Tag Archives: Archaeology

Everybody Always Gets This Wrong, Even Smart People

This is a great cartoon by Randall Munroe that makes a very important point very effectively. Spread it around, love it, learn from it.

Here is an excellent video walkthrough of the cartoon, discussing its value as a communication tool.

But do ignore the details of the prehistory because the cartoonist has fallen into the same trap so many others have, well meaning in intention but simply a) not an expert on key things and b) unaware of the real consequences of getting certain things wrong.

When we represent prehistory, we represent humanity both past and present. It is not difficult to do so in a way that leads to serious and meaningful, even impactful, misconceptions.

So, here, I’m going to complain not just about this cartoon, but about the general phenomenon of people who are not paleontologists or archaeologists (or some other appropriate expert) using human prehistory to make a point, but at the same time, throwing accuracy about that prehistory under the bus.

Right way, I want to point out the consequences: Westerners, for sure, but this is more widespread than that, tend to have a view of humans that involve concepts of civilized and primitive, and hierarchical concepts mixed with evolutionary ones. And there are other problems in the conceptualization of prehistory and the diversity of humanity. These problems make it very easy to maintain a racist perspective despite overwhelming evidence against the validity of biological race. These problems make it very easy to lessen the pain and suffering of certain people, which, often, we are busy causing in our own self interest. These problems in conceptualizing the nature of humanity across time and space lead to all sorts of misunderstandings with all sort of consequences including, but not limited to, simply getting it all wrong.

XKCD is a comic written in and fully appreciated by the context of modern skepticism and science cheerleading. Let us please not throw the important social and natural sciences of archaeology, prehistory, paleoanthropology, etc. under the bus in service of making a point in some other area of study. A smart man whom I respect quipped, “but this comic is not about archaeology.” My answer to that: This comic makes one point about climate change and dozens of points about archaeology. It is about archaeology.

Why this is a great cartoon.

Look at the cartoon. Go from top to bottom.

It tells us that over a very long period of time, as humans did all sorts of different things, and conditions on the earth changed dramatically, the global surface temperature a) remained within a fairly narrow range and b) didn’t vary that quickly even when it did vary.

Then, all of the sudden, temperatures shoot way up and are expected to shoot way up even more. Holy crap. Point well made.

Missed opportunities

The climate change science is not bad but a bit off. The baseline of temperatures (pre industrial) vs. now should be somewhat different in relation to the current temperature. If you take the last few thousand years as basline, which is the proper thing to do, we are closer to 1.5, and not 1.0, degrees C above it. But that may be a nitpick since the time scale of this cartoon is larger. But, once you get past that level of time scale, the question of baseline becomes untethered from pragmatics and you can justify anything.

Also, there are probably times in the past, within the time range of this cartoon, where more abrupt and dramatic climate change did indeed occur. And, at those times, major effects happens with humans.

This is where not getting the archaeology right causes the cartoon to both miss some key points and become inadvertantly somewhat less than straight forward.

Here’s the thing. Climate change can have a very negative effect on humans. How do we know? Because it apparently has happened over and over again. For example (and there are many examples), within the time range of this graphic, climate changed caused a significant increase in aridity in a huge area of southern Africa. The place was pretty well populated by hunter-gatherers before that, and after that, and for thousands of years, no one could live there. Climate change had made the region uninhabitable for humans.

Similarly, climate change probably caused depopulations, evacuations, and migrations in many other parts of the world at several points in time represented here.

Critics from the denier side of things would point out that climate change has always caused problems, so this new change is no big deal, and XKCD ignore this. But the cartoon, had it mentioned more of these earlier changes, would instead represent a different fact: Natural variation in climate can be catastrophic to humans. The level of change happening now, and expected in the near future, still caused by humans, is much larger than what happened during this time period, or faster. So look out!!!

But that’s not the point I want to make.

Simple facts and big concepts

NOTE: Since I wrote this post, at least one change was made in the original carton, pertaining to the flooding of the scablands in Washington State. Perhaps other changes will be made over time!

There are a number of simple facts that the time line either gets wrong or represents in a way that we would not like for a basic intro class in archaeology or paleontology. Some of these facts were pointed out to me by John McKay or Helga Ingeborg Vierich. This is not comprehensive, but gets the point across:

  • Impressive prehsitoric art appears on the cartoon at 15K. Art and adornmnent appear well before the time line begins, and jot just in Europe. The super impressive cave wall art dates well before the time line, and somewhat less impressive works occur very much earlier. This is a decades old conception overturned many years ago.
  • The Clovis First model of the peopling of the Americas is on its last legs and should not be used as assumed knowledge.
  • The Missoula mega-flods affected eastern Washington, not Oregon.
  • The glaciers weren’t just in New York and Boston, they covered many other places. If the idea is to connect glacial geography to people’s lives, references to other areas might be helpful.
  • Wrangle Island is not tiny. He may have confused Wrangle Island with Ts. Paul in the Privilovs.
  • Abu Hureyra is one of several sites with early year round settlement. More important may be the more southerly Natufian, where foraging peoples, for a very long time, took up permanent settlement, and the first commensal organisms (which would become very important to humans, like plague carrying rats and domestic dogs, etc.) came on the scene.
  • Agriculture has multiple origins, but a single origin is implied here.
  • The origin of copper metal working happens in multiple places (two with smelting in the old world, plus it was worked in the new world).
  • Similarly, other metal working has multiple origins.
  • People will fight about the date for “proto-indo-european” languages or even is fuch a proto-thing existed or could be dates. The majority of historical linguists don’t accept this at all. But if that is right or not, again, Indo-European languages are not particularly important in overall human history. The cartoon centralizes a relatively rare language group and ignores thousands of other language groups, as though the mostly post hoc Western lineage of human civilization is assumed to be the most important.
  • “Permanent settlement in the fertile crescent” is out of the blue, and contradicted earlier on the time line. Permanent settlements in the region predate this by 6,000 years.
  • All of the early steps in civilization rising are focused on a very limited area, represent only a small (and very Western oriented) portion of civilization, ignoring most of human prehistory, and privilege “civilization” over what the fast majority of people were doing at the time.
  • Same problem with writing. Writing was invented many times over many areas, but it looks here like it may have a single origin, the origin that is part of the Western Civilization story.
  • Missed opportunity: “Invasion of the sea peoples” may very well have been an example of climate change messing up a population and causing a mass migration.
  • For later civilizations, I appreciate the reference to the New World. But again, it is only part of the story, mentioning a small part of the record. Isn’t it a much more interesting story to note that between 10K and 2K (or so) dozens of independent highly organized hierarchical societies, often referred to as “this or that civilization” arose all over the world, while at the same time, the vast majority of people lived off the land as foragers?
  • The Industrial Revolution starts in the 18th, not 19th,century, in Europe.

Larger scale things you might learn from this graphic that are wrong.

That agriculture was invented once, as part of Western Civilization, and the same for metal working, marginalizes the new world, many regions of Asia, many regions of Africa. These are misconceptions that those of us who teach intro to world prehistory or similar courses have to spend a large amount of our time refuting.

The idea seems to be represented that humans made the transition from hunter-gatherers at one point in time and thereafter were mostly agriculturalists. The opposite is true. Most humans were living in small groups as hunter gatherers for the entire time represented by this cartoon, except at the end. Half the humans or more at the time of Christ, for example. It is likely that in many regions, at various points in time, an early stab at horticulture was abandoned, and people returned to agriculture.

Is this important?

Well, getting facts right is important. In the case of prehistory, this mainly means not overstating the facts. One might argue that in a simplified version of reality (like in a cartoon) it is ok to overstate things as facts where we really don’t know. No, it isn’t. There are ways to speak briefly, and in an interesting way, of a past that we understand more vaguely than some DK book for five year olds. So let’s do that.

The oversimplification of prehistory contributes to the co-opting of intelligence, innovation, rights over various things like landscapes and cultural phenomena, by the dominant cultures who have condensed the relevant prehistories to centralize and privilege themselves. The prehistory presented here mostly privilages what we sometimes refer to as “Western Civilization” with its middle eastern roots and its simple, linear, one way, always improving, progressive history. A very inaccurate history.

As Helga Vierlich wrote on my Facebook timeline, “In short, this reflects a preoccupation with “progress” whereas what it really shows is a progressive ecosystem and social clusterfuck that brings us to the present situation – characterized by continuing destruction of the last ecologically sustainable (“indigenous”) economies… and also characterized by deforestation, massive climate change, pollution, ecosystem distraction, soil erosion, and species extinction.”

So, in making a point about self destruction by the human species, due to anthropogenic climate change, the oversimplification misses key points in that actual process.

But it is still a good cartoon.

I would like people who pass this cartoon around to make a brief statement, like, “I hear the prehistory is oversimplified a bit, but this makes a great point about climate change” or words to that effect. Many will argue that this statement is not enough. But I’m not a big fan of sacrificing the really cool for the sake of the perfectly pedantical. Usually.

Micro-Evolution In Greenland: Inuit Diet, Weight, and Stature

There is a new paper in Science linking genetic variation in people living in Greenland with long term selection for managing a marine-oriented diet, affecting stature, weight, and probably, physiological processing of omega-3 polyunsaturated fatty acids (PUFAs).

The vast majority of the variation we seen in stature (height) among humans is not genetic. That is a fact hard to swallow by so many of us who were told in biology class that “height is a complex genetic trait with many genes affecting it.” It also seems wrong because the classic examples of variation in stature, the Pygmies of Central Africa (short) and the Maasai of East Africa (tall) are assumed to be populations under selection that caused them to be outliers. Of course, the Maasai are really not that tall by modern Western standards, but the story about them being tall, first told by relatively short European travelers who met them in the 19th century, persists, despite the fact that those travelers’ offspring, such as Modern Americans and Brits, are in many cases significantly taller than their own ancestors without natural selection being the cause.

But there are some genetic factors that control height and weight and account for some percentage of variation in those phenotypes. Pygmies taken from their homeland and raised among people with unlimited food supply do not grow tall. They may become obese, but not tall, because one of the main genes that regulates growth in almost all humans simply does not function in Pygmies. (One individual Efe Pygmy I’ve met who was raised among Italian nuns, in Italy, was short but rather wide.) There may be other short statured populations with a similar genetically determined stature. But as far as we can tell, something like 20% (and that is probably an overestimate) of variation in stature in living humans over the last century or so can be accounted for by genetic variation. The rest is a combination of diet and, I suspect, an epigenetic effect linked to maternal size and diet. When a population of relatively short people get unlimited food the next generation is taller. But then, the next generation is taller still. It is as though mothers won’t give birth to maximally sized offspring, just somewhat larger offspring, who then give birth to somewhat larger offspring, so the part of the demographic transition where everyone gets taller happens over a few generations. This is a well documented but not very well explained phenomenon, and the explanation I suggest here is merely a hypothesis.

A new study in Science looks at the Inuit people, and some Europeans living in the same place they live, in this case Greenland, and finds a genetic component to Inuit stature and weight. There are also other differences having to do with processing elements of their relatively unusual diet.

The key result with respect to weight and height is shown in the graph at the top of the post. The letters (GG, GT, TT) are the alleles (T is the derived allele). Homozygotes for the derived allele are quite a bit less massive, and a small amount shorter, than those without the allele, and heterozygotes are in between.

Here is the abstract from the paper:

The indigenous people of Greenland, the Inuit, have lived for a long time in the extreme conditions of the Arctic, including low annual temperatures, and with a specialized diet rich in protein and fatty acids, particularly omega-3 polyunsaturated fatty acids (PUFAs). A scan of Inuit genomes for signatures of adaptation revealed signals at several loci, with the strongest signal located in a cluster of fatty acid desaturases that determine PUFA levels. The selected alleles are associated with multiple metabolic and anthropometric phenotypes and have large effect sizes for weight and height, with the effect on height replicated in Europeans. By analyzing membrane lipids, we found that the selected alleles modulate fatty acid composition, which may affect the regulation of growth hormones. Thus, the Inuit have genetic and physiological adaptations to a diet rich in PUFAs.

How long have the Inuit been living this lifeway, in this environment? Actually, not that long. The researchers, in their supplemental information, suggest that it could be as long as 30,000 years, but this is unlikely, or at least, the story is more complicated.

There are several complications to understanding the history of the selective environment of the Inuit, the environment that would have shaped this genetic adaptation. First, the environment has changed. Not only have we gone from an ice age to no ice age during this 30,000 year time period, but with sea level rise during the Holocene, the ecology of the arctic has changed considerably. Large areas of the continent have been inundated by the sea. Prior to that, most of the ocean adjoining land was immediately deep. With the inundation of the continent, vast relatively shallow areas of ocean would exist. Nutrients well up along the continental shelf, but shallow areas are also potentially nutrient rich because of sediments coming off shore. During glacial melt periods, there may have been frequent large scale fresh water incursions which would have had occasional disastrous effects on the local ecology. The position of estuarine settings, which can be very productive, would change. As sea level rise slowed, near shore sediments may have had a chance to build up, causing regional increases in productivity.

The migratory patterns, overall distribution, and abundance of marine mammals and common shoaling fish would have changed dramatically, and multiple times, during the last several thousand years. It would not have been until about five thousand years ago that things would have settled down allowing long term regional foraging adaptations to emerge. Prior to that there may have been periods when the marine environment was significantly more, or significantly less, productive.

Meanwhile, the ancestors of the Inuit themselves moved a great deal during this period. They were not in Greenland, or anywhere in North America, 30,000 years ago, but rather, in an unknown location in Asia. The Inuit ancestors were part of a later migration into the New World. The association (population wise) of true Arctic people and others living farther south is not known.

A second factor is cultural adaptation. When we look at the traditional Inuit foraging patterns and associated technology, together with the preceding prehistoric Thule adaptations, we can’t help but to be impressed with the highly specialized effective approaches, both strategically and technologically, to acquiring marine resources. Boats, lamps, harpoons, and processing tools are highly refined and efficient. That material culture and strategic approach, however, is only a few thousand years old. Before that, in the region, were the Dorset, who simply lacked many of these tools. It is possible that the Thule and Inuit had sled and sled dogs, but earlier people in the Arctic did not. And so on. The ancestors of the Inuit, just a few thousand years ago, could not have had as specialized a diet as the traditional (modern ethnohistoric) Inuit. Cultural adaptations changing over time is as important as, if not more important than, the afore mentioned likely changes in environment.

So, I’m not going to argue that these adaptations are not 30,000 years in the making. Rather, I’ll argue that strong selection for these alleles could be as recent a few thousand years or even less, and that prior selective environments (the combination of the natural environment and human cultural adaptations to it) may have different and the situation may have been rather complicated for many years. In other words, the new, and very interesting, results looking at the Inuit genome need to be integrated with a better understanding of Inuit history, which is probably going to require a lot more research in the region.

There is a second point I want to make about this paper. We see research suggesting a genetic explanation for a lot of things, but often, in the past, that has involved finding a correlation between this or that genetic variation and a presumed phenotypic feature. Often, the next key step to establish the link isn’t, perhaps sometimes can’t be, taken. This is the link between the observed genetic variation and a good physiological story. The present research finds genetic variation associated with physiological features that seem to be associated with a marine-oriented diet in an Arctic or Sub Arctic setting. That makes this research really valuable.

Greenlandic Inuit show genetic signatures of diet and climate adaptation
Matteo Fumagalli, Ida Moltke, Niels Grarup, Fernando Racimo, Peter Bjerregaard, Marit E. Jørgensen, Thorfinn S. Korneliussen, Pascale Gerbault, Line Skotte, Allan Linneberg, Cramer Christensen, Ivan Brandslund, Torben Jørgensen, Emilia Huerta-Sánchez, Erik B. Schmidt, Oluf Pedersen, Torben Hansen, Anders Albrechtsen, and Rasmus Nielsen
Science 18 September 2015: 349 (6254), 1343-1347. [DOI:10.1126/science.aab2319]

The Hydraulic Hypothesis and the End of Civilization

OK, I admit the title of this post is possibly a bit extreme but I could not resist the symmetry. Here, I refer to both ends of civilization, the start and the finish.

I’d like to talk about a recent review published in Science, titled “Systems integration for global sustainability” written by my colleague Peter Gleick of the Pacific Institute together with Jiangou Liu, Harold Mooney, Vanessa Hull, Steven Davis, Joane Gaskell, Thomas Hertel, Jane Lubchenco, Karent Seto, Claire Kremen and Shuxin Li. But I want to put this paper in a broader perspective, dipping into my training as an archaeologist. But first a relevant digression.

The so called “Hydraulic Hypothesis” is an idea first fully characterized by the historian Karl Wittfogel. His original idea was part of a larger model for the origin of civilization that we see today as having several problematic aspects, but the key idea is still valid. If agriculture is the basis for a society, and it is carried out in a semi-arid region, then the management of water through various forms of irrigation and the centralized control of the agricultural cycle lends itself to centralized despotic leadership. or at least, some kid of cultural and social change allowing for organized effort to predominate over individual self interest. (In fact irrigation based systems have emerged without despotic leadership, and complex society has emerged absent a hydraulic beginning, so this is an oversimplification, just so you know.) But in its simplest form we can correctly say that the emergence of stratified, hierarchic, complexly organized societies was often linked in no small part to the emergence of organizational (and technological) solutions to growing food where there is not enough rain at the right time of year. There is a great advantage to growing food in this manner. The crops become, in essence, invasive species, because human activity provides the crops with a leg up on all the other plants in the region. A plant that in wild form is found primarily in limited microhabitats, out competed everywhere else by more arid-adapted plants, suddenly has a free ride across a vast landscape. Despite the fact that the Hydraulic Hypothesis is an oversimplification, we can appreciate the fact that the beginnings of human “civilization” (as a social and economic system, which we retain today by and large) is linked partially but importantly to managing water to grow food.

At present the news story that never fails to occupy the front page is ISIS, the Islamic State, making a nuisance of itself in Syria and Iraq. It is generally thought that ISIS emerged in large part because of the quasi-failure of Syria. Syria transited from being a run of the mill Middle Eastern Kingdom with some powerful connections to a quasi-failed state for a number of reasons, but one of the big factors turns out to be water. Or, really, lack thereof. In a recently published paper (not the one in Science mentioned above), Peter Gleick made this point:

The Syrian conflict that began in 2012 has many roots, including long-standing political, religious, and social ideological disputes; economic dislocations from both global and regional factors; and worsening environmental conditions. … key environmental factors include both direct and indirect consequences of water shortages, ineffective watershed management, and the impacts of climate variability and change on regional hydrology. Severe multiyear drought beginning in the mid-2000s, combined with inefficient and often unmodernized irrigation systems and water abstractions by other parties in the eastern Mediterranean, including especially Syria, contributed to the displacement of large populations from rural to urban centers, food insecurity for more than a million people, and increased unemployment—with subsequent effects on political stability. There is some evidence that the recent drought is an early indicator of the climatic changes that are expected for the region, including higher temperature, decreased basin rainfall and runoff, and increased water scarcity. Absent any efforts to address population growth rates, these water-related factors are likely to produce even greater risks of local and regional political instability, unless other mechanisms for reducing water insecurity can be identified and implemented.

Two key graphics from Gleick’s paper demonstrate the role of climate change. First, the drop in available water due to decreased rainfall and, probably, increased evaporation:

Screen Shot 2015-03-02 at 8.22.09 AM

Second, the decrease in annual average discharge of a key river in the region:

Screen Shot 2015-03-02 at 8.23.28 AM

Adaptation to an arid environment allowed the development of agriculture, and required the development of complex states, thousands of years ago, in this region. Subsequent increases and decreases in aridity and other natural climate factors have been recognized as creating local collapses around the Mediterranean during subsequent millennia. But now, climate change (together with the other factors Gleick mentions) has pushed the system over the edge. Thousands of years of technological adaptation and cultural evolution to address the problem of growing grains and orchards in dry country together with modern technology to the extent it has been applied have been insufficient to allow the system to continue in some localities, and everything we know about climate change strongly suggests that this is going to get worse, eventually encompassing the entire region. Expect most of the Middle East to become a client region for global agricultural production over the next decade or two. The term Arab Spring is deeply ironic; the spring is running dry.

So this is how the Hydraulic Hypothesis bookends civilization. Cultural technological management of limited or badly timed natural water were adaptations to semi-arid climate conditions and contributed to the development of what we call civilization. As climate conditions shift to the point where these adaptations become unreliable, the system fails. And, the failure is in part because of prior success. As a highly integrated but organic system it is unable to manage deep and causative change. If Vulcans ran the Earth, the Syrian farmers would have been, logically, put on some sort of dole and eventually retasked, and there would not have been a civil war. But since we rely so much on organic system evolution (which includes in part the much vaunted “free market”) that is not what happened.

The review in Science addresses the large scale system dynamics. From the paper:

Global sustainability challenges, from maintaining biodiversity to providing clean air and water, are closely interconnected yet often separately studied and managed. Systems integration—holistic approaches to integrating various components of coupled human and natural systems—is critical to understand socioeconomic and environmental interconnections and to create sustainability solutions. Recent advances include the development and quantification of integrated frameworks that incorporate ecosystem services, environmental footprints, planetary boundaries, human-nature nexuses, and telecoupling. Although systems integration has led to fundamental discoveries and practical applications, further efforts are needed to incorporate more human and natural components simultaneously, quantify spillover systems and feedbacks, integrate multiple spatial and temporal scales, develop new tools, and translate findings into policy and practice. Such efforts can help address important knowledge gaps, link seemingly unconnected challenges, and inform policy and management decisions.

The study focuses on biofuels and “virtual water” to illustrate the broader concepts. Since we’re talking about Hydraulic adaptation at the beginning and end (maybe) of human civilization, let’s look more closely at the virtual water.

What is virtual water, you ask? Let’s say you and I are the farmers (there are no other farmers) and together we produce all of the food. We live in different places and the food gets traded back and forth. You may be surprised to hear that for every liter of water the people who live in our hypothetical two-farm world drink as refreshment, we farmers require something like 100 liters of water to match that in food (that is a very rough estimate). But the water requirement varies tremendously by the kind of food. Let’s say I grow wheat and you grow eggs. That means that every person-year of food (in terms of calories) that I grow requires a very small fraction of the water that you need to grow one person-year of calories. Plants generally require a fraction of the water that animal products require. Even among plants the differences are rather large.

So, if we trade wheat and eggs (I give you wheat and you give me eggs) evenly by calorie, than we are simultaneously trading water, but very unevenly. When I give you 1000 calories of wheat, I’m giving you something like 1000 liters of water, virtually. When you give me 1000 calories of eggs, you are giving me perhaps a million liters of water, virtually. If you are farming in a water rich region and I’m farming in a water poor region, that makes sense and it may even be the reason I grow wheat and you grow egg chickens. Or, if we started out with plentiful water relative to production in both regions, but your farms experience increasing aridity, there is now a pressure for us to change our virtual water trading practices. You should be growing some wheat and I should be growing some chickens.

Alternatively we could eat less animal product. Or, if you like you can experience a regional civil war in your part of the world and create a religious state that everybody hates. Whatever.

In real life, virtual water is quite complex. From the review:

The main virtual water exporters (sending systems) are water-rich regions in North and South America and Australia, whereas Mexico, Japan, China, and water-poor regions in Europe are the main importers (receiving systems)… Asia recently switched its virtual water imports from North America to South America. On the other hand, North America has engaged in an increased diversification of intraregional water trade while trading with distant countries in Asia. China has undergone a dramatic increase in virtual water imports since 2000, via products such as soybeans from Brazil (nearly doubling from 2001 to 2007 and amounting to 13% of the total global world water trade). The spatial shift in the use of soybean products in Brazil from domestic to international has led to water savings in other countries, but at the cost of deforestation in Brazilian Amazon. Within-country virtual water transfer is also common. For example, virtual water flow through grain trade from North China to South China goes in the opposite direction of real water transfer through large projects, such as the South-to-North Water Transfer Project, that aim to alleviate water shortages in North China.

Or, in the form of a picture, from the review:

Screen Shot 2015-03-02 at 8.51.07 AM

To me one of the key issues raised when taking a system level look, and this refers back directly to the Hydraulic Hypothesis, is the role of regulatory process and government. After all, we created these governments (as part of civilization) for the exact reason of managing the emerging complex system of agriculture (oversimplified again … and there were other reasons of course). So I asked Peter Gleick what he thought about the relationship between free market economics, regulation, and government (or higher level) involvement. He told me, “Free markets are both a solution and a problem. There is growing evidence that for a number of critical global challenges, government oversight and regulatory institutions are critically important to correct the failure of free markets. We encourage trade in goods and services worldwide, which has led to a remarkable trade in “virtual water” — the water required to make those goods and services. This is a good thing, in my opinion, because it permits countries that could never possibly be self sufficient in food because of insufficient water (most of the Middle East and North Africa) to use their limited water for higher valued economic activities and then buy food on the market. But the market failure here is that natural ecosystems do not compete or play a role in such “markets” — permitting the complete extinction of endemic fish from the Aral Sea to grow cotton in the Central Asian republics for export. I could give other examples of gross free market failures with global consequences (ozone hole, climate change). So, yes, balance markets with strong government regulatory oversight to protect public goods.”

This makes sense because of one of the things people almost always forget when it comes to market forces. The free market model assumes that the system is made up of “ideal free actors.” Ideal free does not mean free of ideals! (Maybe there should be a comma there.) The actors in the market are “ideal” in that they are identical in their access to information and ability to act on it, and they are free in the sense that there are no external constraints on those actions. So, ideal actors regulated (not free) do not make up a free market (that is the point usually made by Libertarians) but more often than not, the actors are not “ideal.” It is a major failure of integration of economics theory and social theory to place the non-ideal parts in the category of “external costs” and ignore them. One actor’s external costs is another actor’s non-idealness.

I also asked Gleick to elaborate on the relationship between regional collapse and the global system, as a means of integrating the two studies I cover above. He responded, “… can regional collapses influence or perturb global systems, rather than the other way around? I would argue for example that perturbed global systems are influencing regional collapses (for example, climate, drought, and Syria). A functioning global systems approach would have to be able to handle regional perturbations. Could you argue that the political collapse in the US Congress is a major barrier to a global systems approach to cut greenhouse gas emissions? Yes. But that US government failure can be bypassed by other mechanisms, as we’re seeing now with California’s cap/trade system; collaborative state efforts; federal efforts that bypass congressional constraints using other mechanisms.”

Peter Gleick has written up his own comments on the Science review, on his blog, here.

Citation: Liu, J. H. Mooney, V. Hull, S.J. Davis, J. Gaskell, T.Hertel, J. Lubchenco, K.C. Seto, P.H. Gleick, C. Kremen, S. Li. 2015. Systems Integration for Global Sustainability. Science, Vol. 347, No. 6225. 27 February 2015. DOI: 10.1126/science.1258832

Other posts of interest:

Also of interest: In Search of Sungudogo: A novel of adventure and mystery, set in the Congo.

Greenpeace names names

You’ll recall that a while back, Greenpeace activists entered a restricted zone in Peru, where the Nasca Lines are preserved, and messed with that important archaeological site. I wrote about it here.

At the time, the individuals who had carried out this unthinkable act managed to drift off into obscurity, and Greenpeace seemed unwilling to provide Peruvian authorities with their names.

Now, they have done so. Partially.

From Bloomberg Businessweek:

Greenpeace has provided Peruvian authorities with the identities of the four foreign activists principally responsible for vandalizing the Nazca Lines heritage site during last month’s international climate negotiations in Lima, Bloomberg Businessweek has learned. …

“Lawyers representing Greenpeace are driving from Lima to Nazca now to deliver our report to the Peruvian prosecutor,” Mike Townsley, the chief spokesman for Greenpeace International, said on Monday evening. “We have said from the start that this action was wrong, it was crass, it was insensitive, it shouldn’t have happened, and we would cooperate with Peruvian authorities to set things right.”

The mastermind of the Nazca Lines action was Wolfgang Sadik, a veteran campaigner with Greenpeace Germany, the Greenpeace report reveals. Two of the other three activists named in the report also work for Greenpeace Germany: Martin Kaiser, who was responsible for all of Greenpeace’s actions at the Lima summit, and Isis Wiedemann, Greenpeace’s chief communications officer at the summit. The fourth individual is Mauro Fernandez, a staffer with Greenpeace Argentina who served as an interpreter during the Nazca action. Fernandez told Peruvian television on Sunday night that Sadik had not “fully informed” him regarding the sensitivity of the Nazca site or the illegality of Sadik’s proposed action.

Greenpeace—whose global budget of €300 million and offices in 45 countries have long made it a force that governments and corporations must reckon with—has suffered heavy blows to its reputation, external support, and staff morale. Donors have withdrawn grants, supporters have canceled memberships, and street canvassers have been harassed, Greenpeace USA executive director Annie Leonard wrote in an e-mail earlier this month.

Sadik and his team went ahead with the action even as others in Greenpeace strongly advised him against it, Townsley confirmed. “The decisions were taken by those responsible while they were in Peru. At that point, there was no recourse back to Greenpeace International in Amsterdam or Greenpeace Germany in Hamburg. … Certainly there are many people [within Greenpeace] who think that our internal processes weren’t followed properly and if they had been, this activity would have been caught and stopped.”

Neither Kaiser, Wiedemann nor Fernandez were involved in “the design or the delivery of the Nazca Lines action,” Townsley said, adding that Sadik was “the principal architect and coordinator, and he himself has volunteered that information to the prosecutor.”

The report apparently does not name roughly 20 additional activists from seven countries who helped Sadik and his team place their message…

Women in Prehistory: Who Made the Paleolithic Hand Impressions?

Dean Snow was one of my two advisors in undergraduate school. I have fond memories of all six months of college. But that’s another story. Anyway, several years ago, Dean got wind of the research showing that humans exhibit sexual dimorphism in the ratios of the middle digits of the hand. It is believed that this is accounted for by differential rates of bone growth during early development that happen to be different, on average, between males and females. There is probably not an adaptive explanation for this. Rather, at some important developmental stage there is an endocrine effect on bone growth that happens to leave a signal we can use to tell males from females, to a certain degree.

Some of this research has gone so far as to suggest that the degree of differentiation relates to other behavioral traits. My favorite is the idea that among men, high level athletes have a higher ratio of finger length difference for the middle fingers than average men. Gay men, on the other hand, have even higher ratios. Therefore all athletes are gay. I won’t bother giving you references for that work because I’m not interested in defending it or even suggesting it is true. I simply choose to believe it, for fun. Let the Evolutionary Psychologists work out the details.

Regardless of any behavioral links, this sexually dimorphic trait could be used to sex individuals. (That term “sex individuals” is a quaint way archaeologists say “determine the chromosomal sex of individuals using proxy methods such as brow ridges and stuff, like they do on the TV show Bones.”) Dean’s idea is this: If finger length ratio is sexually dimorphic, then we could potentially sex the wall hand stencils found in prehistoric contexts as part of the panoply of paleolithic cave art.

It has generally been assumed that males made the wall art. Why? Because we generally assume that males did anything cool in the Palaeolithic. Why? Because Palaeolithic Archaeology, and many other forms of archaeology, has traditionally involved men communing with each other across the ages using things like phallus symbols and hands. Like this:

A phallus in the hand is worth ... oh, never mind.
A phallus in the hand is worth … oh, never mind.

The thing is, there are good reasons to believe that it is not true that females never did anything, ever. Females don’t do nothing ever these days, why would that have been the case in the Palaeolithic? Also, think about the origin and evolution of technology. Chimps use a lot of technology. Virtually all chimp technology is used by females, invented by females, passed from female to female, and so on. Males don’t seem to do any of that. Well, now and then a male is seen to wave a stick around, and one male chimp once picked up an empty gasoline can and waved it around. Publications ensued. But really, the chimp-human ancestor, almost certainly more chimp-like than human-like, probably used some technologies. If I had to guess, I’d say that the earliest chipped stone tools, the Oldowan and related industries, were made by females. These early tools were likely used to access embedded resources, and it is embedded resources we see chimp females (not males) access with technology.

Later, when our ancestors invented phallus shaped tools like spear points, perhaps males took over those technologies. Indeed, I would not be too uncomfortable with the hypothesis that the seminal spear points were a guy thing.

It is also true that men don’t have a monopoly on art. Across the world we see art as an embedded part of cultures, and whether females or males engage in that activity varies a great deal. It might even be the case that among traditional substance or foraging groups females do more art than males. It is probably worth pointing out that one of the best places for art to show up is on cloth, or as part of the manufacture of cloth from fibers, bark, etc. We know from ethnography that this is more a female thing than a male thing. We also know that much of that material is not preserved, and it takes a great deal of effort to access that very important area of culture in prehistoric contexts. Anyway, if art is related to textile and related technology, than we can be pretty sure that early modern human females were doing art. If technology was invented by female chimp-like ancestors of humans than we can be pretty sure that females were involved in that too. In fact, the question we should be asking is this: When in prehistory did males start to do something interesting?

So, back to the wall stencils, like these:

If we can sex hands by measuring digit length ratio, maybe we can tell if these hands are those of women or men. Here’s Dean Snow talking about that prospect:

The people who I know that study the behavioral implications of digit ratios tend to use x-rays of the hand in order to get near perfect measurements of the bones. This cuts out some of the variation that make the process difficult. The actual distribution of ratios between males and females overlap a great deal. Here’s a typical graph showing the distribution of measurements modeled as normal distributions:

Quite a bit of overlap
Quite a bit of overlap

The problem in archaeology is that we are often stuck with data or methods that provide the opposite from the above mentioned x-ray machines. Archaeological data is usually messier than other forms of data. That certainly applies to hand prints on cave walls, which not only show the flesh and not the bones, but they are stencils, which have even less fidelity as indicators of fetal hormonal effects. But, it is certainly worth a look. Also, maybe, just maybe, there is more sexual dimorphism in certain Paleolithic populations which might make the signal more clear. It turns out, that may be the case.

From Sexual Dimorphism in European Upper Paleolithic Cave Art:

Preliminary research on hand stencils found in the Upper Paleolithic cave sites of France and Spain showed that sexual dimorphism in human hands is expressed strongly enough to allow empirical determination of the sexes of the individuals who made some of them. Further research increased the sample of measurable cases from 6 to 32, a large enough sample to show that persons who made hand stencils in the caves were predominantly females. This finding rebuts the traditional assumption that human hand stencils in European parietal art were made by male artists, either adults or subadults. Findings further suggest that the sexual dimorphism of hands was more pronounced during the Upper Paleolithic than it is in modern Europeans. Attempts to apply the same algorithms to a sample of North American Indian handprints confirms the view that different populations require separate analyses.

Other work done by Snow and others suggests that this pattern does not hold across all populations of hands. One would not necessarily expect it to. As usual, further research is needed. In any event, for research on Palaeolithic images on cave walls, this is hands down one of the more interesting results.

Climate Science Deniers Are Annoying Because

It is very hard for me to view the world without my Anthropological glasses, since I’ve been one kind of Anthropologist or another since I was 13 years old. Thinking about climate science deniers, I realized what makes them annoying to me. Let me tell you what I mean.

The ongoing conversation at an archaeological site.
The ongoing conversation at an archaeological site.
When Archaeologists (a kind of Anthropologist, in the tradition I was trained in) dig a site, they are constantly learning about what is under ground at that location, and throughout the process develop a model of what it all means. As an aside I should mention that increasing understanding is not the inevitable outcome. Sometimes more questions are raised than answered. Point is, as more and more earth is moved and more of the structure of the site and its artifactual contents are revealed, the conception among the diggers of what they are working on grows more detailed and often more complex. The archaeologists talk while they work. There will be experts and learners, novices and those with great experience, and as they dig the site speaks to them (a common metaphor in archaeology) and the diggers listen, knowing that what the famous Dr. House always says must not be forgotten: Everybody, including archaeological sites, lies. So at no point do good archaeologists come to a comfortable understanding of what they are uncovering. It is always uncomfortable, shifting, nagging, bothersome, challenging. And most importantly, this process is what archaeology is. The late James Deetz once told me that fieldwork was the most important thing to him and I asked him why. He said, “That’s where I think. I think standing in a hole.” And that is generally true of Archaeology. Archaeologists think standing in a hole, usually in groups, and they talk and between the ongoing results of the digging, the thinking, and the talking, stuff happens in their minds that advances our overall understanding (or complexity of questions about) something in the past. It also feels good. If you are doing that – digging holes in all sorts of weather, spending more time on your knees than a Catholic choir boy, always being dirty but not in a good way, sun burned, tick bitten, knuckle scraped, being mocked by the patch of earth you are busy destroying – and it does not feel good than you should do something else.

So that is what it is like to engage in the process of doing archaeology. Then a car pulls up.

The guy gets out of his car and comes over and asks, “Whatcha doing?” and somebody tells him.

“We’re digging an archaeological site, we’re archaeologists!” an enthusiastic less experienced member of the crew pipes up, walking over to the fence to engage with this member of the public, as we are supposed to do. “It’s an historic site from the early 19th century. There used to be a farm here. We’re tracing out the foundation of the house, and over there, we think we’ve uncovered the place where the farmers butchered their …”

One of the larger round rocks.
One of the larger round rocks.
“I found an artifact,” the interrupting visitor says, interrupting.


“It’s in my trunk, let me get it.”

The archaeologist is left standing at the fence. Sniggers can be heard by some of the more experienced crew members, and glances are passed around like some neat, newly uncovered object might be. There is a reason the least experienced person on the crew was the only one to jaunt over to the fence when the guy showed up.

Returning from his car, holding a huge very smooth ovate river cobble, nearly perfect in symmetry, probably quartzite, “This thing,” hefting it over the fence into the waiting arms of the young archaeologist. “I brought it to the museum but they told me it was just a rock. Obviously they don’t know their rocks! I’ve been running back hoe on construction for years. I know this is not just a rock.”

For some reason, smooth rocks and people who know things have an affinity.

The conversation goes on for a half hour. We learn this guy has been carrying around his rock for over two years, showing it to people now and then. He has a number of theories about what it is, but his preference is to link the rock to Celtic mariners who crossed the Atlantic in olden times and wandered across the continent teaching the hapless Indians how to build stone chambers in which to conduct ceremonies. Despite the fact that this rock is clearly very important, representing a trans-Atlantic connection that only enlightened people accept as true reality, he leaves the rock with the young field worker who promises to bring it to the museum and put in a proper storage drawer where it can be studied by future Archaeologists.

So that was one hour the entire crew can never get back, one hour of failed and eventually forsaken attempts to dissuade the guy of his silly misconceptions, one hour of not thinking about the archaeological site, and also, for reasons of security, one hour during which one or two of the diggers found something interesting but kept quiet about it lest the discovery be drawn into the useless and distracting conversation, or worse, prompt Mr. Backhoe to return over the weekend with his big yellow machine to see what he might find.

That’s what climate science denialists do.

At the moment, and this is probably almost always true, there are some very interesting things going on in climate science. Some of the current issues have to do with the effects of anthropogenic global warming on severe weather. Here’s a brief overview of what is going on.

  • We know warming increases evaporation and thus potentially causes drought.
  • We know warming increases water vapor in the air, which further increases warming (but how much is a matter of debate) and increases the potential for severe rainfall.
  • We know sea surface temperatures are elevated, so when major tropical storms form, they have the potential to be bigger.
  • We know sea levels have gone up and continue to do so, which means that storm surges from various kinds of storms are greater than they otherwise might be.

These effects have something to do with the Drought in California, some major flooding and rainfall events of recent years, and the severity of a handful of major tropical storms including Katrina, Haiyan/Yolanda, and Sandy.

  • For some time science has predicted changes in atmospheric circulation caused by warming that would likely alter major weather patterns. In recent years, this seems to have been observed. So-called “Weather Whiplash” is a phenomenon where the weather in a region goes extreme for a bit longer than it should, then shifts to a different extreme. Drought and flood, heat and cold, that sort of thing. We don’t know but strongly suspect “Weather Whiplash” is caused by global warming’s effects on major air circulation patterns. This is a hot area of research right now, and it is fascinating.

  • We argue about the likely effects of global warming on specific kinds of storms, from temperate tornadoes to tropical hurricanes. Numerous analyses of data and models of climate change have suggested that there may be more of these storms in the future, other studies ‘conclude’ that we can’t be sure, and very few studies show that storms will decrease. The most methodologically questionable studies are the ones that predict decreases in storm overall, though there are a few good studies that suggest that certain tropical regions will experience fewer major cyclones.

That is a rough outline running from greater to lesser certainty. Down there in the lower certainty range there is some interesting science going on. One thing that makes the science especially interesting is the unhappy tension between what climate scientists ideally would like to do and the urgency of understanding what will happen with severe weather in the future. On one hand, climate scientists would like to get a couple of decades of excellent data to supplement older, not as excellent data, to see how climate systems responding to warming reshape our weather patterns. On the other hand, we would ideally like to know now not only if we have to worry about increasingly severe weather, but we’d like to know what kinds of severe weather will occur, when, and where.

That’s interesting. Going back to the analogy of digging an archaeological site, this is like digging a site that is of a familiar type, finding mostly what you expect, but knowing you are adding important data to the overall growing body of information about Early Bronze Age Peloponnesian urban settlement, or New England 19th century farmsteads. But while you are excavating the site you find a stain deep in one corner of a test pit you thought you were about to be done with, and there’s an unexpected artifact in the stain. So you open up a larger area and find a homestead that is not on the map and is not supposed to be there, and as you excavate more and more of it you discover it is loaded with exotic unexpected artifacts and represents human activity that was not known to have occurred at this place and at this time. This would be the most fun you can have with your pants on, kneeling, in the field of archaeology.

And then some guy comes along with his stupid rock and takes you away from it all for an inordinate amount of time. But in climate studies, it is not some guy. It is dozens of denialists, who do appear to be at lest somewhat organized, showing up and doing everything they can think of to interfere with your work. When the scientists get together to discuss the very interesting and important uncertainties, to evaluate very recent work, to share thoughts about the interpretation of newly run models or newly analyzed data sets or newly observed phenomena, they have to spend a certain amount of that time dealing with the denialists. They may even have to spend a certain amount of time talking with lawyers. When they talk to the public or to policy makers they have to spend a certain amount of time, sometimes quite a bit of time, debunking denialist myths and explaining the basic science that should have been accepted as premise a long time ago.

Now imagine once again that you are an archeologist and you and your team have finished work on a major project. You’ve put together a symposium to be part of a major international meeting, at which 9 different papers will be read and discussed addressing various aspects of your findings. You go to the conference. But 2 out of 10 of the people in the room are this guy’s friends. They will insist on asking questions about the Celts and the Giants that once roamed the Earth, and Aliens that mated with earthlings in antiquity to form a race of Lizard People. And they are not polite. Only 2 of 10 in the room come to the conference with these ideas, but they are highly disruptive and control much of the conversation at the symposium, at the bar afterwards, at the airport waiting lounges where people going to and from the conference accidentally run into each other, on the twitter stream spewing from the conference venue.

This is why climate science denialists are so annoying. They are sucking a measurable amount of energy and resources from the process of doing the science and understanding the climate system. Another analogy would be this: Every department of natural resources spending 10% of its budget mitigating against negative effects on Bigfoot, and every news report of anything having to do with parks, hunting, bird conservation, etc. having a Bigfoot spokesperson to address bigfoot issues. When you take climate denialist fueled false balance and re-describe it in any other area of public policy or scientific endeavor, that’s what you get. Bigfoot or something like Bigfoot. Cold Fusion experts always included in any discussion of the Large Hadron Collider, Alien Hunters having equal time after every episode of Neil DeGrasse Tyson’s Cosmos 2014, and so on.

There is plenty of uncertainty at the cutting edge of climate science. There is very little uncertainty at the core. This is because it is centuries old science and the scientists pretty much know what they are doing. Engaging in the false debate is a waste of time and effort, and that, I personally suspect, is the main objective of the denialists. They want to slow down progress, though they may have various different reasons to do so. None of those reasons are valid. They are not Galileo, though they want everyone to think they are. One wonders if they believe that of themselves.

That would be extra annoying.

Photograph of Eliot Park Neighborhood Archaeology Project by Jen Barnett.

Photograph of round rock: zphaze via Compfight cc

Stratigraphy and Site Formation

From Time Team America:

Fort James, South Dakota

In 1865, a unit of cavalry soldiers thought they had volunteered to fight in the Civil War. Instead, they found themselves sent west to keep the peace between incoming pioneer settlers and the Sioux Indians in what is now South Dakota. Upon their arrival, the soldiers built Fort James, one of the few stone forts on the American frontier. The fort’s quartzite walls still peek out from under a grassy field that seems to have somehow survived intact. The site has never been excavated but experts believe that the fort’s remains hold a time capsule of information about life on the early frontier. Time Team America traveled to South Dakota on a rescue mission: to find out how much of the fort survives and how big an area it covers so that the site’s archaeology can be protected for future research.

Time Team America archaeologist Julie Schablitsky explains how archaeologists read the evidence in the layers of soil. Relative dating can establish an older than/younger than chronology.

Watch Reading the Stratigraphy of the Soil on PBS. See more from Time Team America.

Burnt Mounds – Recent archaeological discoveries at Bradford Kaims, Northumberland UK

This video shows some of the remarkable features discovered as part of the Bradford Kaims Wetland Heritage Research Project. The site is located in the ancient prehistoric wetland landscape of Newham bog, near Lucker, Northumberland. This work was carried out by volunteers and students of Bamburgh Research Project, and was funded by the Heritage Lottery Fund and English Heritage. This community archaeology project is open to people of all ages and abilities and we’d like to hear from you if you want to get involved. Please go to the website at www.bamburghresearchproject.co.uk for further details in the ‘Bradford Kaims Wetland Heritage Research Project section and check out the latest updates on our blog: http://bamburghresearchproject.wordpr…

Archaeology Conservation in the Grand Canyon

The National Park Service (NPS) and the Museum of Northern Arizona (MNA) excavated nine archaeological sites along the Colorado River in the Grand Canyon during three years of fieldwork. The NPS/MNA excavation project was the first major archaeological excavation to occur along the river corridor in Grand Canyon in nearly 40 years. The NPS has a “preservation-in-place” mandate, and excavates archaeological sites only when they cannot be stabilized and preserved in place. These sites were disappearing due to erosion; artifacts were literally washing into the river. Because these sites were being lost, the NPS initiated excavations to learn more about the people who lived here before the archaeological evidence of their lives in the canyon was completely gone.

Archaeologists excavated the sites, exposing them for a few days or weeks during which time these videos were taken. Immediately after excavation, the sites were reburied to protect them from further damage from exposure to the elements and possible damage from visitation. This video and the virtual tour (below) is now the only way to experience these places where people once lived.

Archaeology: Holocene Europe

Europe’s Oldest Town?

Bulgarian archaeologists led by Professor Doctor Vasil Nikolov, from the National Archaeology Institute and Museum, claim to have discovered one of the oldest towns in Europe, in north-east Bulgaria.

Dr. Nikolov, who has been studying the area for many years, located the town near the salt pans in the vicinity of Provadia in the Varna Region, the same locale as the first salt factory in Europe.

[Dr. Vasil Nikolov, National Archaeology Institute and Museum]:
“We can now say that the Provadia salt pans are in the oldest town in Europe, existing between 4,700 to 4,200 BC, in the second half of the fifth millennium before Christ.”

Dr. Nikolov says, it was the salt—equivalent in value to today’s oil—which led to the town being established.

[Dr. Vasil Nikolov, National Archaeology Institute and Museum]:
“What makes this ancient village different from all the others in South-East Europe is the salt springs; the salt body is nine meters below us. The salt water was likely evaporated by different techniques in ceramic bowls and the salt produced may have been used as money, because salt was important for humans and animals as well. So salt production made this village different from others, giving it prosperity.”

Further hints of a rich society were found in skeletal remains showing remnants of copper hair accessories.

[Margarita Lyuncheva, Deputy Head, Archaeological Team]:
“There are two graves; probably of people with higher social status, because we found copper spiral needles there, used for hairdressing. We found them where the hair of the buried should have been. We think that the women had their hairstyle in the form of a bun.”

Dr. Nikolov’s discoveries have been confirmed so far by scientists from Japan, Great Britain and Germany, who have closely followed the research connected to the Provadia salt pans.

Mike Morwood Obit

You know about the Hobbit. Not The Hobbit (TM) but the hominid from Flores, Indonesia. Mike Morwood was a key investigator in that research (though he did lots of other research as well).

He was born …

… in Auckland, New Zealand, studied archaeology at the University of Auckland and gained his PhD at the Australian National University in Canberra. From a position in the Queensland Department of Aboriginal and Islander Advancement – the public service body with responsibility at that time for Aboriginal cultural heritage – he joined the University of New England (UNE), in Armidale, New South Wales, in 1981, and worked there until 2007. Mike then moved to the University of Wollongong, also in New South Wales.

In his PhD thesis, on the rock art and archaeology of the Carnarvon Ranges in Central Queensland, Mike had pioneered the inclusion of rock art into other archaeological studies, and continued to work on projects which sought such integration until his death. He turned his UNE course on the archaeology of rock art into the book Visions from the Past (2002).

And there is much more to his bio than that.

In fact, you can read about the “Archaeologist whose discovery of a ‘Hobbit’ skeleton sparked a controversy over human evolution” in this writeup by Iain Davidson, in The Guardian.

Al-Kadada evidence for 5,500 year old human sacrifice

This is a site in the vicinity of Meroe in the Sudan, and seem to date to a period of transition between foraging and farming. From The Telegraph:

In a graveyard in Al-Kadada, north of Khartoum, the archaeologists have dug up the tomb of a man and a woman facing each other in a ditch, with bodies of two women, two goats and a dog buried nearby.

The discovery of the group “confirms” excavations last year which found traces of the oldest human sacrifice ever identified in Africa, Jacques Reinold, a researcher for the French section of the Sudanese antiquities department, said.

What do you think about the interpretations being offered? Do you think that the earliest archaeological evidence of “human sacrifice” is likely to be one of the first instances of such behavior? What are the alternative interpretations of this find?

Photo is of rock art from Tadrart Acacus in Ghat District of western Libya, in the Sahara, part of the UNESCO World Heritage Site, dating to between about 12,000 and 1,900 years ago.