This blog is about the intersection between evolutionary biology and food. But also about practical applications, sustainable agriculture, and general tasty things.
In my last post, I wrote about how it's impossible for epigenetic changes from very cold environments 3-4 billion years ago to have been conserved. Somehow people thought I was accusing Dr. Kruse of making up cold-adapted monkey ancestors or something.
No, I realize he doesn't mention cold-adapted monkeys, but he also doesn't stick to bacteria living in sad cold slurries either. He also mentions ancient mammals. Dr. Kruse also has an interesting belief that all mammals “evolved in the polar environments on earth.”
I can't find any evidence that early eutherian mammals evolved in such an environment or even a later candidate for a polar eutherian that could be a possible ancestor. They discovered the earliest known (so far) eutherian fossil last year in China, Juramaia sinensis, in a Late Jurassic formation. The climate in the area at the time was relatively warm and dry. Juramaia sinensis' teeth suggests it was an insectivore. Many other early mammal fossils have been found in Asia, but as we know, mammals went on to colonize a variety of environments and climates.
Dr. Kruse says "mammals were ideally adapted for hibernation too, until they got too smart for their own genes sake.” It is indeed true that Juramaia sinensis and other early eutherians did hibernate. Mevolutionary biologists now consider the origin of biological changes distinct to hibernation behaviors to have originated even before the evolution of class mammalia and are displayed even in reptiles who live in very warm environments.
Why did most mammals stop hibernating then? As the excellent paper The Evolution of Endothermy and Its Diversity in Mammals and Birds says “ energy-optimization-related selection pressures, often dictated by the energetic costs of reproduction, apparently favored abandonment of the capacity for short- or long-term torpors." In most primates, it seems this abandonment was characterized by a species with a large brain and increased adaptability to a variety of foods and climates.
That's too bad, because hibernation (or even torpor, a less extreme form) would be very useful for things like organ transplantations, surgery recoveries, or long space flights. In the future, if we figure out how to do it, being able to trigger hibernation would be incredibly useful. Unforunately, the exact way to trigger hibernation is not currently known, though there are many promising candidates. Dr. Kruse however believes that the stimuli is already known: “the stimulus for hibernation in eutherian mammals and their descendants are tied to high dietary carbohydrate intake (proven fact already in science and not controversial).” If only it were that easy. A search of the scientific literature found no papers that posited that carbohydrate consumption triggers hibernation, though it is established that carbohydrate metabolism undergoes changes before and after hibernation. Scientists who propose triggering hibernation believe it would probably involve injection of chemicals produced by hibernating animals. This would be possible because many of the genes related to hibernation are still present in primates, not because we hibernate, but because they have other functions. We'd also have to figure out how to prevent brain damage, which has been a major challenge to such research since humans appear to suffer memory loss from brain changes normal to hibernating mammals.
Evolution is efficient and while genes that had interesting past uses (wouldn't it be cool if we could "reawaken" gills or the ability to lay eggs??) are often conserved in our genome, they are often expressed in radically different ways. It seems the areas that once encoded for gills, for example, are now related to the bones in the ear. As for those that don't seem to be in use now, as geneticist Paul Szauter says:
If genes are not expressed in the human genome, they do not survive intact over evolutionary time, because they accumulate mutations in the absence of selection. If there were squid genes in the human genome that could be "activated," it is likely that the accumulated mutations would result in a truncated gene product (3 of the 64 codons are "stop") with many changes in its sequence.
Dr. Kruse believes that humans, like all mammals, are optimized for hibernation and that remnants of mammalian hibernation are activated in humans based on certain times of the day: "It appears 12-3 AM are the critical hours at night are where the remnants of mammalian hibernation lies for our species". This is a far cry from the current state on literature related to hibernation. The idea that remnants of hibernation occur in humans at night also goes against the definition of hibernation. An excellent paper authored by another McEwen, Dr. Bruce McEwen, has a great concise definition "Hibernation is a highly regulated physiological response to adverse environmental conditions characterized by hypothermia and drastic reductions of metabolic rate"
Re-definition and special unique definitions of terms is another of Melia’s characteristics of bad books: “ The texts of these books all continue in the same excited first-person voice. They often introduce vague, undefined or invented terms.” A good example of this is in Dr. Kruse’s PaleoFX talk, where he references “ geothermal circadian cycles.” It sounds scientific, but there are no known circadian cycles that are tied to Earth’s internal heat* and it appears Dr. Kruse invented the concept since it is found nowhere else. It is a particularly deceptive practice, made easier by the fact that many of the terms that are often mis-used by these authors, such as the species concept or even hibernation, are the subject of some academic contention. But while academics might be arguing about whether or not bears are “true hibernators,” we can be assured that no one is considering that humans are hibernating every night because that doesn’t even fit into the realm of contention or the fringes of what is considered hibernation.
The only known primate that hibernates is Cheirogaleus medius, member of suborder Strepsirrhini, which diverged from the evolutionary line that led to humans over 70 million years ago. They also store a lot of fat beforehand, so I don't know if I'd like to hibernate like them anyway. I don't think I'd look so good and I probably wouldn't get much work done.
Even if it were conserved, Dr. Kruse makes the mistake of tying hibernation to extreme cold: “Cold environments are found as mammals hibernate in normal circadian biology…….this completely reverses IR in mammals and wakes them up when conditions are better for life.” Dr. Kruse’s cold therapy involves exposure to freezing temperatures, because he thinks that is linked to hibernation in humans. Kruses asks his readers if maybe diabetes has “become thought of as a neolithic disease in humans because we we have simultaneously lost the ability to hibernate because we evolved the ability to control our environment completely?” However, there are many animals that hibernate without exposure to very cold temperatures and biologists are still debating whether or not relative cold is even needed to trigger hibernation at all. For example, the only hibernating primate, the aforementioned Cheirogaleus medius, hibernates at 30 degree celsius (86 F). And if humans had lost the ability to hibernate because we control our environment, we would find the ability in related primates who do not control their environments. But we do not. The northernmost living non-human primate, Macaca fuscata, does not show any evidence of hibernation or even torpor, even those that do not visit hot springs. Interestingly, their winter diet does include digging for roots.
Why do so few primates hibernate? Around the equator, where primates evolved, seasons operate quite differently than they do in the arctic and other regions far from the equator. Because the environments and climates of Africa are so diverse, with many micro-climates in certain regions, most primates closely related to humans have evolved to be able to adapt to scarcity regardless of Earth’s axis tilt through the reliance on “fall back foods.” Possibly because of this evolutionary strategy, there is no particular dietary pattern that consistently characterizes the seasons for primates as an order or even within species.
Even in non-primates that live in the north, a very small percentage hibernate. For example, some squirrels hibernate, some don't. Those that don't often will cache food and eat it later. Some humans are known to raid rodent caches for carbohydrates. This contrasts with Dr. Kruse’s idea of seasonal biological changes being triggered by changing to carbohydrates or one season being devoid of carbohydrates: “it appears that dietary carbohydrates, which are only present in long light cycles in the summer in cold places, induce mammals to add PUFA’s to our cells to become fluid so we can function as we hibernate.”
According to Kruse, since carbohydrate consumption is tied to hibernation in cold environments, since we don’t really hibernate now (except sort-of, at night according to Kruse), carbohydrates might not be safe to consume: “Since we no longer hibernate……..maybe you need to consider how you eat carbohydrates within the circadian controls? Maybe what you thought was safe………really is not?” The implication is that carbohydrate consumption is only “safe” for mammals in the context of nature’s “design” for hibernation. In terms of our evolutionary line, that makes little sense. The vast majority of primate species consume diets of mainly carbohydrate, with two main digestive strategies. The evidence is that ancestors of modern hominins relied on a mainly-carbohydrate diet until somewhat recently.
If Dr. Kruse’s line of reasoning is true, most primates are living out of balance with nature and have been for millions of years. Some of his followers have said that this only applies if you live in the north since there are somehow some circadian controls only in the North that are tied to carbohydrates (zero evidence provided), but then the mice and squirrels who are eating stored or underground roots are violating natures law. And the idea that if you put an individual primate in the north that it will change its underlying biology to fit the north's light cycles does not have any evidence behind it (and in fact the fact that individual humans don't adapt particularly well to northern light cycles is perhaps behind the etiology of many modern illnesses).
As I will write in my next post, some human populations (and possibly other hominin lines) have genetic adaptations to more polar light cycles, but these are recent adaptations and are not shared by all humans. And one unique thing is that humans that inhabit cold regions have a raised metabolic rate during the coldest season, not a lowered one characteristic of torpor or hibernation, which suggests adaptations more similar to those found in wolves rather than ground squirrels**. Also, I must also discuss longevity being derived rather than ancestral. But I'll leave that to the next post.
* Geothermal according to the OED is “ 1. Geol. Relating to or resulting from the internal heat of the earth; (of a locality or region) having hot springs, geysers, fumaroles, etc., heated by underlying magma.””
** are non-hibernating squirrels naughty "nature's law" breakers? Particularly if they are eating stored carbohydrates?
In my last post on the subject of Dr. Jack Kruse, AKA, The Quilt, I briefly touched on the misuse of the ideas of quantum theory. Not long after, the WSJ had an excellent article on the mis-use of that subject.
Actually, it's pretty interesting because I agree that both the mis-use of evolutionary biology and quantum science aren't that bad, because they show that people really are interested in science. They are just suseptible to bad science, which isn't a surprise considering the abysmal state of scientific education in this country. Only about 4 in 10 Americans actually believe that evolution is a real thing.
Well, here is some background for new readers. My original post confused some people who do not post on Paleohacks, where my rivalry with Dr. Kruse has a very long history.
The question of what drives popular interest in such evolutionary fantasies is a difficult one. Frequently, they are bundled in with good advice, further increasing credibility among laymen. They contrast with legitimate evolutionary biology in that they contain simple and often epic “just so” narratives that appeal to people, in contrast with the complexities and fervent debates in the academic study of human evolution.
An example of one such internet popularizer is the aforementioned Dr. Jack Kruse, a Tennessee neurosurgeon and dentist who started plying a “paleo” diet and lifestyle program called the Leptin RX Reset on various popular paleo diet websites (particularly Mark’s Daily Apple, which is ranked 2000 on the Alexa web traffic rating system in the US, and Paleohacks, which is ranked 8000) in 2010. Calling himself “The Quilt,” his posts quickly became some of the most popular on these sites. In June of 2011, he launched his own website, containing a blog and his master “Quilt” manifesto and cracked Alexa’s top 100,000 sites in the US within months, hitting 26,581 in March 2012. He gained a further audience from the online Paleo Summit, where his talk was among the most popular and where many people learned about the next part of his Leptin RX Reset program, the Cold Thermogenesis Protocol (CT). Then he was a keynote speaker at PaleoFX, an Austin paleo conference sponsored by The Ancestral Health Society that drew many of the movement’s most popular speakers. In the fall of 2012, he will be a panelist on a debate about “safe starches” at the Ancestral Health Society’s main conference, the Ancestral Health Symposium.
Evolution is central to Dr. Kruse’s ideas and recommendations. In a comment to reader he explained “ Adapting evolutionary biology to what we learn makes us a better physician not matter what we do.” His writings contain many references to human evolutionary origins and how his readers can use them to improve their health in a modern context. Many of his readers have reported success from using his recommendations, but is the evolutionary basis behind them sound?
During a panel at PaleoFX in Austin Dr. Kruse said
Only humans who fail to listen to evolutions rule book of engagement die. You can eat a banana in the winter and feel fine but Mother Nature says it’s impossible………therefore we ought not to do it. I will follow her lead over a diet book guru or the opinions of a bunch of people who let their thoughts subjugate their genes. Feelings and thoughts do not trump neural biochemistry …
But his writings reveal a more ambivalent view of evolution. On one hand, on one blog post he says that “The speed of evolutionary change has far out stripped the ability of our paleolithic genes to catch up.#” But in his Quilt manifesto he outlines an extremely plastic view “A human is the only animal that can actually change its DNA just by thinking. Moreover, what we really think is just a biologic secretion. No different than any hormone released by the pituitary gland. Thinking is… well it is a meme that hijacks our brain’s chemistry. Any one thought can alter our genetic and biologic purpose in life.#” Therein lies an essential paradox- on one hand our genes are “paleolithic,” but on the other they are malleable simply by thinking differently. Perhaps it is just part of our genes that are “paleolithic.” For example, he refers to our brains being neolithic and able to “subjugate” our paleo genes, with negative consequences: "our neolithic brains allow us to make decisions that subjugate out paleolithic genes all too often.”
The idea that human genetics have not changed since the end of the Paleolithic roughly 10,000 years ago and that they are mismatched to the modern neolithic environment is a common one in paleo diet circles. Unfortunately, its origin can be traced back to academia and it lives on as a popular principle despite the fact that it has been the subject of considerable controversy in evolutionary biology. A common citation in paleo books is to An evolutionary perspective enhances understanding of human nutritional requirements, a paper written by Boyd Eaton, Melvin Konner, and Marjorie Shostak in 1996:
Geneticists believe that the increased human number and mobility associated with civilization have produced more, not less, inertia in the gene pool and that when the humans of 3000-10,000 years ago (depending on locality) began to take up agriculture, they were, in essence, the same biological organisms as humans are today (Neel 1994).
More recent research has come to the opposite conclusion, as newer statistical genetics models have actually found that human evolution has accelerated greatly in the past 40,000 years, certainly not freezing with the advent of agriculture. However, along with many other paleo authors, Dr. Kruse is still of the less dynamic mindset, writing that “Evolutionary pressures are selected for by the environments of our ancestors were exposed to and not for what we face today.”
n academic anthropology, new discoveries in archaeology and rapid advances in genetics have spawned a discipline in which textbooks are outdated as soon as they are published. Human origins are constantly under debate, which means that even if scientific education were adequate in the US, it is fairly hard for anyone to keep up. But even a basic outdated education on the topic would help a layman be critical of several pop-science fringe evolutionary theories that have cropped up, such as the “aquatic ape” theory. Why do such theories become popular? As anthropologist Jim Moore put it:
Even among scientists, as we've seen with Hoyle, there are times when assertions are put forth which are poorly drawn, yet, because they strike a chord, often of wishful thinking, they catch on and are repeated. Yet refuting them can be an exercise in futility. A good scientific review and critique is a lot of work, and takes a lot of time. But it's far easier to pop off with a theory that's poorly researched than it is to accurately go over all the things that the original theorist should've, and to provide a point by point refutation.
In the case of the Aquatic Ape theory, Jim Moore did a major service by creating a website to refute it, since as he elucidates there, there is very little incentive for academics to engage in debates with popular pseudoscientific theories, since they are so focused on doing their own original research for the benefit of their careers.
This is unfortunate, because pseudoscience has great power to shape the public’s consciousness. As anthropologist John Hawks puts it:
Is the Aquatic Ape Theory fairly described as pseudoscience? Every statement of natural causes is potentially scientific. What distinguishes science from pseudoscience is social. Pseudoscience is supported by assertions of authority, by rejection or ignorance of pertinent tests, by supporters who take on the trappings of scientific argument without accepting science's basic rules of refutation and replication. Pseudoscience is driven by charismatic personalities who do not answer direct questions. When held by those in power, like Lysenkoism, it destroys honest scientific inquiry. When held by a minority, it pleads persecution.
In a world where many people are unhappy and unhealthy despite our scientific advances, the idea that conventional science is wrong can be quite appealing. It allows people to buy into fringe pseudoscience for which little evidence exists and not question the lack of evidence.
Dr. Kruse has a new interesting spin on the "paleo" diet, though whether his approach is "paleolithic" is up for debate. His spin on the evolutionary approach lately has emphasized cold. Why?
Considering that 90% of the earth’s current biome lives in extreme conditions on our own planet today still, we might need to consider that what we think is “our normal environment” is not so normal for most of life on our planet or our evolutionary history. Life on Earth evolved in an environment much like we see on Titan today; in a deep ocean frozen solid at its surface with the capability of life buried deep with in it. The only escape was due to ejectants of water vapor from super heated water from underwater volcano’s. All these things are present today on Earth’s crust too. There is one major difference now between the two. We are warmer today than life began. There are others, but when one looks at Titan we see a frozen giant moon with a monsterous ocean beneath it.
This creates an issue of whether or not Dr. Kruse is even promoting a paleo diet or if instead he is promoting a Archean diet. But if he is referring to the Archean, it is mystifying that he emphasizes cold, considering that the Archean was probably warmer than today. Dr. Kruse has "references" on his blog, but I would challenge anyone to tie the meandering list on his blog post with any actual "facts" in his writing, like that cold promotes autophagy or that Neuropeptide Y is downregulated in cold weather.
Either way, debates as to the origin of life on Earth are still happening, with some (but not a consensus!) emphasizing the possibility that colder temperatures were the ideal place for single-celled life forms to originate. Dr. Kruse believes this is important because “life first adapted to extreme environments and then was naturally selected and adapted to a cyclic warming trend on our planets crust over time.” But he seems to believe that this adaptation was somehow incomplete: “Our hominid species may have adapted during this warming trend, but the DNA we inherited came from animals that were cold adapted.” Did DNA not adapt during this warming trend even through our hominin ancestors themselves adapted? It seems strange since Dr. Kruse believes that “One thought might just alter your DNA!”
Instead, he believes that these adaptations were mostly epigenetic, once again appealing to the idea that he knows more than conventional science “We know today that the power of epigenetics dictates a lot more about newer generations adaptations than we even knew ten years ago.” While epigenetics has become an important field, it is clear that a species adaptation to changing environments involves both epigenetic and genetic adaptations. Unfortunately, epigenetic is an appealing buzzword, which has been co-opted to absurdity. Dr. Kruse says that the warm paleoclimate that our primate ancestors were exposed to might not matter as much as we think it does because we might still carry an epigenetic imprint from the cold that engulfed Earth 3-4 billion years ago:
The modern science of epigenetics shows that who we came from and what they faced has a direct biologic effect upon subsequent generations DNA and phenotypes. It is crystal clear today, but the biologic implications remain unexplored in all modern day literature. What is happening on Titan maybe like opening up a blackhole back to a reality that used to be our own. The ability to see Earth at life’s evolutionary beginning.
This is confusing, because while here he blames epigenetic relics, in other writings he blames static genetics: “ The speed of evolutionary change has far out stripped the ability of our paleolithic genes to catch up. This mismatch causes major problems for modern humans.” Dr. Kruse seems to want to have it both ways.
The idea that epigenetic relics from billions of years ago are affecting us today is questionable, since the latest evidence shows that epigenetic changes are not stable enough to carry on from thirty generations and certainly not from 3-4 billion years ago. Evolutionary biologist Jerry Coyne has addressed people who hype up the evolutionary significance of epigenetics: “ There are a handful of examples showing that environmentally-induced changes can be passed from one generation to the next. In nearly all of these examples, the changes disappear after one or two generations, so they couldn’t effect permanent evolutionary change.“ This is in direct opposition to Dr. Kruse’s view of how evolution works:
I think evolution found that epigenetic modifications to be quite effective way to pass on environemental information to succeeding generations. So successful that it became a backbone law of genomic functioning. Evolution follows fractal patterning. So it is also highly conserved in all species. Today that appears to be true too.
While epigenetics has indeed led to important new understandings, it is less of a game-changer than Dr. Kruse presents: “Evolution uses epigenetics to determine adaptation to environments. We have discarded the strict definition of genetic determinism that came from Watson and Crick, as founders of DNA.” As evolutionary biologist Rama S. Singh succinctly put it:
While the new discoveries of the laws of developmental transformations are enriching our knowledge of the intricate relationship between genotype and phenotype, the findings of epigenetic inheritance do not challenge the basic tenets of the neo-Darwinian theory of evolution, as other than producing new variation no new processes of evolutionary change have been added to the ones we already know — mutation, migration, selection, and drift
Unfortunately, Dr. Kruse’s erroneous beliefs on human evolution have wide-ranging consequences holistically on his philosophy and recommendations, since it causes him to believe in conservation of many traits for which there is no evidence of conservation in Hominidae. Daniel F. Melia, professor of Celtic studies, recently wrote an article about characteristics of bad books that promote pseudoscience in his discipline. One of these characteristics is “Confident conclusions are often the result of chains of circumstance and supposition so long that even remembering their origin points while reading the books is difficult.” It’s easy to see that here and it shows how particularly ingenious this characteristic is since it makes anyone who tries to criticize the absurdities wade through the mire, further dis-incentivizing criticism.
A reasoning that Dr. Kruse uses for carbohydrate restriction is that epigenetics has sped up: “epigenetics has sped up and you eat a warm climate diet you by definition increase mitochondrial ROS that slowly kills you” A search of the scientific literature and academic databases found zero papers on epigenetics speeding up in modern humans. His article cites Wikipedia and himself.
The phenomena he blames on an epigenetic speed up also often do not have known epigenetic causes.
This is more fuel or proof that the “metabolic trap door” I found makes all starches less safe when they are eaten outside how our circadian biology accounts for them in our sped up systems. Evolution power laws has sped up too simultaneously to compound the issue. This explains why kids today are huge and bigger than their preceding genrations. It explains also why they reach puberty faster today.
Scientists are not sure what is causing earlier puberty(NYtimes article yesterday). If Dr. Kruse really knows, he should be eligible for a Nobel prize. It’s also interesting because paleo authors are often quick to point out that Paleolithic humans were bigger and stronger than modern humans because of their healthier diets and lifestyles. Yet Dr. Kruse is portraying this phenomenon as a bad thing, which begs the question as to why the paleolithic humans were bigger. Were they eating too many carbs? Why modern humans are catching up to paleolithic humans in terms of height is a matter of debate, but the best theory is it has to do with greater access to calories and less malnutrition stress.
Overall, on the issue of genetics and epigenetics, Dr. Kruse seems willing to rewrite definitions and build a pseudoscientific narrative that has little basis in reality. It shows that new scientific discoveries that become buzzwords in the public consciousness are very easy to manipulate in order to build such narratives. They make them sound scientific and cutting-edge, when in reality they are empty and devoid of factual basis.
I have MUCH more to write on this subject, including more on the evolution of mammals, hibernation, and hominin adaptations to cold. Also, a history of how he did not invent most of the regimens his followers praise so highly, as well as the actual non-pseudoscience evolutionary biology reasons that they work for those people.