Without further ado, it is with extreme excitement that I release my contribution to this discussion by way of an alternative hypothesis. It is currently in-press for the Journal of Applied Paleonthropological Hyperbole.

Abstract

The nature and causes of the disappearance of Neanderthals and their apparent replacement by modern humans are subjects of considerable debate. Many researchers have proposed biologically or technologically mediated dietary differences between the two groups as one of the fundamental causes of Neanderthal disappearance. Some scenarios have focused on the apparent lack of plant foods in Neanderthal diets. Here we report direct evidence for Neanderthal consumption of a variety of plant foods, in the form of phytoliths and starch grains recovered from dental calculus of Neanderthal skeletons. Some of the plants are typical of recent modern human diets, including legumes, and grass seeds (Triticeae), whereas others are known to be edible but are not heavily used today. Many of the grass seed starches showed damage that is a distinctive marker of cooking. Our results indicate that in both warm eastern Mediterranean and cold northwestern European climates, and across their latitudinal range, Neanderthals made use of the diverse plant foods available in their local environment and transformed them into more easily digestible foodstuffs in part through cooking them, suggesting that the extinction of Homo neanderthalensis may have been caused by introduction of food sources sufficiently deleterious to individual health.

The obvious question then becomes: How long do we have to wait before proclaiming Neanderthals were vegans? Why would Neanderthals continue to eat substances that were toxic?

For that, we need look no further than modern humans. When ingested items provide an observable short-term benefit in terms of calories, they are assumed to be beneficial. When the negative effects of toxic inputs are cumulative over a period of weeks, months, or years, individuals are incapable of isolating the confounding variables. This is further complicated by not being limited to dietary inputs, but also those of microbial, genetic, or other environmental factors such as shortages or overages of vitamins, minerals, and myriad chemical compounds. This problem has not been solved with modern scientific methods, and it is reasonable to assume that Neanderthals were less capable of determining cause and effect during the Pleistocene.

When the introduction of toxins does not manifest with sufficiently deleterious symptoms for a duration in excess of nine months in females, and nine seconds in males, significant adaptive pressure may not be placed on reproduction for that individual. Thus, the combination of an inability to disambiguate dietary toxins across a relevant period of time with the lack of strong selection pressure in delayed onset cumulative symptoms may result in both poor health and reproductive success, especially in the short-term. However, over time, the inability to recognize the delayed onset cumulative symptoms of the introduction of dietary toxins may lead to an increase in the consumption of the toxic sources. While a disconnect in the causal relationship between dietary input and its negative health outcomes persists, we may see a paradoxical increase in the consumption of such toxins which are believed to be beneficial. As consumption spreads through a population, the negative health consequences would come earlier in life, and with more frequency. Since we have no reason to assume adaptation in all cases (to the contrary, we must assume non-adaptation as the null hypothesis), it is possible that the paradoxical increase in consumption lead to unsustainable population levels within the species.

We are certain of two points: Neanderthals ate grains, and Neanderthals are extinct. To date, there is a complete lack of evidentiary support for hypotheses involving any benefits to the introduction of grains into the Neanderthal diet. Thus, we find all hypotheses of our colleagues that indicate grain consumption provided any survival or reproductive benefits to Neanderthals to be strange and unfounded. Since Homo neanderthalensis is extinct, and the deleterious effects of grain consumption can still be seen in the modern Homo lineage, it is more reasonable to conclude that increased consumption of grains in the Neanderthal diet played a role in their extinction.

Discussion

Grain consumption may result in death and subsequent fossilization of you and your species. Further research is required.

Acknowledgements

This research was funded by evolvify.com in connection with the upcoming book, ‘The Extinction Diet: How to Lose Weight and Save the Planet Through Individual Death and Species Extinction’.

I highly recommend investing an hour into watching this video. It’s a great archaeology/anthropology introduction for everyone interested in modern diets. It touches on a lot of the main concepts necessary to understand what the heck is being talked about when referencing the methods used to figure out what was going on during the paleolithic era. The talk is super-approachable for intro purposes, but Teresa Steele is also an actual scientist, so more advanced folks will probably appreciate some of what she discusses.

The Australopithecus afarensis to Agriculture Talk (3.4 million – 10,000 years ago)

One concept that seems obvious, but I’d never consciously considered is the size of animals eaten by humans vs. other primates. It’s easy to look at a timeline of the paleolithic and see that human ancestors ate some meat, but there’s a key distinction. Humans eat animals much larger than themselves, while all other primates eat animals much smaller than themselves. Thus, talking about primates as “meat eaters” is factually true, but it ignores a huge difference between Homo sapiens and other surviving species. Hunting large game necessitates a degree of cooperation that is on an entirely different level than the individuality of hunting small game. Since we know Homo neanderthalensis also hunted in groups, we can start to make some interesting comparisons with the rest of the Homo lineage.

“I’d like to add to that one of the things that’s unique about humans among primates is how much meat we consume. A large percentage of our calories come from meat on average – compared to other primates. Amongst primates, chimpanzees eat the most amount of meat. And humans on average eat about 10x the amount of meat as other primates.”

The interesting question professor Steele attempts to address in her research and in this talk is: “When did the differences in human and chimpanzee diets evolve?” The implications of this answer impact us in terms of social organization, evolved behavior, and optimal diets in the modern context. A big factor in determining this is that there is little evidence of hominin plant consumption during the Acheulean (~1.6 m – 100,000 years ago) period of the paleolithic. Admittedly, part of this is because plant evidence doesn’t fossilize as well as bones, but it’s interesting that the plant eating assumption persists on such small amounts of evidence. As usual, this refutes the vegetarian position in terms of evolutionary biology.

“Humans specialize in nutrient dense, hard to extract sources, while chimpanzees specialize in ripe fruits and plants that have low nutrient density which are also easily collected.”

The relative difficulty of resource extraction also carries implications for human society versus primates. This impacts the necessity of tool use and social organization to sustain expanding populations. Thomas Malthus’ famous prediction that human population would be restricted by a linear growth in the food supply compared to an exponential growth in population comes to mind. The Malthusian limit suffers from an assumption that humans are stuck in the chimpanzee mode of resource collection. To be fair to Malthus, it’s still possible that there is a limit on production that is simply beyond the date he predicted. Thus, the growth in production and population since his prediction doesn’t completely refute his hypothesis. The questions raised by Malthus remain at the foundations of geopolitical debates to this day.

Looking at this from the perspective of adaptive evolution, we also see foundations for hypotheses to explain the explosive growth in human brain size over the paleolithic. Dealing with the problems of tools and groups certainly placed different pressures on the evolution of humans. In other words, the information in this video underpins everything I write about on evolvify. Watch it. Love it.

Methods of study

1. Archaeological record (tools, artifacts, bones)
2. Skeletal morphology (bone mechanics & dental structure)
3. bone chemistry

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• Human Diet Unique in High Meat Content
• Australopithecus afarensis Diet
• Cut-Marked Bones 2.5 Million Years Ago
• Evidence of Ancient Hominids Eating Aquatic Animals
• Acheulean Hunting and Scavenging (Homo erectus)
• Exceptional Preservation Sites with Wood Spears
• Neandertals in Europe
• Bone Chemistry Findings
• Hunting Technology
• Middle Stone Age in Africa
• Modern Humans in Europe
• Plant Use
• Intensification of Resource Extraction
• Why Humans Replaced Neandertals
• Conclusive Evidence of Cut Marks
• Ratio of Fatty Acids in Diet and Brain Size

From a speciation standpoint, this wouldn’t be unprecedented. Whales evolved to their current iterations from land mammals. Though not a direct evolutionary ancestor, think about the modern hippo. They spend the bulk of their time in the water… even for mating. Interesting evolutionary side-note: Did you know whales have vestigial hips and legs embedded in their bodies… similar to our tailbones? Did you also know that whales are sometimes born with external legs through peculiar gene expressions?

As you watch the video, keep in mind that the hypothesis doesn’t say that we evolved from apes who had moved into aquatic areas and became fully adapted to aquatic life. It merely suggests that our ancestors spent a significant amount of time in the water for hundreds of thousands of years (guessing)… or just long enough to begin to develop adaptations for “a life aquatic”. Compelling evidence is our slightly webbed fingers and toes, and our ability to consciously override our breath control. The latter is key for diving and isn’t found in the majority of mammalian species. It’s also related to our ability to speak, a la voice control.

However, the mammalian dive reflex doesn’t really fit with the hypothesis. Since it’s found in nearly all mammals, there’s no reason to believe that the hominin line evolved it during the Paleolithic.

Did I mention this theory is almost universally ignored? Did I mention I don’t think there’s currently any compelling reason to believe it? Oh well, it’s interesting. It also attempts to explain some things that aren’t necessarily 100%  explained by the strict African savanna hunter-gatherer hypothesis. As such, I think it’s an interesting exercise in testing our assumptions…

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Edit: I was sent the following video via a friend on Twitter:

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Whatchya think?

Tools. [The End]

The folks whose eating habits are informed by evolutionary biology have all but subsumed the meaning of “paleo” in pop-culture. Since our minds begin to make associations at the mention of a word, this shift in meaning directly impacts how we think. Thus, for many people, the paleolithic era is mentally associated with hunters, gatherers, and grain hating. As one of them, that’s not a judgment, just an assumption that influences the rest of this piece.

For those steeped in the nuances of Pleistocene and Paleolithic research, please excuse me for a moment so we might indoctrinate any newbies: Pleistocene is a geological term which refers to the the planet and its physical properties across a particular period of time.  Paleolithic is an archaeological term that refers to humans (hominin, to be more accurate) across a particular period of time. Pleistocene and Paleolithic refer to roughly the same period of time, but they look at different things. Basically, the former looks at the world, the latter looks at the humans in it. That’s why Paleolithic is the term humans are most fond of. And… why we’ll drop Pleistocene for the rest of today. Paleolithic derives from the Greek: palaios, “old”; and lithos, “stone”. Thus, its etymological translation amounts to  “old age of the stone” or “Old Stone Age.” The reason stone is in there is because the material used to make the most advanced tools of the time was stone.

If the Paleolithic Era is archaeologically defined by hominid development of stone tools, how can we jettison the stone part and claim all tools are paleo? I prefer a different, but I think equally (if not more) accurate perspective. The psychologically important development in the Paleolithic wasn’t stone, but the tools. Surprise! …stone existed before the Paleolithic, but hominids didn’t make tools out of it, or anything else, really (and don’t try to derail the discussion by saying gravity was a tool, thank you very much). Stone didn’t change, our brains evolved to use it. That reveals the crux of my argument: the concept of tools is paleo. Now, that could rightly be passed off as linguistic trickery if we restricted “Paleolithic” to its archaeological roots. But as I mentioned above, we’ve expanded its use to encompass a period of human evolutionary biology and thus, by default, evolutionary psychology. It’s in the overlap of archaeology, evolutionary biology, and evolutionary psychology that the concept of tools gets significant in a major way.

A study by a team of archaeologists and anthropologists pinned down human brain size as a key factor that kept the hominid line in the stone tool making mindset for millions of years (Faisal 2010). That makes sense, and we know that brain size expanded significantly between the beginning of the paleolithic to its end. However, archaeology says nothing about the adaptive pressures required for evolutionary selection to effect such a change. To explain why our brains got bigger, we need to think about it from a different perspective.

From the standpoint of evolution, the development most important to humans in the Paleolithic was not the stone tools themselves, but the concept of tools. Across this period, humans developed what Marshal McLuhan would later refer to as “extensions of man”. Humans’ manipulation of their surroundings became the dominant strategy upon which evolution exerted its adaptive pressure. Human brains grew as man’s external manipulation abilities proved more efficient than biological “weapons”. We didn’t need to grow bigger, stronger, and faster than surrounding predators once this evolutionary cascade kicked into high gear. Further, once tool use becomes a strategy, it precludes (to varying degrees) biological evolution. McLuhan’s extensions become de facto solutions for the majority of adaptive problems. Every time something is used as a tool it serves as a proxy for evolution. Think surgical solutions to appendicitis, chemical solutions to infertility and impotence, condoms, guns, microwaves, refrigeration, tractors, et cetera, et cetera, ad infinitum.

Not only the tools themselves arise in the Paleolithic, but the psychological impulse to solve problems of survival and reproduction through the use of tools, arose during that time as well. Our brains were wired up for tools. So… what does this mean? If we look at this from the perspective of evolutionary psychology, our natural inclination to formulate tool strategies to solve problems is just as “paleo” as eating meats, fruits, and vegetables. This yields some paradoxical outcomes between the historicity of the paleo diet versus the pervasiveness of paleo psychology.

• Paleo diet enemy: Wheat (agriculture more generally) is, quite literally, a tool. The domestication of wheat was a human extension to solve problems of caloric inconsistency. Paradox!
• Industrial food processing is a tool.
• Chemical preservatives are tools.
• Corn-feeding animals is a tool.
• Alcohol is a tool! That’s right, people… Tools don’t have to serve an obviously adaptive purpose (though maybe we can pontificate on the reproductive “benefits” of alcohol related reproduction).

Not all tools are such anathemas to the health of humans. I make the illustration to open a space for questioning what is paleo in the historical sense versus what’s paleo in the sense of the shift of hominid conceptualization of tools. And obviously, some tools are amazingly beneficial.

• Is protein powder historically paleo? Not a chance. Is protein powder a tool that can be utilized for specific purposes?
• Is coconut oil historically paleo? Again, definitely not. And again… we use it as a tool.
• Are vitamin D supplements historically paleo? Until we find archaeological evidence of white lab coats in the paleolithic, it’s safe to say no. However, they serve a valid purpose as an absolutely beneficial tool for many modern humans.

So when we talk about paleo being a logical framework, and not a historical reenactment, these are the kind of questions we’re discussing. What historically “incorrect” or #notpaleo or #faileo tools that we have at our disposal should we be using? What are the costs and benefits associated with their use? In reference to paleolithic based diets, it makes sense to talk about the things we ingest, have injected into our veins, or absorb through our skin. That said, this logical framework can be extended to our physical activities, the way we design our lives, the spaces we choose to inhabit, how we interact with one another, and how we spend every moment. Since the question of the best way to optimize our lives is a ridiculously difficult undertaking spanning centuries of thought may be beyond the scope of this article, I’ll save it for the following three zillion posts [subscribe via RSS].

Our Paleolithic ancestors didn’t eat what they ate because they were nutrition experts. They didn’t do what they did because they possessed a superior level of philosophical knowledge or wisdom. [Perspective: speech as we know it didn’t exist for more than 2 million years (~85%) of the Paleolithic] Our ancestors simply did what they had to do with what they had available. They died when they did it wrong, and we are the benefactors of those who made the right decisions. We’re lying to ourselves if we think they wouldn’t have utilized many of the tools we have today… both nutritionally and otherwise. And that is a prime reason why romanticizing our Paleolithic progenitors and emulating a historical reenactment completely misses the important point of the Paleolithic. Look at everything that’s available and use the best tool at hand… That’s paleo logic in the modern world. And that’s still only half of the logic… next time…

References

Aldo Faisal, Dietrich Stout, Jan Apel, Bruce Bradley. The Manipulative Complexity of Lower Paleolithic Stone Toolmaking. PLoS ONE, 2010; 5 (11)

For context, I’ve also added some of the “great” moments in agricultural history. This is followed up by a chronological links of the major books related to the paleo diet and its aliases. I’m working on making this list more detailed and potentially adding a list of scholarly articles. It would be cool to be able to visualize the relative time periods as well. In a text list, it’s easy to lose perspective of how little time humans have been eating grains.

Pre-Homo Species

-6,000,000 Divergence from other ape species

-3,750,000 Australopithecus afarensis (staples: fruit, leaves, pith, seeds)

Paleolithic Era

-2,600,000 Lower Paleolithic (first stone tools)
-1,900,000 Homo rudolfensis (staples: leaves, seeds, tubers opportunistic: fruits, large insects, small vertebrates)
-1,900,000 Homo erectus (staples: fruit, meat opportunistic: small vertebrates, insects)
-1,830,000 Homo habilis (staples: fruit, leaves, herbs opportunistic: meat from large vertebrates)
-1,810,000 Homo georgicus (staples: tubers, roots, seeds, herbs, opportunistic: fruit, meat)
-1,600,000 Homo ergaster (staples: meat, small vertebrates, tubers, fruits, seeds, nuts, insects)
-700,000 Homo antecessor (staples: herbs, seeds, tubers, roots seasonal: nuts, fruits, mushrooms, meat)
-600,000 Homo rhodensiensis (80% plant sources, 20% animal sources)
-420,000 Homo pekinensis (staples: herbs, seeds, nuts, roots, tubers seasonal: meat, fruit, berries)
-400,000 Homo heidelbergensis (80% plant sources, 20% animal sources)
-250,000 Middle Paleolithic (stone scrapers, points, backed knives, etc.)
-200,000 Homo sapiens (modern human species)
-175,000 Homo neanderthalensis (staples: large game, bone marrow, cannibalism opportunistic: plants)
-40,000 Upper Paleolithic (musical instruments, blade tools, spear-throwers, bows and arrows)
-10,000 (BCE) End of Pleistocene

Neolithic Era

-9,500 (BCE) Earliest Agriculture
-8,800 (BCE) Earliest archaeological evidence of harvested emmer wheat
-7800 (BCE) Earliest archaeological evidence of harvested eikorn wheat
-7500 (BCE) Domestication of Maize/Corn
-7000 (BCE) Neolithic Agricultural Revolution (emmer wheat, einkorn wheat, barley, lentil, pea, chickpea, bitter vetch, flax)
-7000 (BCE) Humans breed durum (pasta) wheat by artificial selection of emmer wheat
-7000 (BCE) Average human height shrinks by 5 to 6″ (An Edible History of Humanity)

Paleolithic Era Part II: The Return

1975 – The Stone Age Diet by Walter L. Voegtlin

1989 – The Paleolithic Prescription by S. Boyd Eaton, Marjorie Shostak, and Melvin Konner

1995 – NeanderThin: A Caveman’s Guide to Nutrition by Ray Audette, Troy Gilchrist, and Alan S Brown

2002 – The Paleo Diet, Cordain

2005 – The Evolution Diet by Joseph Stephen Breese Morse

2005 – The Paleo Diet for Athletes By Loren Cordain and Joe Friel

2006 –  Evolution of the Human Diet: The Known, the Unknown, and the Unknowable by Peter S. Ungar

2009 – The Original Diet: The Omnivore’s Solution by Roy Mankovitz

2009 – Primal Body-Primal Mind by Nora Teresa Gedgaudas

2009 – The Primal Blueprint by Mark Sisson

2009 – Catching Fire: How Cooking Made Us Human by Richard Wrangham

2010 – The Paleo Solution, by Robb Wolf

2010 – ‘The New Evolution Diet: What Our Paleolithic Ancestors Can Teach Us about Weight Loss, Fitness, and Aging by Arthur De Vany

2011 – ‘Everyday Paleo‘ by Sarah Fragoso (Foreword by Robb Wolf)