On June 7th, 2018 we learned about

Identifying the factors that likely enabled humanity’s first attempts at farming

For as influential and beneficial as agriculture has been for the human race, we’re not actually sure why we started farming in the first place. Obviously people would have been happy to have better access to food for their communities, have time for skill specialization, etc., but wanting more food doesn’t explain why people would start farming one year instead of another. Since people started raising crops before they could necessarily write about doing so, researchers have had to start looking at less direct data to figure out what influenced the rise of agriculture. If the resulting models are correct, they not only help eliminate some long-standing hypothesis about the birth of agriculture, but they may be applicable to other questions about early human activities as well.

Making an analytical model

The first step in this research was to look for patterns in the intersections of cultural traits, environmental conditions and population densities in modern or recent foraging societies. Peoples that largely relied on hunting, fishing or gathering to feed themselves were used as verifiable reference point to see what conditions would be expected for a society to carry on without agriculture. Of particular interest were specific factors like environmental stability and how often people traveled in comparison to population density. All these dynamics were assembled into a predictive model that could first be tested against the observed data to ensure that further predictions about ancient populations were grounded in reality.

Researchers then used historical data from around the world to see how environmental conditions could influence a population’s food supply. Agriculture is known to have developed independently at least 12 times in human history around the world, so conditions were analyzed for each of those instances. While many specifics differed, such as the specific year, cultural norms, etc, people from New Guinea to Central America to the Middle East all followed at least one clear trend: their entry into agriculture followed improving environmental conditions.

Predicting more about the past

A possible origin story may have then started with people enjoying enough food stability in their natural environment to have a bit of extra time and population growth. That allowed for more exploration of new ideas or techniques, eventually leading to more revolutionary discoveries like crop cultivation. It seems simple enough, but this possible origin is very different from previously proposed explanations, such as agriculture being the a response to near starvation, or simply arising at random in human history.

The models and analysis that revealed these patterns could likely use further refinement, but researchers are feeling quite confident about their long-term utility. They believe that it could be applied to events further back in time than the 21,000-year-old rise of agriculture, possibly looking at other major developments in human history. By analyzing how humanity changed in response to larger environmental trends, this kind of modeling may help us make sense of otherwise sparse and spotty archaeological evidence.

Source: On the origins of agriculture, researchers uncover new clues by Colorado State University, Science Daily

On April 26th, 2018 we learned about

Deciphering ancient diets from parasite DNA in people’s poop

Hopefully you’re not eating as you read this. If you are, however, future researchers may be able to figure out what you munching on, assuming you had some other organisms enjoying the meal with you. While not as widespread today, many meals can be unknowingly shared with parasitic worms in people’s digestive tracts. Those worms’ eggs are then… deposited in toilets, creating quite the treasure trove of data for researchers. A recent study of various ancient European latrines has even been able to recover DNA from digested food and eggs, adding a new level of detail to our understand of historical diets.

Deciphering dining habits from people’s dung

Researchers dug through toilets from the Middle East to Scandinavia, spanning not just geography, but time periods as well. From the 2500-year-old samples from Bahrain to more recent, 300-year-old poop from the Netherlands, they found that the majority of the parasitic eggs came from species that were transmitted directly between humans, such as pinworms. This wasn’t a huge surprise, as these parasites have specifically evolved to be easily passed between one person’s… unwashed hands to food very easily.

Knowing that people were in contact with other people wasn’t a huge insight, of course. More revealing was the number of eggs from parasites that don’t specialize in human infections. It’s suspected that these eggs were more likely picked up from eating under-cooked pork and fish that had been carrying parasites when they were alive. DNA tests also found revealed the non-worm portions of people’s meals, which generally supported notions of geographic trends in cuisine. For instance, cabbage and buckwheat turned up in northern Europe, while fin whales were apparently on the menu in medieval Denmark.

Tracking worms’ travel between towns

This isn’t the first study to dig through ancient people’s poop to identify components of their diets, but the use of so-called ‘shotgun’ DNA sequencing may open up new avenues of research. In many samples, the mitochondrial DNA was recovered from parasites’ eggs, in addition the nuclear DNA. Because mitochondrial DNA is (almost) only inherited from an organism’s mother, it can be used to trace specific family relationships over time. This means that researchers may soon be able to not only find parasites, but map out how and when they spread from one town to another. This can then help us understand a how people traveled long before they could meticulously document every moment and meal themselves.

Source: Parasite eggs from ancient latrines hint at people's past diets by Public Library of Science, Phys.org

On February 28th, 2018 we learned about

Revising the histories of domesticated rabbits and horses

Humans have apparently domesticated so many animals that we can barely keep track of our activity. A lot of work has gone into trying to uncover the origins of domesticated cats and dogs, and while there’s sometimes contention over new discoveries, we seem to be honing in on how these animals came to live with us. The histories of a few other animals have a bit more room for improvement, as some commonly accepted explanations for how they were domesticated have recently been discovered to just be wrong. In the case of rabbits, researchers are essentially abandoning the notion of a single date for domestication, while horses have recently been found to be entirely domesticated, meaning that truly wild horses have been extinct for ages.

Rabbits’ gradual shift from meat and pelts to pets

Rabbits were supposedly domesticated in 600 AD, when Pope Gregory endorsed raising them so their fetuses could be eaten as a meat substitute during lent. Not only do we lack evidence that such decree was ever issued, but genetic analysis has found that people were probably raising rabbits well before that date. Once the original timing had been disproved, researchers realized that the notion of a single moment of domestication didn’t hold much water either. They said it’s more likely that rabbits were first rounded up as far back as ancient Rome, and then diverged genetically over a long time in their human-imposed isolation. The domestication was a just a gradual byproduct of other needs being met.

Earliest domestication of Equus

Rounding up wild horses was possibly a more deliberate act. When the Botai people of Kazakhstan started rounding up and keeping horses 5,500 years ago, they initiated a change in the horses and their own lifestyles. Archaeological evidence of skulls, fencing, horse-skin leather and an unusual concentration of compounds found in manure suggests that the Botai people gave up being nomads around this time in order to raise horses in permanent settlements. The horses were probably ridden, but also used as a source of meat and milk, not unlike the dietary traditions of some Mongolian tribes today.

Tamed, but then untethered

The Botai were quite successful with their horses, and it’s now thought that some escaped and began spreading across Asia and into Europe. In fact, genetic analysis of living and extinct horses has found that all horses alive today stem from the domesticated Botai horses, including Przewalski’s horse, a sub-species previously thought to be the last wild horse on Earth. Like the mustangs of North America, Przewalski’s horses are actually domesticated horses that have been allowed to become feral. Since their genes have, at some point in history, been manipulated by human intervention, we’re basically left with no horses created strictly by natural selection.

It’s understandable that these mistakes were made. Przewalski’s horse in particular is known for their upright manes, dun-colored coats and other features that resemble extinct wild horses, as well as the wild horses recorded in cave paintings by Neanderthals in France and Spain. Unfortunately, since humans weren’t really aware of how far domesticated horses had spread, it’s hard to say at this point when the last wild horse went extinct. There’s still a lot of biodiversity in domesticated horse populations, but it seems like it would be helpful for humans to fully understand our influences on the world around us.

Source: Surprising new study redraws family tree of domesticated and 'wild' horses by University of Kansas, Phys.org

On February 22nd, 2018 we learned about

New timeline means that Europe’s earliest painters were Neanderthals, not humans

When the cave of Altamira was first discovered in Spain in 1880, it sparked a controversy over the capabilities of primitive humans. The caves had been essentially sealed for tens of thousands of years, and yet were covered in remarkably sophisticated paintings of people, animals and abstract shapes. Some people found it unthinkable that this kind work could have been accomplished by primitive humans, leading some skeptics to claim the paintings were a hoax. An recent examination of the nearby La Pasiega caves is proving those nay-sayers were half-right, but not for reasons they’d be happy to hear. New research has confirmed that the paintings were not made by early humans, because they must have been created by even earlier Neanderthals instead, 64,000 years ago.

Dated by decay

The paintings in La Pasiega, as well as similar caves found in Maltravieso and Ardales, were originally dated based on the decay of carbon 14 atoms. By measuring the amount of carbon-14 isotopes still found in organic matter and comparing that to the known rate of decay, or half-life, of these atoms, researchers can estimate how old an object is. This method is fairly reliable in some scenarios, but it does have its limitations. In this case, a significant issue is that after 50,000 years, so much carbon-14 has decayed that its hard to detect the remaining isotope in any given sample. Since the La Pasiega paintings are now known to be at least 64,000 years old, it’s easy to see how the previous attempts to arrive at an age ran into problems.

This latest investigation then dated the cave paintings using uranium-thorium dating. Rather than sample the paint directly, this method looks at the amount of uranium and thorium found in the carbonate that has built up over time at a given location. The amount of each product of the uranium’s radioactive decay can then provide an age for that speck of carbonate, which therefore provides the latest possible age of whatever the carbonate is sitting on. So by dating the carbonate that’s naturally accumulated on the paint, we now have a more credible age for the creation of the cave’s artwork.

Advanced cultural capabilities

The technique to date the cave paintings is obviously less surprising than the new estimated age of the paintings themselves. We’re confident that humans didn’t arrive in Spain, or any of Europe, before 40,000 years ago. So with these paintings firmly predating the arrival of Homo sapiens, it seems that our species’ only role in this artwork was discovering it. The only other candidates for their creation are Neanderthals, a species of hominid that seems more sophisticated with every new archaeological discovery we make.

This is a big jump in our understanding of Neanderthals’ cognition and culture. The steps required to develop paint as a tool, pick a location to paint, then represent images of the natural and abstract world represent a variety of achievements. Most importantly, recording images for their symbolic, rather than practical, value shows that Neanderthals were able to transmit their culture in a way we had previously thought to be the invention of humans.

This isn’t to say that humans weren’t culturally innovative. Artifacts estimated to be 70,000-years-old have been found in Africa, showing that Homo sapiens has long been a creative species as well. However, the Spanish cave paintings show that Neanderthals weren’t trailing far behind our species in their development. Researchers now want to investigate other European cave paintings in case they were made by Neanderthal hands as well.


My five-year-old asked: How did they make their paints?

The caves were only painted in reds and blacks. The black was from charcoal, most likely retrieved from a fire, and the red was made of pigments like ochre. The painters probably started by crushing the minerals into a fine powder, then moistening them with water or oil to make them spreadable on the stone walls of the cave.

Source: Neanderthals were artistic like modern humans, study indicates by Andrew White, Phys.org

On February 7th, 2018 we learned about

Lasers let archaeologists map miles of Mayan civilization in mere minutes

It turns out the easiest way to map an ancient Mayan city is by blasting the jungle with lasers. Traditionally, the thick canopy of the jungle would require archaeologists to find ancient structures on foot, creeping through the thick, mosquito-infested forests one step at a time. Airplane-mounted lasers are changing all that, effectively clearing out every tree and shrub that may have obscured the view of everything from irrigation ditches to hidden pyramids. Mapping that would have once taken months can now be done in less than an hour, and is understandably being hailed as a “game-changer” for archaeologists.

Looking under the trees with lasers

Importantly, these lasers aren’t actually removing any of the flora or fauna from the Guatemalan countryside. Rather than physically burning away trees, the Light Detection and Ranging (LiDAR) lasers shoot harmless pulses of light hundreds of times per second. Those might be absorbed by whatever they hit, but enough reflect back to the plane to measure the time and therefore distance they traveled. Like a light-based version of a bat’s echolocation, this allows a computer to build a detailed, three-dimensional view of the terrain below.

By firing different wavelengths of light, LiDAR can also detect what kind of materials the laser pulses are hitting. For example, a green, translucent leaf will scatter and absorb high-frequency photons differently than low-frequency photons, which can then be used to infer when a laser is hitting a leaf versus a stone. Combined with taking measurements from multiple angles in the airplane, a LiDAR map can then remove all the organic growth of the jungle, leaving behind a representation of the buildings and walls that were built by the Mayans over 2000 years ago.

New maps of Mayan engineering

LiDAR mapping has already yielded new advances in our picture of Mayan culture. So far, over 770 square miles of the Guatemalan jungle have been mapped, leading to the discovery of 60,000 Mayan structures. Aside from the sheer volume of new buildings to investigate, these surveys have also revealed new types of Mayan construction. While the Mayans were known to farm, advanced agricultural technology has been revealed, including extensive irrigation canals. Additionally, defensive structures like walls and watchtowers have been found, suggesting more advanced levels of warfare in Mayan society than had previously been appreciated. As more of these pieces of engineering are found, the overall picture of the ancient Mayans is becoming much richer than the sum of its parts. Or at least the parts that people had had time to map out on foot.

Source: 'Game Changer': Maya Cities Unearthed In Guatemala Forest Using Lasers by Merrit Kennedy, NPR

On February 1st, 2018 we learned about

Some of the first industrial-scale metalworking was made in Medieval India

You’ve probably never tried it at home, but distilling zinc isn’t easy. Heating zinc to its 1675° Fahrenheit melting point doesn’t give you a nice, pure liquid, but a reactive gas. In a standard furnace, you can expect that gas to rise into the air where it will immediately bond with any available oxygen, leaving you zinc-oxide instead of the metal you were after. It’s no surprise that the first patent on this process didn’t arrive until the 18th century in England. Except for the fact that this process was already in use on an industrial scale in India nearly a thousand years before that.

Treatises dated to the first millennium AD have been found that describe a process to handle the tricky process of distilling zinc ore. A ceramic container, combined with water and organic materials, was heated over a simple charcoal fire. With no widely known labels for lab equipment available, the manual describes the ceramic container as looking like an eggplant, and the vessel that would collect the distilled zinc as a thorn apple flower.

Distilling zinc on a massive scale

Proving that the method described was put into practice, archaeological evidence has found that it was scaled up significantly by the 14th century. Near a zinc mine in the Aravalli Hills of Rajasthan, seven furnaces have been found, each containing 36 of the eggplant-shaped containers. At full strength, this would have produced around 55 pounds of distilled zinc a day. Other furnaces dated to the 16th century show continued innovation, with 108 larger vessels that probably produced closer to 110 pounds of zinc a day.

If those numbers weren’t impressive on their own, the craftsmanship of the furnaces and other components indicate that this was a sophisticated, well-managed foundry. While earlier furnaces look hand-made, later models have uniform parts throughout. It’s presumed that the operation of these facilities would have required coordination between many different parties, all the way to the Maharajah himself.

So what made that zinc worth the invention of industrial chemistry? Northern India lacked tin for the most part, which meant that people couldn’t harden their copper into bronze. However, large amounts of zinc allowed for the production of brass. Brass, which can have a yellow color and luster similar to gold, was apparently used for a variety of purposes. Brass artifacts from the Medieval India range from coins, jewelry, utensils, statues and religious icons. Unfortunately, the advanced distillation procedures that enabled much of this production was largely lost after the Mughals invaded India. Eventually, this squashed local production so much that zinc was imported from China and finally after the 18th century, Europe.

Source: The origins of chemical industry by Paul Craddock, Chemistry World

On November 21st, 2017 we learned about

Ancient Romans sought out citrus fruit as status symbols more than food

How much would you pay for a fruit that’s mostly rind, doesn’t taste good, and can make you vomit if you eat too much of it? If you were a citizen of ancient Rome, probably a lot. Citrus fruit, originating in east Asia, was hard to come by in the Mediterranean two thousand years ago, and so even something as difficult to enjoy as citron (Citrus medica) made a big impression on people. While most of us would pass over less appealing options like citron in favor of a lime or mandarin orange, Roman elites worked hard to appreciate them, largely thanks to citrus’ scarcity in that part of the world.

If you’ve never eaten a citron yourself, you don’t worry too much. Compared to other citrus fruits, citron are nearly entirely rind, leaving little fruit or meat to eat fresh. Some recipes capitalize on this by cooking with the rind itself, such as pickling it in brine before coating it in sugar to make a candy. Thanks to citrus’ hallmark tricarboxylic, aka citric, acid, the Romans enjoyed citron’s striking scent, both as a breath freshener and moth-repellent in clothing. Some citron was certainly eaten, although consuming the fruit was also tied to the ‘medicinal’ purpose of helping someone vomit up toxins if deemed necessary.

Fruit worth flaunting

There was one more good reason to avoid eating one’s citron fruit, which is the need to display it. Citrons, followed later by lemons, were most prized just because they were hard to come by. They were exotic goods imported through Persia, and owning them was a mark of a family’s wealth. They have been depicted in mosaics and even on coins, and seeds have been discovered in the ruins of wealthier villas around the Mediterranean. Citrus was a great food to have in your home, at least until everyone could have it.

As technology and trade routes modernized, Muslim traders made more citrus fruit available to the western world. However, sour oranges, limes and pomelos just didn’t have the same cache, possibly thanks to this increased availability. Food that was accessible to more people wasn’t worth putting on coins anymore, even if it was probably more worthy of a spot on your plate. As petty as that sounds, it wouldn’t be the last time wealthier people abandoned tasty food over its social status. By the time sweet oranges arrived in Europe in the 15th century, citrus fruits weren’t turning many heads anymore. To fully complete the cycle, when thin-skinned mandarins arrived in Europe in the 19th century, the clout once commanded by ancient citrons was long gone.

Source: In Ancient Rome, Citrus Fruits Were Status Symbols by Natasha Frost, Atlas Obscura

On October 30th, 2017 we learned about

The unfounded promise of mummy wheat: revitalizing life from long-dead seeds

People usually prefer fresh produce, but Victorian era Europeans once spent enormous resources on getting seeds and plants that were at least 3,000 years old. The seeds didn’t taste better, nor did they offer any proven nutritional advantages over modern plants. The draw was instead some vaguely insinuated magic that the seeds and plants might posses as a result of having supposedly been entombed alongside mummies. As ancient Egypt filled Europeans’ imagination with thoughts of pharaohs, mummies and magic, any object associated with a tomb was irresistible to collectors. Owning a piece of ancient Egypt, even if it was just a handful of seeds from so-called “mummy wheat,” became a coveted goal that then attracted charlatans and frustrated botanists for years.

Despite the name, mummy wheat was not directly part of the mummification process for dead bodies, not that would have dented some collectors’ enthusiasm. It was simply seeds stored in sealed vases and pots with the intention that the deceased could use it in their next life. The belief was that the afterlife was basically a more idealistic version of one’s actual life, but only if you brought your stuff with you. So alongside jewelry, furniture and even mummified pets, Egyptians planned for their theoretical future by including practical items like beer, seeds and cakes. They probably didn’t plan for how all this would be interpreted by foreigners, or how it might help drive the local economy 3,000 years later.

Desires for prosperity and profit

Unlike other treasures found in ancient tombs, mummy wheat grabbed people’s attention with its mystery and sense of possibility. The seeds themselves were fine, but collectors wanted the seeds to grow and sprout into something bigger. The plants they hoped to grow had great cultural significance, as signs of long dormant power and vitality springing back to life. The wheat was associated with biblical references to Pharaoh’s seven-eared wheat in the book of Genesis. If that weren’t enough, some people also suggested that by sitting in a tomb for thousands of years, the seeds could now yield supernaturally-large harvests. Mummy wheat had something for everyone, which is part of why so many people were selling it.

People who wanted their own magic beans, er, seeds, could sellers near and far. In Egypt, locals responded to tourists’ demand by dumping seeds into ceramic jar, then sealing the lid to give it the appearance of antiquity. Since these seeds were basically fresh, getting a plant to grow wouldn’t be a problem, making for a satisfied customer. If people did get hold of truly ancient seeds, there was probably some pressure to get a plant out of them, giving these wealthy collectors’ gardeners reason to quietly substitute new seeds for the old. For folks who couldn’t make it to Egypt themselves, scam artists were known to even cross the pond, selling Canadians mummy peas for the equivalent of $285 (US) today.

Testing if seeds are dormant, or just dead

Even before this botanical craze started emptying people’s pockets, botanists had suspicions about these ancient seeds. Every controlled study of the seeds failed to grow a plant, and while botanists were convinced they were infertile, the public was slow to listen. Anecdotal success stories, followed by fraudulent seed sales, kept the idea of mummy wheat alive in many people’s minds. The discussion was further distorted by racism, with debunkers often blaming ‘Arabs frauds’ for selling fake seeds while ignoring the role of European scams and sales.

Eventually, as the general fascination with ancient Egypt declined, associations with the seeds shifted from dormant vitality to a symbol of foolishness and gullibility. While some foods entombed with ancient mummies have been found to be safe to eat, there’s no sign that these seeds had any life left in them.

Source: The Myth of Mummy Wheat by Gabriel Moshenska, History Today

On October 29th, 2017 we learned about

Dolphin’s remains found buried in ruins of 14th century building

Humans have been burying our dead for tens of thousands of years. We’ve buried important cats, dogs and other terrestrial animals a bit less frequently. We’ve buried marine mammals like a dolphin… maybe once? It seems obvious why humans would not be preparing graves for dolphins on a regular basis, but archaeologists are scratching their heads as to why someone went to great trouble to do just that hundreds of years ago on an island in the English Channel. Why would a dolphin need to not only be buried on an island, but also in bedrock under a shrine?

The dolphin’s skeleton was discovered among the ruins of a tiny stone-walled building on an island called Chapelle Dom Hue, just 900 feet off the shore of Guernsey. Built on a rocky inlet only 49 feet across, the structure itself may have been a one- or two-room retreat or shrine. There’s not much left of the architecture, but the grave itself is in good shape because it was carved out of the bedrock below the building. Great care seems to have been taken in the undertaking, as the pit has notably squared walls and a flat base.

Deciphering the importance of the dolphin

While the effort and craftsmanship is easily appreciated, archaeologists are struggling to pin down the motivation behind the dolphin’s burial in the first place. No other examples of dolphins being buried in Christian graves have been found, although dolphins are present in Christian symbolism. Once thought to be fish, a dolphin was used as Christian symbol before the crucifix came to prominence. The Greek word for fish, ichthys, was used as an anagram for the phrase “Jesous Christos Theou Yios Soter,” or “Jesus Christ, the Son of God, our Savior.” This connection doesn’t really explain why monks in the 14th century would dig a grave for a dolphin though, which has archaeologists considering a very different explanation for the mammal’s burial.

As well-crafted as the burial bit was, the dolphin’s skeleton looked a bit disarticulated. This supports the possibility that this pit was not a ceremonial grave, but a storage device. While nobody was writing about giving dolphins a proper burial in the 14th century, they did mention eating dolphins as far back as the 13th century. With that in mind, researchers want to examine the bones and soil found at the site for signs that this dolphin had been butchered and was being preserved, possibly submerged in salt. If this proves true, it may also raise questions about the purpose and design of the ruined building. Instead of a private shrine sitting against the sea, it may have simply been a naturally cooled place to cure and store one’s dolphin jerky.

Source: Surprise Find: Dolphin Bones Unearthed in Medieval Island 'Grave' by Tom Metcalfe, Live Science

On September 19th, 2017 we learned about

Speculation about why the ancient Greeks repeatedly rebuilt on earthquake fault lines

Despite what housing prices in the San Francisco Bay area may suggest, most people have an understanding of how dangerous living on an earthquake fault-line can be. It helps that since San Francisco’s historic quake in 1906, a lot of research has been done on what causes earthquakes, leading to more safely engineered buildings that can survive a tremblor. Of course, before people even considered the notion of plate tectonics, seismically active locations have been surprisingly active real estate markets. In fact, there’s a chance that the occasional shake-up actually attracted people, since they interpreted earthquakes as being divine in origin.

Guessing why the ground shakes

Geologist Iain Stewart from the University of Plymouth noticed an odd trend in building locations in ancient Greece, as many cities, temples and monuments were built directly on active fault lines. On it’s own that’s not that odd, but the fact that ancient people’s repeatedly rebuilt ruined structures at these locations indicates that there was a strong motivation to do so. Without scientific explanations and predictions to help shape people’s reactions, Stewart suspects that the ground’s spontaneous movement was likely understood to be an expression of the gods’ will. Even if a building was shaken to dust, knowing that a deity had taken an interest in a particular plot of land boosted its prestige as a sort of ‘holy’ site.

In some cases, the intersection of geology and faith is fairly clear. The famed Oracle of Delphi described visions that foretold the future and explained the actions of the gods. While the accuracy of those interpretations may be up for debate, a biochemical component has been found for the seer’s visions, as ethylene gas was likely produced underground, and released with each bit of seismic activity. The priestess was then probably subject to hallucinations, and would share the her descriptions of these sights as guidance for her visitors. Similarly, an oracle at Perachora Heraion may have lost their divine gift after a quake blocked off a water supply to vision-inducing hot springs in 300 BC.

Picking fault lines on purpose?

Even ignoring these more mind-altering interactions with fissures in the rock, Stewart believes that the ancient Greeks weren’t rebuilding on fault lines at random. It’s hard to move a city to avoid seismic activity, but it should have been possible to a least move a broken temple off a fault. Instead, Stewart things the Greeks rebuilt at the same locations on purpose, possibly to harness the inexplicable energy of that spot. While Stewart has a list of at least four more cities that seem conspicuously located along active fault lines, he admits that he’s looking at this from a geologist’s perspective. He’s hoping that archaeologists will look for evidence of people’s intent to build where the ground shook, helping answer how they rationalized living in such a risk-prone place.

As for the Bay Area… the weather really is lovely most of the year, and the local produce is hard to beat, plate tectonics be damned.

Source: Ancient Greeks May Have Deliberately Built Sacred Sites on Earthquake Faults by John Dyer, Seeker