“Why are barns red?” is, apparently, the all-time most popular FAQ at The Barn Journal (sadly, no word on what the second most popular might be).

A few years ago, design writer Steven Heller dedicated his column in Print magazine to this question. It has also been bothering the Chief Architect of Google+, Yonatan Zunger, who published his investigation of the phenomenon yesterday, in a post poetically titled, “How the price of paint is set in the hearts of dying stars.”

Their answers are interesting, and different.

Heller draws on Eric Sloane’s American Barns and Covered Bridges, which explains that until the late eighteenth-century, builders carefully considered a site’s wind, sun, and water exposure in order to position bridges and barns in such a way that the weather would treat the wood:

The right wood in the right place, it was discovered, needed no paint.

By the end of the 1700s, however, farmers began to paint their barns, as “the art of wood seasoning gave way to the art of artificial preservation.” Virginia farmers were, apparently, “the first to become paint-conscious,” although no explanation is given for this shift. Heller does, however, attribute the rise of red, specifically, to both function and fashion.

The red colour came from the addition of iron oxide, which is abundant in the soils of the eastern United States, and is equipped with anti-fungal properties (dissolved rust is still used as a DIY anti-moss treatment today). This new-and-improved red barn gradually superseded its unpainted wooden predecessor, becoming the norm.

Heller concludes, somewhat unconvincingly, that having a nice red barn was also an aesthetic choice, as it “became a fashionable thing that contrasted well with traditional white farmhouses.”

Zunger, on the other hand, starts from the premise that barns are red because red paint is the cheapest. This is certainly not the case anymore — a gallon of barn or fence paint from FarmPaint.com costs $8.95, whether it is grey, green, white, brown, or “traditional barn red.”

IMAGE: Barn paint colours available from AgSpecialty.com

However, red was the cheapest paint, once. According to an article by preservationist Robert Foley (PDF), red was the ubiquitous colour of eighteenth century England and colonial America, produced by mixing iron-oxide rich milled earth with linseed oil and turpentine. The result was called “Spanish Brown,” and, because the precise mineral content of the soil determined the final colour, it could range “from burnt orange through reds and into browns” — “the exact shade didn’t seem to matter, cost did.” Other pigments, such as white lead or verdigris green, required an extensive manufacturing process before they could be mixed with linseed oil and used; dirt could just be dug up and ground.

Zunger is not content to leave matters there, however. Instead, he dives deep into the physics of exploding stars to explain precisely why iron is so abundant in the Earth’s crust, and why ferrous oxide reflects a wavelength of light that is visible to human eyes.

Things get pretty technical, but, in short, “it’s because of the details of nuclear fusion — the particular size at which nuclei stop producing energy — that iron is the most common element heavier than neon.” If you also factor in the temperature of our Sun (and any star stable and long-lasting enough to sustain planets with life on them) as well as the speed at which the outermost electrons in the iron atom spin, Zunger concludes, “iron is going to be, by far, the most plentiful pigment for any species which lives on [sic] a star that isn’t about to blow up.”

Furthermore, in a detail that Zunger actually doesn’t mention, about 2.45 billion years years ago, for reasons scientists don’t fully understand but that seem to be tied to the evolution of photosynthetic cyanobacteria, the Earth experienced something called the “Great Oxidation Event.” Prior to that, oxygen was nearly absent in the atmosphere of early Earth; after that, the iron in ancient soils turned into rust.

So, to sum up: many barns are painted red because paint protects the wood against weathering; because the pigment that went into red (or, more accurately, “Spanish Brown”) paint was the cheapest available two centuries ago, due to the abundance of iron oxide in the soil (due to nuclear physics and blue-green algae) and its ease of preparation for use; and because, despite the fact that green is as cheap as red today, humans tend to display a preference for the familiar.

IMAGE: A white barn photographed by Nyttend, via Wikipedia.

Of course, some barns are white. Whitewash, a mixture of chalk, lime, and water, was also cheap — even cheaper than Spanish Brown in areas with iron-poor soils but readily available limestone deposits left by ancient marine life — and possessed of both antimicrobial properties and sanitary connotations.

IMAGE: The green Sears barn in Newark Valley, NY, via The Barn Journal. It was originally painted yellow.

And some barns are green, but there is no accounting for taste.

At the New York State Department of Conservation’s fyke net in Richmond Creek on Staten Island, nightly glass eel catch totals have tapered off. Further north, in the Bronx River, the annual migration of tiny, translucent baby eels will continue for another couple of weeks. And, in Maine, one of only two states to allow a commercial catch, a few hundred licensed elver fishermen are currently sleeping in their cars, some with guns, in order to defend their nets against poachers, while banks are running low on bills as dealers pay up to $2,000 in cash per pound for their harvest.

IMAGE: Elver migration, photograph by Andrew Fahlund. Glass eels metamorphose into elvers, becoming slightly rounder and darker, once they reach the coast.

This annual eel run is “probably the most miraculous example of migratory evolution on the planet,” according to Chris Bowser, the science education specialist charged with recruiting and running the D.E.C.’s American Eel Research Project. All the way along the East Coast, from South Carolina to Maine, writhing ribbons of these two- to three-inch-long transparent worm-like fish are finding their way into estuaries and up to the freshwater rivers they will call home for up to twenty years. They have made their way to the coast from spawning grounds in the Sargasso Sea (the world’s only sea without a land boundary), just east of Bermuda, in a migratory pattern that is still a scientific mystery.

IMAGE: Glass eels, via.

Eels migrate in precisely the opposite direction to other homing fish species. In other words, while a salmon or shad spends most of its adult life in the sea, returning to the river it was born in to spawn, the American eel is born at sea, floats to the shore on prevailing currents, and chooses its river home seemingly at random, before heading back to its original spawning ground to reproduce and die.

To add to their mystery, most aspects of the eel lifecycle are still unknown to science. As James Prosek, author of Eels: An Exploration, From New Zealand to the Sargasso, of the World’s Most Mysterious Fish, and the director of a new documentary, The Mystery of Eels (which you can watch in full online), explains, no one knows what prompts them to move into freshwater, no one knows how they distribute themselves throughout their range, no one knows what determines their adult gender (although density is correlated to masculinity), and no one has ever witnessed the holy grail of eel research: an adult eel spawning.

Katsumi Tsukamoto, a Japanese scientist featured in Prosek’s film, speculates that the adult aggregate into a large ball and spawn simultaneously, in a sort of eel orgy, but this is pure conjecture — after a lifetime’s research, he has come tantalisingly close, netting fresh eel eggs (which only last 36 hours), but has now had to retire. Chris Bowser added a similar, historical anecdote of eel frustration: apparently, one of Sigmund Freud’s earliest research projects, long before writing The Interpretation of Dreams, was an inconclusive attempt to find the European eel’s gonads.

IMAGE: Pier 15, designed by SHoP architects, and photographed (in low-light with an iPhone, sorry) by me.

Prosek and Bowser (present in, he was keen to stress, an entirely unofficial capacity) had come together to share their enthusiasm for the enigmatic eel at a Sunday-evening meeting of artist Natalie Jeremijenko’s Cross-Species Adventure Club. We met in the future maritime education center building on Pier 15 in Manhattan, a city-funded effort to re-connect New Yorkers to the waters that surround their urban archipelago. Jeremijenko’s own agenda seems, on the surface, similar, but is actually much more radical: the Cross-Species Adventure Club is actually a series of design interaction experiments, intended to transform human relationships with the urban ecosystem into a form of cultivation rather than extraction or damage, or even just straightforward preservation.

“As an environmental mantra, ‘leave no trace,’” Jeremijenko told the assembled Adventurers, “is a bit pathetic. It assumes that we can extract ourselves from our ecosystem — and that we are only capable of negative impact. Can’t we interact with our environment in a way that has a positive effect?”

IMAGE: Cross-Species Adventure Club lures; photograph via Natalie Jeremijenko.

Earlier Cross-Species Adventure Club projects demonstrate ways to put this philosophy into action. For example, Jeremijenko has designed a lure made of gin & tonic-flavoured gellan mixed with chelating agents that remove heavy metals from bio-availability, with the idea that, rather than throwing Doritos and bread at fish in ponds, snacking humans could satisfy their urge to feed fish while also engaging in cumulative acts of environment remediation — and, perhaps most importantly, re-thinking their own place in the urban ecosystem.

This particular Cross-Species Adventure, however, was much less tightly resolved. It began with Chris Bowser describing his fantastic citizen science project, which has been recording baby American eel numbers during the Hudson spring migration since 2008. Volunteers count and weigh each night’s catch at sites along the length of the river, and then release the eels, in some cases further upstream, past any dams or diversions that might have blocked their journey. Although eels are not yet listed as endangered, access to eighty-four percent of the freshwater tributaries on the Atlantic seaboard — the adult eels’ potential homes — has been restricted or cut off altogether.

IMAGE: Images from a report by Chris Bowser’s Hudson River Eel Project (pdf), showing a fyke net, students holding up a bag of elvers and glass eels, and students re-setting the net.

A screening of Prosek’s film then filled in some context on eel science, as well as human/eel relationships around the world (in addition to American eels, there are a number of other species of freshwater eel, or Anguillidae), from eel-worshiping Pacific Islanders to Tokyo eel slaughterhouses capable of cleaning, skewering, and grilling more than 4,000 eels per day.

Indeed, it is the Japanese hunger for eels (they consume more than 130,000 tons each year), combined with the increasing scarcity of their native eel and an E.U. ban on elver export, that has pushed Maine glass eel prices so high. Dealers sell the baby eels to Japanese fish farms, who have worked out how to raise them in captivity to precisely two times the size of a standard bento box, but not how to reproduce them economically, making them dependent on wild-caught seed stock.

IMAGE: Inside a Tokyo eel slaughterhouse. Photograph by David Doubilet for National Geographic.

Educated and fascinated, we were each then given an eel cocktail — or rather, a glass full of glass eels, with a salt water mixer — and asked to consider the question of what a productive human interaction with an eel could be.

IMAGE: With glass eels working out at about $1 each at today’s prices, this was not a cheap cocktail, despite being alcohol free. Photograph by Nicola Twilley.

Jeremijenko had bought half a pound of baby eels from a Maine dealer, diverting them from their sushi fate, and then driven them down to New York City with the intention of offering us the opportunity to release them into the East River.

Bowser was not aware of this plan, and quickly pointed out that not only is it actually illegal to stock fish without a permit, it is also a bad idea: we have no idea what factors made the eels chose Maine, rather than New York, in the first place, and we also don’t know whether they might be carrying any diseases (eel conservationists are increasingly concerned about a swim-bladder parasite that is present in aquaculture operations and has now appeared in the wild).

IMAGE: As part of our eel bonding experience, we were asked to name an eel. This was my attempt. Photograph by Nicola Twilley.

“If you ask me, we should put them in a frying pan with some olive oil and garlic for just a second or two,” Bowser said, describing the taste as “like al dente pasta.” No one seemed to be in a hurry to take him up on this advice, and, instead, for the next hour, we held the eels in our hands (they move constantly, in a way that is ticklish rather than slimy), watched their hearts pump and gills flap inside their translucent bodies, marvelled as they propelled themselves up the sides of the glass, and discussed the various roles of eels and humans in the aquatic food chain.

We learned that baby eels are an important food source for all kinds of other fish, that eels are inveterate cannibals, and that they eat anything that’s too large to inhale using a drilling technique that involves sinking their teeth into the meat and then rotating up to fifteen times per second, until a smaller chunk breaks off. As we became increasingly attached to our tiny eels with their black button eyes, Bowser noted that he wouldn’t recommend keeping an eel as a pet, because “they’re famous escape artists. One day you’ll come home to an empty aquarium and a dead stinky eel hidden somewhere in your apartment.”

IMAGE: A glass eel on a Cross-Species Adventure Club attendee’s hand. Photograph by Nicola Twilley.

IMAGE: Natalie Jeremijenko’s glass eel aquarium. Photograph by Nicola Twilley.

Gradually, we “released” our seven or eight eels into the larger aquarium, and went home, newly enchanted by eels and newly frustrated by our inability to imagine a productive interaction with them. Perhaps that was, in itself, the most productive interaction possible.

Back in 2009, speculative designers Dunne & Raby were commissioned by Design Indaba to think about the problem of feeding nine billion people by 2050.

They looked at United Nations reports predicting that food demand will increase by seventy percent over the next forty years; they considered the arguments of pro-GMO foundations and individuals, who frequently claim that hacking the DNA of food crops in order to make them more productive and nutritious is the only feasible way to meet that challenge; and they noticed that one possible approach was consistently overlooked: the option to modify ourselves, instead.

IMAGE: Foragers, 2009, Dunne & Raby.

As Anthony Dunne explained in a 2010 interview with me, their proposal, Foragers, imagines a scenario in which a group of people “would reject industrial and governmental approaches to food shortages and instead would use DIY synthetic biological processes combined with the spirit of foraging to redesign themselves to different degrees, so that they could digest non-human foods like grass and cellulose and so on.”

Once we defined this group of people that hybridized existing trends, and we knew what the technology would be, we started to explore what would be the most compelling way to visualize it, so that it would be an interesting thing to think about and speculate upon.

We wanted to get people thinking and talking about whether it’s actually worth looking at how we might modify ourselves to increase the range of foods that we can digest, or whether we should limit our focus to different ways of using land or designing plants to produce more food.

IMAGE: Foragers, 2009, Dunne & Raby

Dunne & Raby were quite clear about the intention behind their designs: the project was a thought experiment, designed to provoke people into questioning their assumptions, rather than a collection of working, science-based prototypes.

However, it seems as though science has now caught up with fiction: in a paper published online in the Proceedings of the National Academy of Sciences earlier this week, researchers at Virginia Polytechnic Institute and State University reported on a successful proof-of-concept experiment that used synthetic biology to transform indigestible cellulose into edible starch, in the form of amylose.

The scientists borrowed genes from bacteria, soil fungi, and potatoes and inserted them into E. coli, the workhorse bacteria of synthetic biology, in order to produce the enzymes required to first break down cellulose into smaller components and then reassemble them into starch, in a two-step, one-pot process.

Speaking to Science, one of the researchers described the final product: “No taste in the beginning. After chewing for a while, it tasted slightly sweet.”

IMAGE: From Chun You, Hongge Chen, Suwan Myung, Noppadon Sathitsuksanoh, Hui Ma, Xiao-Zhou Zhang, Jianyong Li, and Y.-H. Percival Zhang, “Enzymatic transformation of nonfood biomass to starch.” The team’s two-step process first breaks cellulose into cellobiose, a compound made from a pair of glucose molecules, and then reassembles it. Between one third to half of the original cellulose can be transformed into amylose; the rest becomes glucose, which can be converted into ethanol for use as a biofuel by yeast.

Despite the final product’s underwhelming sensory profile, the discovery of a process that can render cellulose edible for humans is undeniably exciting: cellulose is the most abundant carbohydrate on Earth.

The paper’s authors, Y.-H. Percival Zhang and Hongge Chen, explain that “the annual resource of cellulosic materials is ∼40 times greater than the starch produced by crops cultivated for food and feed,” and that “every ton of cereals harvested is usually accompanied by the production of two to three tons of cellulose-rich crop residues,” most of which are currently burned or left in place (where they protect and improve soil). What’s more, perennial cellulosic plants don’t require the high-quality land, water, and fertiliser and pesticide inputs of corn, wheat, and soya.

IMAGE: Bales of corn stover (photograph by Wally Wilhelm via Science Daily). Stover, which You, Chen, et al. used as their cellulose source, is often left in place or burned.

No wonder, then, that Zhang and Chen conclude with the claim that “the cost-effective transformation of nonfood cellulose to starch could revolutionize agriculture and reshape the bioeconomy, while maintaining biodiversity, minimizing agriculture’s environmental footprint, and conserving fresh water.”

Extrapolating from the amount of cellulose produced each year, this process could potentially provide up to thirty percent of the extra food the UN’s projections demand by 2050. Fascinatingly, Zhang credits China’s history of famine as his motivation, explaining to Science that: “Food security has always been the number one question for nearly 5000 years of Chinese history. Without enough food, crises happened and dynasties shifted.”

Zhang is quick to point out that the process is not cost-effective yet, estimating that it would currently cost “about $1 million to turn 200 kilograms of crude cellulose into 20 kilograms of starch, about enough to feed one person’s carbohydrate needs for 80 days.” Nonetheless, they plan to commercialise the process, and with five or ten years’ more research, Zhang tells Science that he could imagine companies doing the same thing for just $40.

IMAGE: Foragers, 2009, Dunne & Raby.

Despite its similarities to Dunne & Raby’s vision of using synthetic biology to expand the category of food plants, Zhang and Chen are careful to explain that they imagine their process being carried out in scaled-up cellulosic biorefineries, rather than personal digestive prosthetics, precisely to avoid the controversy that surrounds genetic modification and DNA hacking:

Because in vitro building blocks cannot duplicate themselves, the large-scale implementation of cellulose-to-starch in future biorefineries would not raise the questions about ethics, biosecurity, and biosafety that are often confronted by in vivo synthetic biology projects.

Beyond the question of where exactly we should intervene in the food chain — whether it’s better to modify ourselves, or our dinner — this difference points to the real dilemma embedded in almost all technological solutions to increase food production: sovereignty.

Dunne & Raby’s future foragers embody a bottom-up approach, independent of corporations and government regulation, and based on an ethos of gathering rather than cultivation; Zhang and Chen’s giant biorefineries simply incorporate woody stems and synthetic lifeforms into the structure of our current industrial agrifood system. Choosing which you find more attractive, as well as which you find more plausible, is something of litmus test.

Roadkill cuisine has been making headlines this spring, after the Montana House of Representatives passed a bill (by 99 votes to 1) that allows the state’s motorists to collect and eat the deer, elk, moose, or antelope that was unlucky enough to get in their way. Apparently, food banks in the state already collect freshly killed wild animals from the highways, clean and dress them, and distribute them to the poor, so Montana HB247 simply legalises common practice.

IMAGE: Screengrab from Marketplace’s interactive roadkill map. In Arizona, the state with the lowest probability of a deer/car collision, “deer and elk carcasses may be salvaged by state officials and used for Mexican wolf food under certain circumstances.”

As demonstrated by an interactive map created by Marketplace, several states already have similar laws on the books. Florida is the most permissive: according to Marketplace, “If you hit a deer, it’s legal to take it home and do whatever you want with it. You don’t need permission.”

Most states with roadkill bills do require drivers to notify the authorities; for example, in New York state, residents can salvage deer, moose, or bear from the highway, but only if the collision is reported and deemed to be accidental. A handful of other states expressly forbid the collection and consumption of roadkill, including, somewhat counter-intuitively, that well-known home of guns, “freedom,” and feral hogs, Texas.

In some rural counties in Alaska and Vermont, you can even add your name and number to roadkill phone trees: the state game warden will give you a call when there’s a fresh moose or deer “that’s not too smooshed.”

IMAGE: Screengrab from Marketplace’s interactive roadkill map. In West Virgina, the state in which a deer/vehicle collision is most likely, there are an estimated 30,203 of them each year. “If you report the fatality within 12 hours, it’s legal to remove and consume any and all roadkill. There’s even an annual roadkill cook-off.”

IMAGE: Screengrab from Marketplace’s interactive roadkill map. “It is illegal to collect roadkill in California. Salvaged animals should be deposited in a public scientific or educational institution.”

Opinions are sharply divided as to the desirability of eating roadkill.

PETA endorses it, saying that, “If people must eat animal carcasses, roadkill is a superior option to the neatly shrink-wrapped plastic packages of meat in the supermarket.” Fans point out that, as an alternative protein source, roadkill is free, naturally lean, raised without the energy and chemical-intensive inputs of farmed livestock, and avoids waste (though this last point seems moot, as there are several other species that are only too happy to dine on the flattened fauna that humans leave in their wake).

IMAGE: Opossum in Kansas City; photograph by Richard via Wikipedia.

As far as taste goes, Alaskan roadkill aficionados describe moose as “like hamburger, but with more flavour,” and savour the animal’s gelatinous nose, while British conservationist and regular roadkill consumer Jonathan McGowan sang the praises of the UK’s squashed birds and mammals to The Ecologist magazine last year:

I’m a sucker for deer and pheasant though, and I love fox. It’s delicious – like a very lean, sweet tasting pork. Similar to rat actually.

IMAGE: A moose crossing a road in Alaska; photograph by John J. Mosesso via Wikipedia.

However, not everyone is convinced. Critics point to the parasites and worms harboured by wild animals, and even fans admit to finding roadkill more appetising in the winter, when the cold acts as a natural refrigerant, halting decay. And, although pounding chicken or veal cutlets flat before cooking is a well-established technique in the French culinary canon, Marketplace reports that flattening an animal as you kill it does not produce such delicious results:

A deer that’s been slammed by a car might not have all that much edible meat. “Blood will go into that muscle and that meat is no good,” says Nick Bennett, who owns Montana Mobile Meats and processes wild game. Just how much meat you can get out of the roadkill depends on exactly where and how hard you hit it.

IMAGE: Deer near a deer crossing sign, Massachusetts; photo via The Sun Chronicle.

One of the more interesting aspects of the media coverage is discovering just how common car-animal collisions are. A spokeswoman for insurance company State Farm told Marketplace that they estimate “one and a quarter million drivers every year have some sort of altercation with a deer while in their car” in the United States. The Ecologist reports that “The Mammal Society estimates that some 100,000 foxes, 50,000 badgers and between 30,000 and 50,000 deer are killed on UK roads every year.”

IMAGE: Roadkilled deer on Route 170, South Carolina; photo by John O’Neill via Wikipedia.

For retired biology professor Roger M. Knutson, the Michigan-based founder of the International Simmons Society for the study of flattened fauna, this ubiquity speaks to roadkill’s larger importance. In his book, Flattened Fauna: A Field Guide to Common Animals of Roads, Streets, and Highways, he notes that “those (up to now) non-descript spots and blotches of fur, feathers, and scales are the wildlife we see most often, yet nowhere has there been a guide to their identification.”

Knutson’s approach to the thirty-six most common North American roadkill specimens is that of a naturalist (albeit one with his tongue firmly in cheek), rather than a gourmet. As more and more people live in cities and biodiversity shrinks, squashed animals seem to be bucking the trend, rising in numbers — although, as Knutson laments, both historical and current data on roadkill is thin:

At a time when the total world fauna is surely shrinking in both absolute numbers and species complexity, the road fauna is clearly increasing. Before 1900, in the United States, its presence was recorded by only the most fragmentary references to the occasional horse-stomped snake. With the development in the twentieth century of a much elongated road network and dramatically increased traffic speed, the flattened fauna has increased in both species and total numbers.

Knutson cites an early count, in the “1938 classic, Feathers and Fur on the Turnpike,” in which New Englander James Simmons (in whose honour the Simmons Society is named) measured a density of 0.429 dead organisms per mile. A more recent study in Nebraska suggests that roadkill density may since have risen to 4.10 animals per mile. “This means,” Knutson notes, “that a trip of 1,000 miles could be the occasion for seeing, identifying, and even enjoying anywhere from 400 to 4,000 animals.”

IMAGE: The cover of Roger Knutson’s Flattened Fauna, “the definitive guide for the millions of people who seldom see a wild animal that has not been flattened by the dozens of vehicles ahead of them, and baked by the sun to an indistinct fur-, scale-, or feather-covered patty.”

An extremely slim paperback, Flattened Fauna is nonetheless full of gems: Knutson’s sense of humour belies his detailed study of the “remarkable persistence” of muskrats on even the busiest motorways, the unfortunate tendency of cold-blooded snakes to seek large, flat, sun-warmed surfaces at night, and the particular silhouette or “form toward which” each different animal tends, in its two-dimensional afterlife (“genuine dorsi-ventral flattening is uncommon for rabbits,” for example). Indeed, the study of roadkill has a serious use, beyond entertainment value: as biologist Bob Brockie explained to Radio New Zealand’s This Way Up programme a couple of years ago, counting squashed animals on the road provides an excellent guide to shifts in population numbers and migration patterns.

IMAGE: “The challenge,” writes Knutson, “is to distinguish snakes as a group from any of the numerous long, narrow, non-animal objects that litter the highway.” This photocopy, provided in his book, “represents most of the critical features of road snakes,” including its taper and curve (the result of a reflex action). From Flattened Fauna.

Perhaps the most intriguing aspect of both roadkill cuisine and roadkill safaris, however, is what it tells us about the car’s influence on our changing relationship with animals. In Flattened Fauna, Knutsen speculates that “if the road habitat and its major selective pressure — fast-moving vehicles — were to persist,” we might expect to see the emergence of characteristics related to successful highway negotiation. Indeed, though with a certain degree of scepticism, Knutsen quotes Victor B. Sheffer, author of Spires of Form, Glimpses of Evolution, who believes that “hedgehogs have learned genetically, within our century, to run from approaching automobiles instead of curling up in the defensive posture of their pre-auto ancestors.”

As for humans, as Knutson notes, many of us will drive at least two hundred miles, passing anything from five to twenty-five squashed animals, for every mile we walk in the natural world, observing live animals. Given our lifestyles, it seems only logical that we learn to extend our appreciation of animals to their two-dimensional forms — with, of course, the help of his book, “which is devoted to making the experience of seeing dead animals on the road meaningful, even enjoyable.”

IMAGE: The badger, “the largest, flattest creature to be found on the road,” is here compared to a standard road marking for ease of identification. From Flattened Fauna.

Meanwhile, having domesticated both ourselves and our food supply, we could perhaps argue that the underground popularity of roadkill cuisine is a technologically enhanced resurgence of our inner hunter-gatherers — even if the hunting is being done, for the most part, from the leather seats of a four-wheel drive. Although Montana’s new law has apparently been written to discourage intentional collisions, examples have been reported of roadkill poachers, who, rather than using a bow and arrow or gun, simply put a jam sandwich or sausage roll on the road as bait, and then lie low waiting for a passing vehicle to kill their dinner for them.

Hours of study have been devoted to understanding the ways in which cars have reshaped the built environment, our perception of space and time, and even the global atmosphere; perhaps roadkill provides a small, easily overlooked example of some of the ways they have also redesigned our relationship with the animal world?

From inner-city food deserts to car-centric suburbs, aspects of the physical environment are frequently cited as a contributing factor to the rise of obesity in the developed world. However, new research, published earlier this year in the International Journal of Obesity and summarised online at the Public Library of Science (PLOS) blog, Obesity Panacea, found a surprising correlation between elevation and obesity in the United States.

IMAGE: Above, a topographical map of the USA, from the USGS National Elevation Dataset; below, a Centers for Disease Control map showing age-adjusted obesity prevalence by county.

As the paper’s lead author, Dr. Jameson Voss of the Uniformed Services University of the Health Sciences, points out, mapping obesity prevalence in America reveals distinct, and hitherto unexplained, geographic variations:

Obesity appears most prevalent in the Southeast and Midwest states and less prevalent in the Mountain West. Despite significant research into the environmental determinants of obesity, including the built environment, the explanation for these macrogeographic differences is unclear.

Intriguingly, those areas in which less than a quarter of the population is obese map almost exactly onto the more mountainous regions of the country—the Appalachians, the Rockies, and the Sierra Nevada. And, indeed, after controlling for diet, activity level, smoking, demographics, temperature, and urbanisation, Voss and his colleagues found “a four- to five-fold increase in obesity prevalence at low altitude as compared with the highest altitude category.”

To repeat: Americans who live less than five hundred metres above sea level are more than five times as likely to be obese as their counterparts who live at or above 3,000 metres — even when diet, physical activity, and socio-economic status are all taken into account. Mountain-dwelling Americans, Voss found, weigh in a full 2.4 points lower on the Body Mass Index, on average, than their lowland compatriots.

Voss himself admits to being surprised at the magnitude of the correlation, and he cautions that correlation does not prove causation. However, he does note that a handful of other studies have also demonstrated a link between differences in elevation and body weight.

Among 617 Tibetans, waist circumference, waist-to-hip ratio and BMI were inversely related to elevation, in a range from 1200 to 3700 m above sea level. Similarly, in an endogamous Indian population, women living in the plains were overweight, whereas those living at elevations above 2400 m were of normal weight. Similarly, dogs were found to have lower rates of obesity in the Mountain West than in lower elevation areas of the United States.

He also points out that clinical trials, in addition to observational studies, have shown that hypoxia (due to a reduced oxygen supply, as is the case at altitude) can cause weight loss. Indeed, hypoxia has been demonstrated to induce anorexia in obese rats.

The physiological mechanisms and evolutionary reasons behind this are complex and still somewhat uncertain: Voss speculates that “protection against obesity in hypoxic environments may be biologically adaptive, whereby hypoxia alters the near term survival tradeoff between the benefit of increased energy storage and the cost of excess body weight.”

IMAGE: The Woodmen Sanitorium, complete with individual cabins shaped like teepees to maximise air circulation, Colorado Springs, Colorado. Photograph courtesy the Colorado Springs Pioneers Museum, via The Colorado Springs Gazette.

Of course, this not the first time that topography has been proposed as therapy in the face of an intractable epidemic. Before the discovery of the antibiotic streptomycin, doctors used to prescribe a “mountain cure” for tubercular patients, in the hopes that an extended spell in the clean, cold air would help heal their diseased lungs. In the early twentieth-century, there were seventeen sanatoriums in the Pikes Peak region of the Rocky Mountains alone, to the extent that, in Colorado Springs, according to the director of the local history museum, “Tuberculosis was our industry.”

Given the implications of Voss’s study, it seems as though mountainous regions may be able to promote themselves as health resorts once again, luring in those for whom WeightWatchers, Atkins, and the 5:2 regime have all failed.

Perhaps doctors will offer their morbidly obese patients the option of relocating to Denver or Boulder, in lieu of a gastric bypass. Or, more likely, health insurers, already reeling from the burden of America’s obesity epidemic, will reimburse customers for the installation of a domestic altitude simulation chamber, such as those currently marketed to elite athletes by companies such as Hypoxico, that “allows you to work or sleep at the altitude of your choosing in the comfort of your home.” Meanwhile, during the day, a mask and wheeled hypoxic generator mean that you can bring the mountains with you.

IMAGE: An at-home Hypoxico chamber, adjustable to 3,800 metres of simulated altitude.

The virtual elevation of an entire nation: the next step in anti-obesogenic design?

As most readers of Edible Geography will know, smell makes up to ninety percent of what we perceive as flavour, primarily through a process known as retronasal olfaction, in which odour molecules travel from the mouth to the nose via the throat as we eat.

In other words, we use our noses to smell food after it’s inside us, as well as before. But, in a fascinating snippet of news based on a presentation given yesterday at the American Chemical Society’s annual meeting by German food chemist Dr. Peter Schieberle, it seems that our noses may not be not alone in that ability, and that other cells in our bodies are able to “smell” food too.

IMAGE: Retronasal olfaction illustrated, via this excellent explanation.

Dr. Schieberle’s research is focused on what he calls “sensomics” — identifying and analysing the individual compounds that, in combination, create the flavour of different foods. At the 2011 ACS meeting, for example, Schieberle reported on research showing that, of the more than 600 odour or taste compounds his team had found in chocolate, only twenty-five are “key”; together, they create a chocolate flavour that is indistinguishable from the real, more complex, thing.

IMAGE: Chocolate photographed by André Karwat, via Wikipedia.

But what of the other 575 odour and taste compounds in chocolate, if only twenty-five of them interact with nasal receptors and are experienced as flavour? Do they have any sensory impact, perhaps post-ingestion? In his presentation at this year’s conference, Schieberle explained that he and his colleagues have spent the past couple of years investigating this question, in order to discover “the fate of aroma compounds in the human body.”

Describing one experiment, Schieberle told ACS attendees that when he put “an attractant odorant compound” — some small volatile amides from chocolate — “on one side of a partitioned multi-well chamber, and blood cells on the other side,” the blood cells actually moved toward the odour through chemotaxis. Finally, Schieberle summarised:

Our team recently discovered that blood cells — not only cells in the nose — have odorant receptors. In the nose, these so-called receptors sense substances called odorants and translate them into an aroma that we interpret as pleasing or not pleasing in the brain. But surprisingly, there is growing evidence that also the heart, the lungs and many other non-olfactory organs have these receptors.

This discovery of non-nasal odorant receptors is seeming supported, Discovery News points out, by a 2006 paper in which biotechnologist Ester Feldmesser and colleagues found what they called “widespread expression of olfactory receptor genes” in tissues outside the nose, including the prostate, brain, and colon.

But, as Schieberle went on to ask, does the presence of odorant receptors, and even evidence of their response to particular aromatic molecules, mean that blood cells actually perceive flavour in some way?

Once a food is eaten, its components move from the stomach into the bloodstream. But does this mean that, for instance, the heart ‘smells’ the steak you just ate? We don’t know the answer to that question. [...] But we would like to find out.

IMAGE: Blood cells photographed in a scanning electron microscope by Bruce Wetzel and Harry Schaefer, National Cancer Institute, via Wikipedia.

Moving from science into speculation, it’s tempting to wonder about the possibility of hematogastronomy. For example, just as yoga gurus might learn to consciously experience and control the normally unconscious mechanics of breathing, could gourmets tune into flavour as a whole-body experience — one that starts in the mouth, but spreads throughout the body postprandially?

If so, just as Schieberle already uses his findings on nose-brain flavour perception to optimise chocolate, tweaking fermentation and roasting processes to raise or lower levels of different odour molecules into even more delicious combinations, could chefs or chemists one day spend as much time creating foods that are attractive to our blood cells as to our noses? What is gourmet for blood?

Behold the missing link between Martha Stewart and Moby Dick: the scrimshaw pie multi-tool.

IMAGE: Scrimshaw pie-crimping multi-tools from the collection of the New Bedford Whaling Museum; photograph by Nicola Twilley.

IMAGE: Scrimshaw pie-crimping multi-tools from the collection of the New Bedford Whaling Museum; photograph by Nicola Twilley.

On a recent Venue visit to the New Bedford Whaling Museum, I was captivated by a gallery filled with scrimshaw items, carved by American nineteenth-century whalemen as gifts for mothers, wives, and sweethearts during their long sea voyages. Alongside busks (a rigid insert that kept the corsets straight and upright) and swifts (used to hold hanks of yarn during winding), scrimshanders carved baleen, walrus tusks, and whale teeth into hundreds of thousands of pie crimpers.

IMAGE: Scrimshaw corset busks from the collection of the New Bedford Whaling Museum; photograph by Nicola Twilley.

Serious pastry chefs today still crimp the edges of their pies using their fingers. Some might go as far as using a fork or spoon to create decorative patterns; and the truly gadget-obsessed, or those with no limitations on their kitchen storage space, might even own a simple stainless steel crimping wheel.

IMAGE: Using a fork to crimp a pie edge; photograph by Lauren Weisenthal for Serious Eats.

IMAGE: A contemporary pie crimper from the Chicago Metallic “Baking Essentials” range.

Nineteenth-century scrimshaw pie crimpers, however, are not just useful for sealing pies with an attractive flourish. They incorporate forks for punching air holes, knives for cutting off excess pastry, tart tampers that double as decorative stamps, and, most importantly, two, three, or even four crimping wheels, each of which would imprint a different pattern on your pie crust.

IMAGE: Scrimshaw pie-crimping multi-tools from the collection of the New Bedford Whaling Museum; photograph by Nicola Twilley.

IMAGE: Scrimshaw pie-crimping multi-tools, including one for very tiny pies, from the collection of the New Bedford Whaling Museum; photograph by Nicola Twilley.

The exhibit attributes this functional extravagance to many hours of boredom at sea, but also to the American diet in the nineteenth century. A typical New England meal of the era would involve not just pie, but pies, in both savoury and sweet form. Armed with a crimping multi-tool, a lucky whaler’s spouse or mother need never fear a moment’s confusion differentiating between her cherry and chicken pies.