stored potatoes and yams are functionally about as good as fresh, but I wouldn’t say that supermarket potatoes are necessarily well handled. However, if you peel them and discard any discolored flesh, they should be good.
Hi Paul,
Chris Kresser says for those that dont like the taste of beef liver, they can cut raw liver into small pellets, freeze them for two weeks, then swallow them like pills. He says two weeks of frezing should kill any pathogens.
My question is they are raw, so is raw liver safe? Or could there by pathogens still existing after two weeks that might be better killed by cooking?
Hi David,
If you’re doing that, I would only freeze the interior part of the liver, not the surface, which is where most of the microbes are.
Also, I wouldn’t eat pork liver this way, as it’s too likely to be infected with viruses.
Freezing is effective at killing protozoa and parasites but I don’t think it is effective at killing viruses. So cooked would be better.
Hi Paul,
What’s the timeframe for The Journal of Evolution and Health in terms of its release, opening for submissions etc?
May have a paper or two in the works for submission 😉
Thanks
James
Hi James,
Get started writing!
The software system will be up and running sometime in April; at that point we can accept submissions.
We aim to publish quarterly and bring out the first issue in Summer, preferably by AHS, but it depends on our ability to attract papers. We’ll probably publish incrementally online, so if your paper is done earlier it can appear before then. It is an open-access journal, no page fees.
If you want editorial feedback on your paper ideas, email me and I’ll see if we can choose an appropriate editor for you.
Hi Paul,
Excellent stuff. I’ll be working on a paper in tandem with preparing my AHS presentation along with hoping to begin some collaborative research with a local zoo maybe later in the year.
I’ll be sure to drop an email regarding feedback when they are more complete.
Is there a list of editors for the journal yet?
Thanks
James
Doing most of the work will be Aaron Blaisdell, David Pendergrass, and myself. There will be a long list of associate editors in the various disciplines we cover.
Would you like to serve in an editorial role? It is volunteer work, no pay and very little glory, but would be good for the community and good for developing connections and furthering an academic career.
Paul
I’d be very interested in being involved with the journal in some way.
I’ll drop you an email now so we can correspond regarding it.
Thanks
James
Paul writes that
In one important sense this strikes me as incorrect. Science, these days at least, puts great emphasis on peer review. And in peer review the reviewer or “critic” plays (or should play) a key role in improving the work of the valiantly striving author. Certainly, my experience of peer review is that critic’s comments have always improved the quality of my papers, sometimes massively.
Hi Rich,
I agree that peer review improves papers. Multiple perspectives are valuable.
I think what the Roosevelt quote, which I was attributing to the Paleo community, is implying that the person who doesn’t count is he who is only a critic, not a “man in the arena”.
I’m sure you saw that Mark Sisson posted a pretty harsh review of the work. From what he describes, it sounds like Zuk was just trying to cash in on the interest in ancestral health – and not really interested in contributing anything useful to the discussion (rarely do strawman arguments do that).
That’s too bad…
Hi Jim,
Yes, saw that. I thought Mark’s post was very good. I’m hoping Zuk will attempt to re-make her argument in a serious and scholarly way.
Sorry Paul, but I don’t think this woman deserves that much praise. She is misinforming people through what seems to me to be a lazy attempt of critiquing the paleo diet concept. Her presentation was not at all fair to the paleo community. She misinterprets and clearly show a lack of understanding for the basic concepts of a paleo diet, a diet which is supposed to be a modern version, not a factual representation of what our ancestors ate. How can you take a person seriously when she fails to even understand the basics of such a diet and then proceeds to debunk it. She gives several false or bold statements regarding human physiology and adaption to meat consumption, fat etc. She also goes on to talk about things like how our ancestors ate organ meats and marrow, which the paleo folks are clearly already advocating, so whats her point? She also basically seems to imply that humans were plant eaters for the most part. Again, evidence please? In my opininon she fails to debunk anything, which was suppose to be the topic of this presentation. Sure she has some valid points regarding bananas and brocoli, food diversity etc. But again the TOPIC for the presantation was to DEBUNK the paleo diet. None of the prominent paleo authors like Mike Sisson, Rob Wolf etc. is saying that our domesticated foods found at our grocery store or farmes market is necessarily the same version as what our ancestors ate. That doesn’t mean it is bad for us. What the paleo authors advocate is to eat from the same FOOD GROUPS as our ancestors and try to approach the same macronutrient range.
Btw. by “she” I mean Christina Warrinna.
Also, I forgot to say that when she is talking about how all these different fruits and veggies are different now from what they were in paleolithic times, she is basically weakening her own argument. This means that it would’ve been nearly impossible for our ancestors to gain enough calories and nutrition from an almost plant based diet, when the diet is high in tough fibrous, low nutrient dense plants and low in fat, like she implies that our ancestors diets were.
Mark Sisson, Robb Wolf and Christina Warriner*. Just had to correct it. Wrong 3 out of 3, haha. Should’t be that difficult. Maybe I should give the ketogenic PHD version a try (Brain infection PHD joke).
Hi Acai,
I basically agree with you. But I prefer to try to find and highlight the good points. Robb Wolf had a good post on Warinner’s talk which paralleled mine. She made a number of mistakes and clearly isn’t that familiar with the ancestral health movement, and seems to have a vegetarian bias, but there were some positive takeaways for us.
Her valid points are supportive of balanced ancestral natural whole foods diets, such as ours.
I thought it was intriguing that domestication and breeding of agricultural plants has probably made them healthier for us. I agree that does work against her vegetarian argument, but it also works against some of the Paleo re-enactment type arguments.
Hi Paul, great info as always!
Have you seen the recent interview with Marlene Zuk in slate magazine?
http://www.slate.com/articles/health_and_science/new_scientist/2013/04/marlene_zuk_s_paleofantasy_book_diets_and_exercise_based_on_ancient_humans.2.html )
On page 2 of that interview she makes the following statement:
“There has been lots of discussion of cancer as a modern scourge, but this isn’t supported by the data. It turns out that ancient remains show about the same incidence of cancer as we have, with the exception of lung cancer…”
The same incidence of cancer???
That sentence really shocked me, but I have yet to see it addressed in any discussion of the book that I’ve come across. Could you shed some light on this?
That is a good tip particularly to those fresh to
the blogosphere. Simple but very accurate info… Thank
you for sharing this one. A must read post!
Paul, I think it is hazardous to critique a book that one has not read oneself. You are relying on the analysis of other reviewers and that’s a dangerous game. In other areas some scientists’ ideas were rejected not based on the reading of their works but based on the reading of someone else reading someone else’s review of their work.
That said, I would love to read your review once you have read the book. I’m working through my copy right now.
One other point: I think it is also a mistake to talk about ancestors eating “meat” – in English that makes us think primarily of “muscle tissue”. The truth of the matter is that humans have been eating all kinds of animal parts, not just muscle tissue – the fat and the organs having been extremely important to the diet, and the blood as well. So whenever people describe traditional or historical human diets instead of “meat” they should use the term “animal products”
There’s certainly a great deal to know about this topic. I love all of the points you have made.
Acai Berry select has been featured in CNN. If you want to watch about it, you may do so here: http://youtu.be/mpZQC0hHvOg
I believe Acai Berry Select is legitimate. It has been featured in ABC News. http://youtu.be/ronBXn0AvGs
I wonder why the paleo diet advocates so seldom mention that hunter/gatherers typically get more of their protein from insects, grubs, worms, etc then from large game. The reason is pretty simple: insects, grubs, and worms don’t run away or fight back and you burn a lot less calories in finding them. I guess it doesn’t have quite the same romantic cachet as imagining our ancestors slaying mammoths… or else they just don’t want to eat bugs.
Hi Steve,
When they could, they got protein from large game, and there’s reason to believe they could for most of the Paleolithic, and that insects and grubs have been fallback foods for several million years. The reason is that protein was never the scarce nutrient, and insects and grubs are mostly protein.
Protein has always been a scarce nutrient for hunter/gatherers. Why would you assume insects/grubs as a “fallback”? I think you’re imposing a modern prejudice that would have made no sense at all to our ancestors. Insects/grubs are in many ways ideal food. They are nutritious, and if you’d ever spent time with hunter/gatherers (I have) you’d know they don’t taste half bad, once you get past the prejudice. More important, they can be caught by all members of the group with little risk and little energy expenditure. In the real world you don’t go out hunting a meal that can run away and potentially kill you when you can get a meal that sits still and doesn’t fight back. I suspect that you may have it backwards: whenever possible, our ancestors probably relied on that which they could get without risk: plants, insects, small animals like frogs, turtles, small reptiles and rodents or birds that could be caught in traps. Big game would have been the fallback, to be pursued in winter or drought when nothing else was available and need justified the risk. also when the game would have been weakened and vulnerable by the same winter or drought conditions that drove the need.
I disagree that protein was ever scarce except in famines. Insects are not an ideal food, they are 75% protein, and protein anywhere close to that level is toxic; Google rabbit starvation. I’m not saying they taste bad, I’m saying they cannot provide appropriate nutrition. They can avert starvation for a few months, that is what they are good for.
Anthropologists tell us that small animal hunting didn’t become a major source of energy until the Upper Paleolithic. It was large animals and gathered tubers before then.
Alright, I just want to address some of the arguments you have here, because they are fallacious. I am a student studying evolutionary biology, and it is pretty clear from your writing that maybe you don’t understand evolution very well.
1) Why would you link to a journal article that most people can’t access? That article written by John Hawks needs a subscription to Nature, which i have through my university, but most people wouldn’t be able to read it. That quote you pulled from the article saying, “it is unremarkable that so many hypotheses proposed by anthropologists about ancient environments now seem to be wrong” is extremely misleading because it is taken so out of context. You imply that the anthropologists in question are with the evolutionary biologists trying to debunk paleo diets when in fact Hawks is referring to the anthropologists who SUPPORT the paleo diets. Therefore, Hawks is saying the paleo diet hypotheses are ridiculous.
2) In “The Paleo Hypothesis” section, you imply that Melvin Konner and others came up with the paleo hypothesis and so support the paleo diet. They did no such thing. Walter Voegtlin the gastroenterologist was the one who started the paleo diet idea. Yes, Konner was arguing that there are certain characteristics we retain from millennia of human evolution that hasn’t evolved fast enough to modern environments. But this doesn’t apply to grains because paleolithic humans DID eat grains and legumes.
3) You state in your next section, A Target-Rich Environment, “…anthropological evidence has found that Paleolithic diets were quite different from the meat, fruit, and vegetables diet. There is little doubt that in the Paleolithic, starchy plants were a more important source of carbohydrates than fruits.” This is confusing because the sentence so clearly demonstrates you are aware paleolithic people ate starches and yet you advocate for a no-starch diet.
4) Your example of lactose tolerance is ill-informed. Lactose tolerance was never strongly selected for in human history. Having older children cease their ability to digest lactose has historically been a good thing because it would minimize sibling rivalry. If a 5 year old couldn’t drink his mother’s milk, then his 1 year old sister would benefit because she wouldn’t have to fight with her brother.
5) You write in the section “Zuk’s critique” that rates of evolution “haven’t shortened much since the paleolithic.” When you compare evolution in the span of thousands of years vs. in the span of millions of years, I think that’s a pretty dramatic shift. Even if only part of the human population has lactose tolerance, that’s still a pretty fast rate of evolution because it only took thousands of years, NOT millions!
6) It’s an “argument from ignorance” fallacy to say just because Zuk and other scientists can’t disprove the health benefits of the paleo diet, that it must be a better diet than those including grains.
There are so many holes in your logic I can’t address them all. But please educate yourself, starting by actually reading Paleofantasy, before you make these blog posts and spread misinformation.
Hi Xinci,
In reply:
1) What is wrong with citing journal articles that are not open access? Most scholars would consider it unethical to fail to cite one’s sources, whether they are open source or not. In this case, I made the point that the John Hawks review in Nature was the best I had read. Should he fail to receive credit for a fine review because Nature chose to keep his review behind their firewall?
You’ve also misunderstood Hawks, whose statement is a praise of fantasy, not a denigration of Paleo diets. Fantasy is a method of hypothesizing, which is a crucial part of science.
2) Although Wikipedia credits Voegtlin, I’ve never met anyone who read his book. The Konner-Eaton work on the other hand was extremely influential.
3) I have never advocated a no-starch diet; our diet is famous in the ancestral community for its abundant starches. You should visit http://perfecthealthdiet.com/the-diet/ to learn more.
4) Lactase persistence was non-existent at the beginning of the Holocene, first appeared in European ancestors about 8000 years ago, and was still extremely rare about 5000 years ago before the Indo-European expansion; but expanded to its present day prevalence of 35% globally with near-fixation in northern Europe. It’s almost the canonical example of strong selection. It’s been estimated the fitness advantage had to be on the order of 5%. That’s extraordinarily strong. … If you prefer academic sources, try this: “the estimated selection strengths required to explain the age/frequency distributions of −13910*T [36]—and of −14010*C [20]—are enormous (1.4–19 and 1–15%, respectively), which are among the highest estimated for any human genes in the last approximately 30 000 years [36,38].” (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3048992/) … The sibling rivalry idea may explain why lactase persistence didn’t begin earlier, but it can’t account for the rapid rise in prevalence of the persistent alleles.
5) You seem to be confused. You start by misquoting me; I didn’t say that rates of evolution haven’t shortened much (aside – rates don’t shorten or lengthen, they decelerate or accelerate), rather that “the time required for favorable mutations to spread through the human population hasn’t shortened much.” Selective pressures have changed with the rise of civilization, leading to strong selective pressures that weren’t present earlier; and population growth has increased the number of mutations appearing annually. These two factors have dramatically increased the rate of genomic change in the Holocene vs the Pleistocene. However, larger populations also mean that a positively selected gene has a lot more people to go through before it reaches fixation, which slows down time to fixation. It is the time to fixation that my statement was referring to. When alleles like the ones for lactase persistence have risen to near fixation in a few thousand years, it is partly due to strong selective pressures, but also the growth was aided by population replacement, as when the Indo-Europeans (we now know from sequencing of ancestral genomes) almost completely displaced the first Neolithic farmers from northern Europe. Of course population replacement is only effective at a regional level — there has never been population replacement on a global scale, therefore that mechanism only modestly shortens the “time required for favorable mutations to spread through the human population”, i.e. through all of humanity.
6) What? I said nothing of the kind. The argument for our diet is in our book.
It’s to your credit that you’ve begun to study evolutionary biology; but you should remember that scholarship is also a matter of character. Were you to bear greater charity toward those you read, you would find yourself learning more, faster. It’s impossible to understand those whom you approach with scorn; malice undermines the understanding. Seek first the kingdom of God, and insight will be yours as well.
Best, Paul
Paul, I absolutely adore your civility and charity, not to mention your very significant analytic skills. I have benefitted so enormously from the very great gift you and your wife have given to humanity. My health has greatly improved by using what I have learned from your teachings, and when I see this brilliant example of civility in response to incivility I am truly inspired to emulate your example in this realm also. Thanks you both from the bottom of my heart!
Wow. You could certainly learn a lot about humility and grace by reading more of Paul’s work.
Try not to be so arrogant as it will certainly backfire on you in due time (as it has in this comment, in my eyes).
The idea of a single consistent human “ancestral diet” is of course completely absurd: paleolithic diets would have varied dramatically according to location and season. The notion of a paleolithic diet depending primarily on meat from large herbivores is more a function of the mighty hunter fantasy than of any realistic assessment of paleolithic diets. Of course the residual evidence shows more remains from large herbivores, but that just demonstrates what we already know: that the evidence of eating large herbivores (large bones) is more likely to survive than the evidence of eating, say, insects, worms, grubs, and small amphibians and crustaceans. Like any hunter/gatherer, our ancestors would have had a strong preference for meals that didn’t run away or fight back.
The notion that dietary adaptation requires mutation is also highly questionable and inconsistent with observed reality. The ability of the human body to survive the multitude of fad diets inflicted upon it over the last few decades atands as evidence of what, again, we already knew: like most omnivores, we can readily adjust to a very wide range of foods.
Of course any diet, from vegan to paleo, that excludes processed foods is going to have a positive impact. The eccentricities of fads, though… well, one has to admit that they do make very good money for those who market them, but the consumer would do well to be skeptical. Just use common sense and keep it fresh, local, unprocessed, and diverse to the greatest possible extent, and don’t stress over the fad fights.
Hi Steve,
Actually, we actually have fairly compelling evidence that large game was an important part of the paleolithic diet — more evidence than just fossil remains of large herbivores with stone tool markings.
There are anatomical features in humans (and all fossils of genus Homo) which improve bipedal running — e.g. Achilles tendon, plantar arch, nuchal ligament, etc. — all of which are absent in earlier bipedal fossils (e.g. genus Australopithecus). All these running adaptations show up in the fossil record at roughly the same time as each other.
At the same time as these anatomical features show up in the fossil record, we also simultaneously see:
1. Enlarged cranial volume. Note that brains have a fairly hefty caloric cost, so this indicates the introduction of a new calorie source.
2. Smaller dentition, plus different microwear patterns on teeth indicating a shift from a plant-based diet to an omnivorous one.
3. Remains of large herbivores.
Note that:
* These running adaptations could not have evolved to help humans gather crustaceaens, etc.; as you point out, these do not run away, and so there is no selective pressure to develop running capabilities in order to catch them.
* These adaptations could not have evolved for the purpose of hunting large game unless large game formed a significant portion of the diet; otherwise the selective pressure simply would not have been high enough.
* Large herbivores are preferable to crustaceans — because large game provides a source of both fat and protein calories, while curstaceans and similar animals are almost purely protein. This is important because a majority-protein diet is lethal to humans, while a majority-fat diet is not.
Best,
Eric
Another interesting data point are the mass extinctions of large herbivores that occurred in the Middle East circa 500,000 BC, and Australia and the Americas with the arrival of humans 48 kya and 15 kya respectively; and the evolution of herd behavior in the large herbivores of Africa, protecting them from human predation.
Of course, once the large herbivores were extinct, the Paleolithic diet of necessity turned to other foods …
I see that the “post hoc ergo prompter hoc” fallacy remains common. It is unlikely that improved bipedal locomotion is an adaptation related to food acquisition, simply because it occurred over a wide area, and food acquisition strategies, and related demands, vary widely in different environments. More likely what we are seeing is an extended process of adaptation related to increasing reliance on tools, a common factor linking humans in multiple environments. As hands became more dextrous they also became more fragile, forcing full reliance on legs and feet for mobility. There were of course tradeoffs: bipeds suck at running (if we were adapting for pursuit we’d have gone back to 4 legs, like every other land animal adapted for speed), but the advantage of tool use outweighed them. You also fail to consider that food acquisition was by no means the only adaptive pressure early humans faced. Increased mobility would also benefit groups by allowing them to expand their foraging territory and compete more effectively with other human groups: again a factor consistent across multiple environments, which food acquisition strategy is not.
Similarly, the assumption that improved nutrition resulted in bigger brains could as easily work the other way around. Greater intelligence was a beneficial adaptation in multiple ways. People might not have become more physically adept, and may have become less so as more physical resources were directed to the brain, but the advantage of improved intelligence would more than compensate. There is no reason to assume that either of these adaptations was related to hunting large game… unless of course you really want to.
I didn’t mean to suggest reliance on crustaceans specifically, which would of course be silly. I’ve actually spent days with hunter-gatherers foraging along a stream. They came away with crans, shrimp, frogs, tadpoles, small fish, lizards, several birds caught in snares previously placed along the course of the stream, and quantities of edinble fern heads and tubers: a diverse an abundant day’s food acquired with minimal risk and caloric expenditure. Omnivore hunter-gatherers would by necessity be opportunistic feeders, focusing on whatever food source was easiest and most plentiful in any given location and season. If you looked at temperate zone hunter/gatherers, for example in the northern hemisphere, you’d probably find heavy reliable on large game in winter, when herds were weaker and less mobile and more easily acquired food was not available. Of course the archaeological record biases toward large game because those remains survive much more readily than the remains of smaller mammals, birds, amphibians, fish, reptiles, crustaceans, insects, grubs, etc.
The idea that dietary adaptation requires actuial mutation is also questionable: like most omnivores, humans adapt fairly readily to a pretty wide range of foods. Of course today’s processed non-foods are outside pretty much any adaptive range, and as I said earlier, and=y diet, from vegan to paleo, that excludes processed food is going to improve health, but many of the more arcane prescriptions seem pretty much irrational to me. I live now in a rural 3rd world indigenous community where the traditional diet leaned heavily toward rice, sweet potatoes, leafy greens, and legumes, supplemented by occasional meat. They did rather well with that.
Hi Steve,
Bipedalism was not the process of slow adaptation that you suggest. All our adaptations for bipedal walking (e.g. angle of the iliac blade, positioning of the foramen magnum, etc.) evolved in early members of genus Australopithecus. Then we see a string of fossils which are fully bipedal (legs and feet provide all mobility), with no substantial new bipedal adaptations showing up for around a million years — indicating that in genus Australopithecus, there was no selective pressure for running. Then all of a sudden, a bunch of adaptations to running (all of which are unnecessary for walking) evolve simultaneously, as I explained above.
Furthermore, bipeds emphatically do not suck at running; humans (in good shape) are perfectly capable of chasing down wild animals in the heat of the day. Obviously, our maximum speed is quite slow compared to other animals. However, bipedal running is very energetically efficient by comparison (in terms of number of calories burned per mile); in addition, humans have no hair, enabling sweating over the entire surface of our body. As a result, human runners have a level of endurance and heat tolerance which is exceptional compared to other animals. (For an amusing anecdote, see: http://www.bbc.com/news/world-africa-24953910)
Finally, a diet of rice, sweet potatoes, leafy greens, legumes, and meat… would be very healthy, provided that the legumes were prepared properly (e.g. traditionally-made Indian dal, as opposed to the way many people prepare legumes in America). Here is what Paul Jaminet recommends (http://perfecthealthdiet.com/the-diet/):
“We recommend… plant foods… including… rice, potatoes, sweet potatoes… low-calorie vegetables… including green leafy vegetables… One-half to one pound per day of meat or fish… Beans might be acceptable with suitable preparation.”
Best,
Eric
The story of the humans and the cheetah is a testament to human mental evolution, not human physical evolution. The humans in question developed and executed a strategy based on their knowledge of the cheetah’s strengths and vulnerability. They weren’t stronger or faster, they were smarter.
The notion of humans running down large herbivores seems to me sketchy at best. If we’d evolved to run down game, we’d be wolves. The core advantage of bipedalism is that it enables tool use… in any sense related to speed or endurance it is a disadvantage, not an advantage.
The evolutionary record is not the orderly process you make it out to be. There are large gaps, limited evidence, and abundant disagreements among experts over the interpretation of what evidence exists. Of course people trying to make one point or another can cherrypick evidence and interpretations that support that point, but that doesn’t make the point legitimate.
Common sense and observation of hunter-gatherers tell us that there would not have been any universal human “ancestral diet” or food-gathering strategy. Early human diets would have varied enormously according to location and season, and humans would have eaten whatever was available and easiest to get at any given time.
I just don’t see the point in fad diets, never did, never will. I was eating eggs, butter, and bacon when people said they were awful. I eat legumes and gluten today. Hell, I bake bread when I feel like it. Of course any diet that excludes processed food will make people feel better, but arbitrary or pseudoscience-based exclusion of one food or another or attempts to recreate some imaginary past diet seem to me pointless. There’s really no rocket science or hocus pocus to eating well and getting plenty of exercise… but I have to admit that the industry that has grown up around feeding the public appetite for diet and exercise pseudoscience is making one hell of a lot of money for people who choose to meet that demand!
Hi Steve,
The humans did not need specific knowledge about cheetahs. The same strategy (wait until it is really hot and keep pursuing the animal until it collapses from exhaustion) would work against pretty much any animal.
Humans look nothing like wolves for the same reason that killer whales look nothing like wolves: We (and killer whales) are predators existing in a different niche than wolves. Our niche was the ability to pursue prey at times of day when it was too hot for quadrupedal predators to do so.
Actually, bipedalism evolved before tool use, precisely because it is a more energetically efficient mode of transport than quadrupedalism. (Of course bipedalism limits maximum speed, which is why most animals are quadrupedal.) I shall not bother to explain the evidence for this claim, since you will simply accuse me of cherrypicking the evidence no matter what I say.
Best,
Eric