In Part III, we established the following:
- Bipedalism among human ancestors is associated with a dietary shift away from soft, sugar-rich fruit, and toward hard, fibrous, ground-based foods like nuts, root vegetables, insects, and mushrooms. (And perhaps some meat, though the evidence is inferential.)
- Both bipedalism and this dietary shift occurred while our ancestors were still forest-dwellers—before we moved into savanna and grassland habitats.
- Both bipedalism and this dietary shift preceded the massive increase in our ancestors’ brain size.
- Therefore, neither fruit, nor potatoes, nor walking upright made us human.
Once again, I am giving what I believe to be the current consensus interpretation of the evidence…and where no consensus exists, I offer what I believe to be the most parsimonious interpretation.
(This is a multi-part series. Go back to Part I, Part II, Part III.)
A Quick Recap
4.4 million years ago, Ardipithecus ramidus still had a brain the size of a modern chimpanzee, but was a facultative biped partially adapted to a ground-based diet. By 4.1 MYA, Australopithecus anamensis had been selected for more complete dietary adaptation:
Science 2 October 2009: Vol. 326 no. 5949 pp. 69, 94-99
Paleobiological Implications of the Ardipithecus ramidus Dentition
Gen Suwa, Reiko T. Kono, Scott W. Simpson, Berhane Asfaw, C. Owen Lovejoy, Tim D. White“Ar. ramidus lacks the postcanine megadontia of Australopithecus. Its molars have thinner enamel and are functionally less durable than those of Australopithecus but lack the derived Pan pattern of thin occlusal enamel associated with ripe-fruit frugivory. The Ar. ramidus dental morphology and wear pattern are consistent with a partially terrestrial, omnivorous/frugivorous niche.”
And the Laetoli footprints show that hominins were fully bipedal by 3.7 MYA, though we have no evidence for brain size until…
Australopithecus afarensis: Upright Gait, Smaller Body, Bigger Brain
Australopithecus afarensis lived from approximately 3.9 to 2.9 MYA. (Once again, these are human-drawn distinctions between a continuum of hominin fossils.) It was slightly shorter than Ardipithecus (3’6″) and weighed much less: 65# versus 110#. The famous “Lucy” fossil is about 40% of an A. afarensis skeleton from 3.2 MYA.
Lucy might have looked like this.
Additionally, its back had a similar double curve to modern humans; its arms were shorter than Ardipithecus; its knees support an upright gait, and its feet had arches like ours—meaning that it was fully bipedal, and that A. afarensis is very likely the hominin which made the Laetoli footprints.
This is a recent finding: only last year did its discoverers announce that they had found a foot bone from A. afarensis which appears to settle this long-simmering question.
Science 11 February 2011: Vol. 331 no. 6018 pp. 750-753
Complete Fourth Metatarsal and Arches in the Foot of Australopithecus afarensis
Carol V. Ward, William H. Kimbel, and Donald C. Johanson“A complete fourth metatarsal of A. afarensis was recently discovered at Hadar, Ethiopia. It exhibits torsion of the head relative to the base, a direct correlate of a transverse arch in humans. The orientation of the proximal and distal ends of the bone reflects a longitudinal arch. Further, the deep, flat base and tarsal facets imply that its midfoot had no ape-like midtarsal break. These features show that the A. afarensis foot was functionally like that of modern humans and support the hypothesis that this species was a committed terrestrial biped.”
Most importantly, A. afarensis’ brain was much larger than Ardipithecus: 380-430cc versus 300-350cc. This means that selection pressure was favoring bigger brains as early as 4 million years ago, while allowing our ancestors’ bodies to shrink dramatically.
Now we’re getting to the meat of the problem. What could have caused this selection pressure?
“Is It Just Me, Lucy, Or Is It Getting Colder?”
During the Pliocene (5.3-2.6 MYA), the Earth’s climate—though far warmer than today’s—become cooler, drier, and more seasonal (see the temperature graphs and detailed explanation in Part I), a multi-million-year trend which began with the Middle Miocene Disruption around 14.5 MYA. Consequently, African forests were shrinking, and savannas and grasslands were growing in their place.
With less forest available to live in, some number of our ancestors faced a stark choice: adapt to living outside the forest, or die out. Those that stayed in the trees became what we know today as chimpanzees and bonobos. Those that eventually left became our ancestors—the hominins.
PNAS August 17, 2004 vol. 101 no. 33 12125-12129
High-resolution vegetation and climate change associated with Pliocene Australopithecus afarensis
R. Bonnefille, R. Potts, F. Chalié, D. Jolly, and O. PeyronThrough high-resolution pollen data from Hadar, Ethiopia, we show that the hominin Australopithecus afarensis accommodated to substantial environmental variability between 3.4 and 2.9 million years ago. A large biome shift, up to 5°C cooling, and a 200- to 300-mm/yr rainfall increase occurred just before 3.3 million years ago, which is consistent with a global marine δ18O isotopic shift.
…
Our results show that a diversity of biomes was available to A. afarensis. Recovery of hominin fossils through the entire stratigraphic range suggests no marked preference by A. afarensis for any single biome, including forest. Significant cooling and biome change had no obvious effect on the presence of this species through the sequence, a pattern of persistence shared by other Pliocene mammal taxa at Hadar and elsewhere (6, 27, 32). We hypothesize that A. afarensis was able to accommodate to periods of directional cooling, climate stability, and high variability.
As we found in Part I, and as we’ve seen by the chimp-sized brains of Ardipithecus, shrinking habitat does not explain increased brain size by itself—but it does provide an incentive to find ways to live in marginal habitat, or entirely different biomes. And it’s clear that bipedalism would be an advantage in forest margins and open forests, where direct travel from tree to tree wasn’t possible. In addition, more light reaching the ground would mean more food available on the ground, versus up in the tree canopy—so bipedal ground-dwelling would have been a good survival strategy in forest habitat that was marginal for a tree-dweller.
My interpretation of the evidence is that bipedalism did not cause brain expansion, but it was a necessary precondition. It allowed our ancestors to expand beyond the forest margin—and it freed up our ancestors’ hands for other tasks, such as…
How Bipedalism Enables Tool Use, Re-Use, and Manufacture
Facultative bipeds, which cannot walk on two legs for very long, can’t carry tools around with them: they must make a tool out of whatever materials exist near the point of use, and discard it soon after. Therefore, the tools they make must remain relatively simple, since they can’t spend too much time making single-use items—and it greatly constrains the raw materials they can use. (Yes, I’m ignoring any hypothesis that gives Ardipithecus ramidus the ability to construct backpacks.)
In contrast, full bipeds can carry around their tools in anticipation of needing them, and can keep them for future use. Therefore, they can spend the time and effort to make complex, reusable tools—and they can use any raw materials they have access to, not just those near the point of use.
We know that modern chimpanzees make spears, termite sticks, and other wooden tools—but is there evidence for tool use previous to the Oldowan industry, 2.6 MYA?
Recall that the Oldowan industry marks the beginning of the Paleolithic age, and happens to coincide with the beginning of the Pleistocene epoch. (If these terms are confusing you, I explain them in Part II.)
Rocks, Meat, and Marrow in the Pliocene
Nature 466, 857–860 (12 August 2010) — doi:10.1038/nature09248
Evidence for stone-tool-assisted consumption of animal tissues before 3.39 million years ago at Dikika, Ethiopia
Shannon P. McPherron, Zeresenay Alemseged, Curtis W. Marean, Jonathan G. Wynn, Denné Reed, Denis Geraads, René Bobe, Hamdallah A. Béarat“On the basis of low-power microscopic and environmental scanning electron microscope observations, these bones show unambiguous stone-tool cut marks for flesh removal and percussion marks for marrow access. … Established 40Ar–39Ar dates on the tuffs that bracket this member constrain the finds to between 3.42 and 3.24 Myr ago, and stratigraphic scaling between these units and other geological evidence indicate that they are older than 3.39 Myr ago.”
It’s fair to say that no one knows what to do with this particular piece of evidence, so it tends to simply get ignored or dismissed. What we know is that the researchers found several ungulate and bovid bones, dated to 3.4 MYA, which were scraped and struck by rocks. The scrapes are not natural, nor are they from the teeth of predators, and they appear to date from the same time as the bones.
One of the bones at Dikika. The reality of paleontology is far less exciting than the hypotheses it generates.
Unfortunately, no stone tools or fossil hominins were found there, so we can’t say for sure who made them. But the simplest interpretation is that a hominid used a rock to scrape meat off of the bones of large prey animals, and to break them open for marrow.
It is likely that the reason this evidence isn’t more well-accepted is because the researchers make one huge assumption: that the scrape marks were made by deliberately fashioned stone tools, 800,000 years before the first evidence we have of stone tool manufacture—even though no such tools were found.
I believe the most parsimonious interpretation is that the scrape marks were indeed made by Australopithecus afarensis…using one of the naturally-occurring volcanic rocks found in abundance in the area. Given the slow pace of technological change (millions of years passed between major changes in stone tool manufacture, and that’s for later hominins with much larger brains than A. afarensis), it would be extremely surprising if naturally-occurring sharp rocks hadn’t been used for millions of years before any hominin thought to deliberately make them sharper—
It’s Not Just The Discovery…It’s The Teaching And The Learning
—and, more importantly, before their children were able to learn the trick, understand why it was important, and pass it on to their own children.
Those of you who were able to watch the documentary “Ape Genius”, to which I linked in Part I, understand that intelligence isn’t enough to create culture. In order for culture to develop, the next generation must learn behavior from their parents and conspecifics, not by discovering it themselves—and they must pass it on to their own children. Chimpanzees can learn quite a few impressive skills…but they have little propensity to teach others, and young chimps apparently don’t understand the fundamental concept that “when I point my finger, I want you to pay attention to what I’m pointing at, not to me.”
So: the developmental plasticity to learn is at least as important as the intelligence to discover. Otherwise, each generation has to make all the same discoveries all over again. It is theorized that this plasticity is related to our less-aggressive nature compared to chimpanzees…but that’s a whole another topic for another time.
In conclusion, the Dikika evidence pushes meat-eating and stone tool-using (though not stone tool-making) back to at least 3.4 MYA, well into the Pliocene. And though we’re not sure whether that meat was obtained by hunting, scavenging, or both, we can add it to the other foods that we’re reasonably sure formed its diet to produce the following menu:
The Paleo Diet For Australopithecus afarensis
Eat all you can find of:
- Nuts
- Root vegetables
- Insects
- Mushrooms
- Meat (particularly bone marrow)
Eat sparingly:
- Fruit (your tooth enamel won’t withstand the acids)
- Foliage (your teeth aren’t shaped correctly for leaf-chewing)
In other words, A. afarensis was most likely eating a diet within the existing range of modern ancestral diets—3.4 million years ago.
The only major addition to this diet previous to the appearance of anatomically modern humans is the gathering of shellfish, known from middens dated to 140 KYA at Blombos Cave.
Our Takeaway (so far)
- Our ancestors’ dietary shift towards ground-based foods, and away from fruit, did not cause an increase in our ancestors’ brain size.
- Bipedalism was necessary to allow an increase in our ancestors’ brain size, but did not cause the increase by itself.
- Bipedalism allowed A. afarensis to spread beyond the forest, and freed its hands to carry tools. This coincided with a 20% increase in brain size from Ardipithecus, and a nearly 50% drop in body mass.
- Therefore, the challenges of obtaining food in evolutionarily novel environments (outside the forest) most likely selected for intelligence, quickness, and tool use, and de-emphasized strength.
- By 3.4 MYA, A. afarensis was most likely eating a paleo diet recognizable, edible, and nutritious to modern humans.
- The only new item was large animal meat (including bone marrow), which is more calorie- and nutrient-dense than any other food on the list—especially in the nutrients (e.g. animal fats, cholesterol) which make up the brain.
- Therefore, the most parsimonious interpretation of the evidence is that the abilities to live outside the forest, and thereby to somehow procure meat from large animals, provided the selection pressure for larger brains during the middle and late Pliocene.
Live in freedom, live in beauty.
JS
We’re not done yet…in fact, we’re not even to the Paleolithic! Continue to Part V, “Why Are There Southern Apes In Ethiopia?”
Are you enjoying this series, or is it too abstruse for you? Please leave a comment and let me know!
J. Stanton,
I find this series really interesting. I have a personal interest on the isotopic evidence for meat consumption in the paleolithic, but I think you already intend to comment on that in the future posts…
I have some references on that, if you want some you can mail me.
Keep up the good work…
Tiago.
brilliant write up J Stanton, concise and logical.
I’ve been eagerly awaiting the next instalment, and it has left me wanting even more. Great write-up.
This is very interesting series for me and I eagerly wait for new posts.
I wondering how did A. afarensis females deliver babies with bigger skull.
All humans deliver premature babies compared to chimpanzees or gorillas, I want to understand when did this evolution happened. It happened in A. afarensis or Homo Erectus or Homo Sapiens.
Enjoying it immensely!
This is awesome. One of the few times I see that elusive beast … “science”. I love it.
[…] Read More » […]
Love the series, keep it rolling.
i’m enjoying it, and finding it very interesting, too — much further back in history than i’ve ever studied! 🙂
Love it! Glad you are back; I’ve missed your superb research and great writing!
What kinds of nuts and roots were they eating?
JS, great writing! i hope i speak for everyone when i say, i’m not even quite positive what abstruse means, but i’m pretty sure i enjoy all of the information dense articles much the same as i enjoy my nutrient dense foods
keep it comin’, please
Lovin’ it! The more parts the better. It makes great sense that even if kids learned by watching that you grab a sharp stone, it would be a huge next step to purposefully make your own sharp stones especially since it wouldn’t be a one- or two-step process.
I’m having a great time with this. I have an undergrad degree in anthro. So it complements what I’ve studied in this area. Thanks.
simply brilliant.kudo
young chimps apparently don’t understand the fundamental concept that “when I point my finger, I want you to pay attention to what I’m pointing at, not to me.
I have a small one year old baby and I feel astonished how quickly she understands new words. In nine months she understood what pointing finger means. Human babies learn quickly still females reach puberty much later then chimps. Seems human females required longer time to learn to take care of babies compared to chimps (Because babies are born premature). Neanderthals reached maturity earlier then humans may be this shows they were also learning faster then humans.
This also could mean Neanderthal babies required less care.
Tiago:
Email sent.
eddie, Octavian:
Thank you for the support. These articles aren’t sparking a lot of discussion, so it’s good to know that my readers appreciate reading them.
Vizeet:
That’s an excellent question. I don’t think we know their size at birth: fossil evidence is so thin that we’re lucky to have any idea what the adults looked like! Entire species are implied from jawbones, a few teeth, and part of a humerus (A. anamensis), which leaves a hole in the brain-size data since we have no cranial remains.
Wayne:
You’re welcome.
Mary:
I’m glad you appreciate the science, because it’s hard work! I love the process of learning and teaching, but I understand why pot-stirring is so much more popular: it’s easier by far.
(Note to all: the best way to say “thank you” is to buy a copy of The Gnoll Credo or a T-shirt.)
Bodhi:
Glad you’re back! I hope you’re well.
We don’t know exactly which of nuts and tubers they were eating, because that sort of evidence doesn’t fossilize…but palynological evidence (pollen) can at least tell us the type of biome they lived in and what sorts of plants were in it. Then, dental and cranial analysis tells us what sort of foods they were adapted to eat, and dental wear analysis can sometimes tell us more about the dietary mix they actually ate.
tess:
Most history books start with “The Great Leap Forward”, i.e. the Neolithic Revolution — as if nothing at all happened previous to agriculture. The reality, of course, is that everything happened…
…we became human!
Jackie:
Much appreciated.
mark:
“Meat For The Mind” is now a trademark of J. Stanton 🙂
Nance:
Yes. The mental process of imitation is very different than the mental process of discovery.
Terry:
Wonderful! Please fact-check me, and suggest possible improvements if you see any.
pam:
Thanks for the kudo! It was lonely at first, but then I got a couple more so they’re all happy.
Vizeet:
Young chimps are better at problem-solving than young children, but they’re not as good at learning by imitation.
There’s so much fascinating speculation to be done about Neandertals…I’m sure one will be cloned up at some point.
Thanks, everyone, for your votes of confidence! I’m glad you’re willing to follow along with this deep and technical anthropology. Paleo has progressed dramatically over the past two years, so in order to discover new knowledge, we must work harder than before.
JS
Enjoy. Thanks very much!
You’re really cranking these out lately, JS. fascinating food for thought and certainly a possible way to fill in some of the blanks left in the standard story.
One possibility I often see largely ignored is the effect of swamp land on bipedality. Particularly, the need to carry babies while crossing water too deep to wade quadripedally. Do you know how much of the terrain during these periods might have been wetlands?
Interesting, thanks, J!
Regarding:
Eat sparingly:
Fruit (your tooth enamel won’t withstand the acids)
Foliage (your teeth aren’t shaped correctly for leaf-chewing)
It seems unlikely that they’d have avoided fruit because they knew it wasn’t good for their teeth. If it was available and palatable, they’d surely have eaten it, no?
Likewise for foliage, if it was edible, they’d have eaten it–at least as much as their teeth would allow.
You don’t seriously suggest that avoiding fruit was cultural knowledge passed from generation to generation, do you?
@Dave Sill, more likely that it just wasn’t as available, so they ate sparingly of it out of availability, therefore their teeth lost the adaptations necessary to support high fruit consumption.
Dear JS,
Are you really wondering if we, the restless followers of your great work, are enjoying this series? If it helps you sleep at night I´m here to say thank you for this mind-shocking, soul-warming piece of scientific-yet-incredibly-novelesque reading.
Please, PLEASE never stop writing.
Sincereley,
Juan
PS: PFMPIE (Please Forgive My Probably Imperfect English)
🙂
Samantha:
I appreciate the support.
Uncephalized:
As far as I know, the terrain was more “forest” than “swamp”.
The problem with babies and the bipedal transition is that baby monkeys hang onto their mothers with their hands and feet. Once you lose the opposable toes, you can't hang on nearly as well, so your mother has to carry you in her hands more often.
Of course, the idea is that you're spending more time on the ground and less up trees, or you wouldn't be losing the opposable toes!
JS
Dave:
Uncephalized answered that one for me. As they moved out of a fruit-heavy environment, there was less selection pressure for tooth enamel that withstood fruit acids. “Use it or lose it” applies in evolutionary time, too: any adaptation that doesn’t get used tends to disappear or become non-functional.
Uncephalized:
Exactly! If my other readers have the same grasp of the concept as you do, I consider my work in Part I to be a success.
Juan:
I’m honored, and I’m glad I could bring part of our ancestors’ history to life for you.
Everyone:
Your comments are greatly encouraging. What with all the arguments, mud-throwing, confusion, and zombie-like resurrection of debunked papers and failed hypotheses going on right now (see my article from last year in which I debunked the “boiled potatoes are the most satiating food in the universe!1!11!!” paper that’s shambling its way through the blogosphere right now), I’m glad that my readers still enjoy calm, patient exploration of scientific fact. While I still love everyone involved, eating a couple potatoes is NOT a political act on par with MLK’s “I Have A Dream”, and does not require the invocation of “food reward” to explain its metabolic effects.
Thanks again to all of you here at gnolls.org for keeping the discussion here on a higher level, both of intellect and of civility.
JS
Just chiming in to say it’s normal that this kind of article has less of a discussion going, since they’re mainly stating facts, and that that’s by far not a bad thing. Scientific divulgation rarelly gets the treatment it deserves.
Btw, since you mentioned, do you plan on going back into “why are you hungry” after this?
Fmgd:
You're right: I'm not issuing a lot of opinions for people to argue about — and that's the point. I'm trying to forestall those arguments.
I'll definitely come back to “Why Are We Hungry?”, but I won't commit to a firm date.
JS
As a “thinny”, as someone more interested in the paleolithic than modern paleo diets, as someone interested in eating like a human and dare I say it? as a European. I can’t believe that fatness/thiness is still being used as THE health marker in the “potatoes or not” discussions.
in addition, oatmeal more satiating than eggs?? Porridge (to give the stuff it’s proper name)has got to be the least satiating food of all time!
“I’m glad that my readers still enjoy calm, patient exploration of scientific fact.”
That’s why I keep coming back to Gnolls. It is an oasis of thoughtfulness and calm. (Heated) debate is good, and some of the fiery debates currently raging in the paleosphere are necessary to move us forward, but sometimes I struggle with the signal to noise ratio.
That is NEVER a problem here.
I think that potatoes are quite satiating… per calorie and eating nothing but potatoes
Its difficult to overeat even if you want. But if you want to reach your 20 potatoes, you have to “graze”. You can’t gorge, you need to keep eating all the potatoes you can and wait one or two hours to graze again.
But, c’mon! who would like to eat like that? only Chris Voigt
You will loose weight
You could throw some offal and a little animal fat because it’s daunting to eat 20 potatoes per day. You also will loose weight. The potatoes also have good micronutrients. But offals are the kings.
You will heal your metabolism and loose fat. With the offal and fats, you will also like it
But there are other ways to loose fat. And those wich aren’t overweight don’t need to loose fat.
If I were overweight I probably try the potatoes thing. I mean, potatoes appears to be a good food to control appetite.
Potatoes is a good staple food. Excellent food. But also animal fats. And offal (in moderation, you don’t want to end with hipervitaminosis A)
I like the animal foods more, but I also like potatoes, sweet potatoes, etc.
Neal:
That's an artifact of individual bloggers' personal struggles. People generally don't make huge dietary changes without massive health problems to force them into it — and in America, obesity and its consequences are by far the most common.
I'm glad you can easily see why that “satiety” study is bunk. Frankly, anyone who cites it as serious science either didn't read it, didn't understand it, doesn't understand the scientific definition of “satiety”, or has an ulterior motive that is not scientific at all. (Or some combination of these.)
(Note: I forgive the community for seizing on it, because the fulltext isn't free.)
Asclepius:
You're a big reason why gnolls.org remains “an oasis of thoughtfulness and calm”. (As are my other frequent commenters.) It only takes a couple hotheads to light a place on fire.
christopher:
I'm not anti-potato by any means…I have a bag in my kitchen! Unlike most starches, they contain some useful nutrients, and the common varieties are very low in antinutrients so long as you peel them…I don't buy the “sweet potatoes only” hype.
However, let's be clear: plain boiled potatoes aren't necessarily satiating…they're just bland and gross, which is to say they have low hedonic impact, which is to say that we don't “like” plain boiled potatoes very much. Since they're so bland and gross, it takes very little satiation to make us stop eating them.
The trouble, of course, is as you noted: you have to keep grazing on them throughout the day, because you haven't actually been eating much and your body needs the energy. Stated in scientific terms, “Palatability affects satiation but not satiety” — the title of a study I cite in Part VII of “Why Are We Hungry?”.
And that's why eating foods low in hedonic impact (called “low-reward” foods by those unfamiliar with the science), like boiled potatoes, doesn't necessarily solve your dietary issues: if you eat less food because food is disgusting, you'll just get hungry again more quickly. Satiety is only produced by nutrients.
Clear?
JS
I love your blog JS. I was just wondering what your academic background is- are you a specialist or a generalist in academe?
I’m really looking forward to your upcoming articles in this series. One thing that confuses me is that of the Neanderthals. They were bigger, stronger, presumably consumed a diet very heavily meat based (esp large terrestrial ruminants) and most importantly had larger cranial capacities. Why did they become extinct? Are they not more in tune w the gnoll credo than homo sapiens?
sonny:
We're a long way in time from the Neandertals just yet!
No one is sure why they died out. However, I'm quite sure they didn't just passively expire and cede their territory to Homo sapiens sapiens…I believe there would have been quite a bit of direct conflict, with our ancestors the eventual winner. And since the Neandertals were substantially stronger, more physically capable, and had larger brains than humans, I believe the advantage had to be technological in nature.
I'm an academic generalist — one of the few remaining polymaths in a world of increasing specialization. (I've taken anthro and paleo courses, but neither was my degree field, and we certainly didn't cover this era in such detail. Furthermore, many of these important fossil finds only went public in the last few years, and postdate my classes in the subject!)
JS
Hey sonny, I don’t want to steal JS’s thunder, H.neanderthal was quite a bit shorter than H.sapiens but yes probably much stronger and more robust. They seem ot have eaten a broadly similar diet to H.sapiens too.
They dissapear at a time of greatly increasing cold and deforestation. Depends who you ask but it would appear that “we” were better able to deal with changing circumstances.
I think I may have found the answer to my own question, I did a bit of googling and found this article from BBC Feb.27-“DNA reveals Neanderthal extinction clues”
http://www.bbc.co.uk/news/science-environment-17179608
Very interesting, they’re saying that most of the Neanderthals died out BEFORE Homo Sapiens arrived in their environment. When sapiens did arrive, the Neandertals’ population size and diversity were v much diminished (less diversity than present day Iceland!) I guess this means they could’ve easily been either absorbed or killed off by sapiens. Heck, even a new pathogen imported by sapiens could’ve killed them off.
Its like a territory w 10 grizzlies and 5000 black bears. Yeah, the grizzlies are superior predators, but in a v short time they’re going to be wiped out/absorbed.
So, I guess the most parsimonious explanation would preclude a technological advantage by sapiens. ie: they were probably superior to us, and it was just dumb luck that allowed us to survive and not them.
—–
Whatever neanderthal genes were admixed into ‘european’ DNA was most likely a fortunate event and may have even (partially) laid the foundations for future civilization.
“Uncephalized:
Exactly! If my other readers have the same grasp of the concept as you do, I consider my work in Part I to be a success
Well, I can’t give you credit for my grasp of evolution and natural selection, though you do write about them well. I had to read a lot of Dawkins to achieve the level of intuitive fluency with the ideas that I enjoy now–although “had to” is not really the best way to phrase it as I thoroughly enjoyed every book!
If anyone has trouble with understanding how evolution and natural selection work at the fundamental level, I can’t recommend anything more highly than reading The Selfish Gene, and then probably reading it again. That book is a life-changer (not unlike The Gnoll Credo!).
Oops, missed closing a tag and a quote above I guess. The first two paragraphs were meant to be quoted and italicized.
Neal:
The narrative keeps changing as we find more data, which is why I clearly mark my opinions as speculation. Their diet seems to be more strongly carnivorous, which coupled with greater weight would imply a lower population density. And since the Neandertals had been in Europe for several hundred thousand years, i.e. more than one ice age, I'm not sure that climate change explains everything.
sonny:
That's a great study (and it just came out!), but it only covers Western European populations. Remember that Neandertals ranged all the way down into the Middle East. It's entirely possible that when humans finally broke through the Middle Eastern population, that the Western European population had already been depleted and was eliminated relatively quickly. And I find it interesting that the last traces of their occupation are all the way out on Gibraltar…that's not a pattern of climactic extinction, it's a pattern of being eliminated by H. sapiens spreading from Africa through the Middle East.
Again, I'm a bit skeptical about attributing the population bottleneck purely to climate change, as the Neandertals had already survived one Ice Age in Europe. But it's certainly possible, and these are fascinating questions to think about even if we can't definitively answer them.
Uncephalized:
Yes! I agree that The Selfish Gene is Dawkins' most important work, with The Extended Phenotype a close second (note: it's tough going, and should be read after The Selfish Gene). However, many people will be best served by starting with The Blind Watchmaker so they're well-grounded in evolutionary theory before going into its deeper consequences.
I also agree with you that they're important and life-changing works. Furthermore, I strongly believe that a gut-level understanding of natural selection is necessary to understanding anything about human behavior, animal behavior, or the world in general.
Thank you for the implied compliment! If my impact on you ranks anywhere near Richard Dawkins, that's a great honor.
JS
[…] J Stanton gives us the next big thing: the Australopithecine Paleo Diet. […]
JS, Nice summary. Thanks for providing one of the few, and one of the better, counterpoints to Wrangham’s cooked-tuber hypothesis of brain growth in the nonraw Paleosphere. Too many folks in the Paleosphere seem to read a few snippets of Wrangham’s views and quickly embrace them, perhaps because they perceive his model as supporting what they want to do (“Hooray! I can eat all the cooked food I want, including french fries and crispy fried bacon, because cooking is what gave us big brains!”), ignoring the counter-evidence.
Paleophil:
We're a long way from Wrangham yet! He posits that cooking began at appx. 1.6 MYA, and we're only to perhaps 2.9 MYA just yet. Of course, our ancestors' brain size was already increasing by 2.9 MYA (not to mention by 1.6 MYA), we had already started occupying habitats outside the forest, we were already eating meat — and even the most optimistic archaeologists won't claim evidence for control of fire that far back.
There are many more conflicts between “Catching Fire” and the evidence — but as I said earlier, I don't want to interrupt this narrative to debunk alternatives. I'd rather present the current consensus interpretation first, so that we have something solid with which to compare the “cooked tuber hypothesis”.
JS
wow
I just read all your articles of “why we are hungry”.
I quit what i said about trying the potatoes thing.
I’m probably biased with potatoes, because i like them.
I had been in poverty. Some days we eated wheat (pasta and bread). I loved when we switched to rice or potatoes. And ocasional meat, with offals. And soups with bones. The potatoes were my staple food a few years, and i grew up healthy. So i’m a proof that potatoes are quite good. Living in a country with much beef consuption (argentina), i was resigned to not eat them. but now i can catch up.
look at this: feature=related
Most of the turists find it disgusting, but it’s delicious.
Human diet is surprisingly varied across the world.
I remembered the whole food reward thing today, I think I found a breakthrough for it.
I had some sardines so I decided to boil their heads and tails together with a couple marrow bones and use it all to cook some rice.
As you’d expect the result was sardine-tasting rice. Thing is, I forgot all about the fish-bones. So there I had a pretty “strong” sadine-tasting rice with eggs and lots of pin bones.
The result was that you had to conciously chew on that rice and eat with extreme care, which of course made all it a lot harder to eat.
So yeah, instead of focusing only on “low reward”, why not add high effort to your meals. Can you imagine bland mash potatoes loaded with these bones? There’s no way you could overeat them even if your day had thirty-some hours.
I am taking cue from this post. I think it is very difficult to create fire just like making tools so there has to be a phase in which our primates just started using natural occurring fire.
JS: “If my impact on you ranks anywhere near Richard Dawkins, that’s a great honor.”
Different kind of impact. You’re more in the genre of Daniel Quinn (although you tell a better story. than Quinn), making me think about people’s place in the world, what people should be. They’re important ideas in different ways.
[…] Reblogged from Gnolls.org […]
christopher:
Chitterlings, chicharrones, chinchulín, tripas … it's all intestines. And I love me a good asado!
Potatoes are actually my favorite starch, since they're reasonably nutritious. Many Irish lived on a 100% potato diet and were perfectly healthy — right up until the famine.
Fmgd:
That's a great experiment! As I've explained in the series, satiation is our estimate of future satiety based on the sensory experience of eating. As such, anything we do that makes us concentrate more on what we're eating is likely to increase satiation…and trying to pick bones out of rice certainly qualifies.
vizeet:
There is good evidence that you are probably correct, which I'll get to in future installments…and it explains a lot of things about the evidence we do have.
I think it's great that my readers are smart enough to get ahead of the narrative!
Uncephalized:
“They're important ideas in different ways.” Absolutely true…but they all tie together.
If we want to talk about what humans should be, we must first understand what humans are. To understand what humans are, we must understand how humans came to be. Therefore, the modern Darwinian synthesis must be the foundation of any moral or political discourse.
And, in my opinion, of any realistic story…I've always been bothered by questions like “When elves aren't busy being beautiful and noble and awesome, what do they eat? Where are the farmer elves?” Tolkein's work was fundamentally Catholic and ignored those questions, as do most fantasy writers. Either that, or they go all “edgy” and wallow in nastiness.
That's why TGC isn't a fantasy novel, despite containing gnolls and other fantastic creatures.
“although you tell a better story than Quinn”
Thanks for noticing. If he deserves half a mil for Ishmael, I figure I deserve at least a few mil for TGC 🙂
JS
J.S. Please keep writing, I love the way that you spin a story so it makes sense for those of us with non-technical backgrounds. You make it so we can understand and explore on our own without being told what to think. After reading the Why We Are Hungry series and now this one I can’t wait until my copy of the Gnoll Credo arrives.
Hi J, sorry I didn’t check the comments of this blog. I would have thought a new animal sharing the same (or similar) ecological niche might be one reason neanderthal couldn’t weather the drop in temperatures and ecosystem cnange they saw at the end of their line.
I have often wondered how the elves got their bread too.
Mike:
I'll keep doing my best to make science understandable.
Block out some uninterrupted time for TGC: it's an intense book.
Neal:
Do you have any idea what that animal might be?
“I have often wondered how the elves got their bread…”
Orcs, too. As far as I can tell, every orc is either in the military or on the Middle-Earth equivalent of a chain gang. For that matter, what are all the creatures in Sauron's realm eating if the whole area is such a fiery wasteland? Each other?
(Note that I'm not slagging on Tolkien's work: those sorts of details would have bogged down the story. I'm just pointing out that LoTR is a movie set for an Epic Quest, not a functional universe people could actually live in.)
JS
From the 1969 LOTR parody Bored of the Rings:
on the neanderthal point, having read the bbc article above just now, there is probably a combination of factors.
if they were bigger than H sapiens then they may have had a longer breeding cycle, so although they were more proficient in any conflict they would have recovered slower.
their culture may have been more introverted so they interbred with lower frequency, further reinforcing above.
also though simple fear of the different could have caused conflict easily enough, look at how we are now with those we see as “different” (by we i mean humanity as a whole, not individuals)
Hi J that animal would be us, I’m not wild about tolkien but I remener he wrote that there were fields in mordor worked by slaves. I think he talked about food being shipped in too.
Neanderthal was bulkier but by no means bigger than H.sapiens. A neanderthal in a cage fight would be pretty bloody intimidating though. Off the top of my head I believe the view is that neanderthal matured earlier.
Ground nuts bark and dirt, low in food reward eh? ho ho ho
“Many Irish lived on a 100% potato diet and were perfectly healthy — right up until the famine.”
No, not 100%.
While potato was the predominant food of the cottier class, each family raised some hens, a pig or two and often a cow.
My judgement is that the diet was similar to the present-day Kitivans, 60-70% tubers. They used butter-milk, eggs, “bacon&cabbage” and so on for the other 30-35% of their diet. They also foraged for seasonal wild fruits and nuts, seaweed where appropriate and some shellfish.
They did not not eat bread: wheat was a cash crop for the British industrial worker.
The Scots had a similar reliance on the potato as did some other European countries. It was potato blight in two successive years that devastated Ireland’s main food source.
There was blight in other parts of Europe, but nowhere as severe as that in Ireland.
As an aside, the 2nd and 3rd sons provided a proportion of the 19th century British Army vastly higher than that of the population of England. Recruiting officers wanted them.
I live in India and I have heard that many poor people in north India ate almost just potatoes during famine.
My diet have always been high in potatoes and I love them.
garymar:
Remember back when National Lampoon was funny?
eddie:
Most likely. Tolerance for members of another species competing for your environmental niche would seem to be strongly selected out of the gene pool.
Neal:
It's admittedly been a while since I read it…but those armies of Mordor are pretty big. I figure Soylent Green had to have been a frequent menu item.
Neandertals were definitely bigger and heavier than H. sapiens sapiens of the time, though they were perhaps 6″ shorter on average — and we're reasonably sure that they did, in fact, mature more quickly than we did.
LeonRover:
According to the statistics I've seen, over 3 million Irish — more than 1/3 of the population — were wholly dependent on the potato for food at the beginning of the Great Famine. This statistic is bolstered by the fact that over a million Irish died and over a million emigrated to escape it.
Note that Ireland still has not regained the population it had previous to “the bad times” — and, in fact, its population continued to fall until 50 years ago.
Vizeet:
Unlike almost any other vegetable food, it's apparently possible to stay alive for extended periods on a 100% potato diet. I wouldn't recommend it…but historically it's been done by many.
JS
I have checked a number of sources.
The adverb “almost” usually qualifies the term “wholly dependent” and the phrase “as main source of food” usually follows “potato”.
With that said, where a large proportion of a population suffers a loss of 2/3 rds of dietary intake, there is starvation and death.
As for “extended periods on a 100% potato diet”, it does not include periods of time which include procreation. Most former vegetarians , including Loren Cordain, concur.
Between 1800 and 1840, the population grew by 3m from 5m. This growth depended on very early marriage and farm splitting.
Post famine, late marriage became the norm, the eldest son inherited and emigration took care of the difference between birth rate and death rate.
LeonRover:
The presence or absence of qualifications depends on which source you’re reading. I don’t know enough about Irish history to make a firm judgment — and I’m certainly not advocating an all-potato diet! I’m just pointing out that unlike an all-grain diet, which produces beriberi, pellagra, kwashiorkor, or some other deficiency disease in relatively short order, an all-potato diet contains reasonably complete protein and enough other nutrients to avoid deficiency diseases for quite a while.
That’s the main reason the Irish population increased so dramatically AFAIK: not only are potatoes more productive per acre, they don’t require nearly as much supplementary nutrition from other sources as the grain crops (e.g. oats) grown previously to the potato. The combination led to the farm splitting you mention: farms that could only support one family on oats and sheep could suddenly support several on potatoes.
JS
Bored of the Rings was great! “Some Animals” was always my fav chapter.
Hasn’t been much to comment on, cuz we’re all waiting to see where this train is headed..
Jeffrey:
We already know that it's headed to anatomically modern humans. The interesting question is “by what route?”
Fortunately, by stopping at “anatomically modern” instead of “behaviorally modern” we simplify the problem dramatically…otherwise I'd be writing a textbook instead of a series of articles!
JS
I think after humans settled down (because of agriculture or for whatever reason) intelligence may have become less important then learning. Isn’t 10000 or so years enough to have some impact on our brains in this regard?
I’ve just discovered your site (two days ago) and am finding the articles fascinating. This particular series is excellent, your writing style keeps the story line engaging and informative without getting sidetracked down speculative rabbit holes. I look forward to the next installment. I’ve also placed an order for your book. So far so good, keep it coming!
Great stuff. Keep’em coming with this physical anthropology. I’m diggin’ it!~
I think if Neanderthals were at-least as intelligent as humans then they could have easily copied humans weapons if technology gave humans an edge. Neanderthals didn’t do that simply implies that humans projectile weapons did not have any advantage.
If I look into history the reason why Muslim rulers could rule India has nothing to do with intelligence, strength, numbers or weapons. They were able to win battles because they had better experience in fighting then we had. They might have found so many battles before they entered India.
Humans who entered into Neanderthals territory, may be having similar advantage.
Vizeet:
Absolutely: human brains have shrunk by roughly 10% since the advent of agriculture.
Re: projectile weapons, even if the Neandertals picked up the technology from Homo sapiens sapiens, their physical advantage of far greater strength would have been completely neutralized — and, in fact, their greater bulk (and, presumably, greater calorie requirement) would have become a disadvantage.
Matthew:
I'm glad you find my writing interesting, and I hope you enjoy TGC! Do stick around.
Luke:
Thank you. I'll be back to this subject soon.
JS
Have you encountered the book “Descent of Woman” by Morgan? It’s interesting; a lay anthropologist – aka housewife – did a poop-ton of research and made some alternate suggestions about the evolution of bipedalism and secondary sexual characteristics in humans, and was utterly ignored (or pilloried) for it, but her suggestion of a semi-acquatic phase including a lot of small fish in the diet would explain a lot of things about us (ability to hold our breath, watertight reproductive tract, loss of hair except for areas above the waterline (also explains loss of need for gripping baby toes), and most tellingly, subcutaneous fat. I’m not saying she’s got the whole thing tied up, but as I recall (that was 10 years ago) it was a pretty valid-sounding alternative, and worth exploring.
I don’t come to Gnolls regularly, but when I do I catch up and enjoy – as others have said – the calm consideration of what is known, rather than what is believed.
Lauren:
That would be the “Aquatic ape theory”, which just came up in the discussion for Part III. Pardon me for quoting myself:
“I don't see the evidence that [AAT] is true. There's no evidence that Ardipithecus or any other transitional bipedal hominins were aquatic in any way, either in behavior or in diet — and the fact that the transition to bipedalism preceded the increase in hominin brain size is evidence against it.”
It's very important to remember that when Morgan wrote her books on AAT, there was no fossil record of the hominin transition to bipedalism — so AAT was a plausible (though heterodox) alternative. The transitional fossils between the chimp-human divergence and the bipedal A. afarensis (Orrorin, Ardipithecus) were found very recently, and only publicized in the last few years! So it's only in retrospect that we can dismiss AAT.
(This is the problem with anthropology books…with so many important discoveries coming to light so recently, most printed matter is already out of date!)
JS
Love this site. It explains why I also like to crack open bones and suck the marrow.
Kenneth:
Thank you! There's something viscerally satisfying about eating meat on the bone, outdoors…because we've been doing it for millions of years.
JS
thanks for the gravlax recipe. good one. eat raw myself (will make exception for your sugar) and have “raw” fish every now and then, maybe 2x a month. raw eliminates your beloved potato pretty much but that’s ok. have you tried raw?
jane:
Gravlax is a great way to get people who “don't eat raw meat/fish” to eat raw fish! (Here's the recipe.)
No, I've never gone 100% raw for any significant period of time, though I've done it for perhaps two days. Not intentionally, though…usually because I'm on the road and eating gravlax and salads out of a cooler!
JS
Basically, you relate brain size with intelligence as Darwin and Mayr are doing. This seem to me the core of your argumentation. However, today, the range of human brain goes from 900cc to 2500cc without noticeable differences in intelligence or even better survival values. Moreover man’s brain is bigger, by at least 10%, than women brain without noticeable differences in intelligence. Moreover the Flores man, with a brain, the size of chimp brain, was capable of making the same tool as homo erectus.
To be fair to Darwin, I have to say that somewhere in his book, Descent of Man he backoff from brain size to composition of the brain. As for Mayr, in What Evolution is, he ends up by saying that there might be some neurons that are specifically humans.
Maybe, you are following a wrong trail.
roger:
First, I think you mean 900-1500cc, not 2500cc.
Second, intelligence in the modern era is roughly 1/2 dependent on cultural transmission (the probable source of the “Flynn effect”) and only 1/2 on innate capability — so it's risky to extrapolate from modern distributions to the Paleolithic, where cultural differences were much smaller and innate intelligence a much greater factor.
Third, you'll recall that Homo floresiensis was necessarily descended from either H. erectus or H. sapiens, meaning that its primitive stone toolkit was necessarily invented by ancestors with larger brains typical of hominins of the time. Chimpanzees can be taught to flake Oldowan stone tools, among other complicated behaviors…but there's no evidence that they've ever managed to invent them on their own.
While I don't think that cephalic ratio explains all of human intelligence, it's clear that larger brains are more energetically expensive than smaller brains — so there must have been some reason that they were selected for despite this handicap. If you don't think larger brains were necessary for the development of intelligence, it's your responsibility to come up with an alternative explanation for them!
JS
Hi Jim
Really, I should have wrote 400cc to 2200+ cc. 400cc about, for proportionates dwarfs as Jeffrey Hudson(18inches tall), Henrietta Moritz (22in) and Pauline Musters(23in). Dwarfs of Ecuador suffering from laron syndrome but very proportionates, seem to have about 700cc. At the other extreme, there are lord Byron, Oliver Cromwell and Yvan Turgenev with brain over 2200cc.
So, someone can be intelligent at about any brain size and also dim witted at 600cc as the gorilla, at 1000cc like the homo erectus, at 1500cc like the neandertal and even, seemingly, homo sapiens,from 150000 to about 70000 years ago.
roger:
I don't think Homo heidelbergensis and the Neandertals were dim-witted: try surviving in ice-age Europe without the benefit of modern technology — or any technology at all beyond sharp rocks you made yourself.
In fact, since all the things we think of as “culture” post-date the emergence of anatomically modern humans, it's clear that surviving as a hunter-gatherer had to be very mentally demanding: otherwise our ancestors wouldn't have developed these big brains in the first place!
Yes, there's a great deal of variation in modern brain size…but the fact that it's decreased over 10% since the invention of agriculture should tell us something. Also, culture and education creates roughly half of what we think of as “intelligence”…but I do note a distinct lack of genius proportionate dwarves in the historical record. And it turns out that Stephen Jay Gould's The Mismeasure of Man was a deliberate fraud. So while I believe that enough other confounding factors exist that cranial capacity doesn't tell us much about the capabilities of any individual modern human, I think it's reasonable to use its average as a proxy for relative intelligence of hominins in archaeological time.
JS
Sorry, I have used dim witted because of two things. First, during many thousand years, there were no significant changes in their technologies which remained about the same for heidelberg, neandertal and even homo sapiens sapiens until about 50 to 60000 years ago. Second, it seems that they could not make knots or untie or untangle knots. And, only us, among animals are capable of doing that easily. Why?
What brougth the so called Great Leap Forward, 40,50 or 60000 years ago, is the real question but you did not speak about that
roger:
We're still in the Pliocene at this point. The so-called “Great Leap Forward” post-dates anatomically modern humans, and is still several million years in the future.
JS
More skull findings: New fossil skull from Africa reveals tangled roots at base of the human family tree
This is the best overview of modern view on human evolution that I have come across, a real gem.
js290:
Great article! There's a good reason we see so many dotted lines and question marks in the evolutionary tree during the Pleistocene…there were several different hominins, and we're not exactly sure which ones were ancestral and which weren't.
WalterB:
Thank you! I'll continue adding to it in the future.
JS
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