So I’m catching up on my Current Anthropology, and suddenly I’m craving something I never knew existed: tejate, a cold, frothy, corn-and-chocolate drink from Oaxaca, Mexico.
Put it down to a recent brush with a silky, nutty Oaxacan black mole sauce, but suddenly I am really interested in chocolatey Mexican cuisine. I’m also curious because dark tejate sounds like the mysterious twin of horchata, a milky rice-and-cinnamon drink that is my current favorite Mexican refresher.
But tejate may also tell us a story of both caution and hope for globalization, say researchers from the University of California, Santa Barbara. They take issue with the popular notion that global commerce is destined to blend the world’s cuisines into some kind of bologna sandwich of a common denominator. In one of the best opening salvos I’ve seen in a scientific paper, the first line reads:
Leaving out massive fragments of the past to discuss globalization as a unique contemporary event is not only shortsighted but often ethnocentric and limits our understanding….
After all, they point out, Oaxacans in open-air markets were selling something very like tejate when the conquistadors arrived. Globalization may be accelerating, they say, but don’t pretend that trade routes are something new.
Daniela Soleri and her coauthors have staked out a position that isn’t easy to defend. Industrial agriculture has put many small U.S. farmers out of business and replaced the heavenly squishiness of peaches and tomatoes with something more suited to firing out of a cannon. And with the advent of the North American Free Trade Agreement, our prodigious ability to grow corn has flooded Mexican markets with cheap, generic cobs, to the detriment of local varieties that are centuries old.
And in surveys of two Oaxacan villages the researchers did find that more contact with “the outside world” - as measured by literacy rates and proportion of people speaking Spanish versus the local Indian dialect - translated to less tejate consumption, less home-made tejate, and fewer local ingredients used in the brew. Tejate isn’t easy to make (the article includes a recipe), requiring not only corn and cacao but other local ingredients with names like pixtle and cacahoaxochitl, as well as wood ashes.
But here’s the twist: globalization works both ways, invading the villages at the same time it chases local secrets out into the world. As mass-produced corn barges into Mexican neighborhoods, wistful immigrants in Oaxaca city and even Los Angeles create a far-flung demand for the lesser-known varieties. Tejate may be experiencing a downturn in its homeland, but suddenly there’s a market for it in L.A. The researchers found a thriving home-brewed tejate business there that uses pixtle mailed from Oaxaca, maize from a pet-food store, and ashes collected from a local barbecue restaurant.
You can see this agricultural diaspora for yourself at nearly any farmers market: all those Peruvian and Russian fingerling potato varieties, lemon cucumbers and striped beets - all the way to rare triumphs like wasabi root and the infamous durian. (Going a bit farther, the New Yorker recently expounded on a few cherished varieties of medical marijuana.) A pizza restaurant near my home sells handmade El Salvadoran tamales, advertised on a handwritten sheet of spiral-notebook paper taped above the cash register.
As a half-Southern, half-English military brat, I say “Bienvenidos!” My culinary inheritance centers around fried chicken and Marmite sandwiches, and I’m grateful every time I find a good pasilla pepper. I can’t wait till tejate arrives.
I just wonder what it tastes like.
(Image: an Aztec figurine holds a cacao pod; Wikipedia)
Check out this deft rap about life on other planets by Jonathan Chase, a.k.a. Oort Kuiper (yes, that Oort and that Kuiper). The delivery is subdued and literate, like Massive Attack-era Tricky, and the video incorporates clips from Cosmos, the classic PBS series narrated by Carl Sagan. Bonus points for cribbing footage from SETI and working in a cameo by Gregor Mendel.
The bar on science rap has been raised. Once a novelty act confined to late-night grad-school potlucks, where just finding something to rhyme with “plate tectonics” was a triumph; now you get spot-on lyrics backed by leaping basslines and 1950s samples.
Other recent triumphs of the genre include the cogent Large Hadron Rap (405,000 hits in less than a month) and the salt-soaked Cruise, Cruise Baby. Say what you want about the LHR’s backup dancers (I was under the impression that experimental physics required nanosecond-accurate timing) - but I learned more about the setup, mechanics, and ambition of the Large Hadron Collider from this rap than from everything I’ve read on the subject previously put together.
Behavioral ecology, the study of what animals do and how it affects their lives, can be delightfully arcane. One research team designed a robot stickleback in order to learn how many fish it takes to persuade a school to change direction. (Early results suggest the answer is two.)
Another team found that African honeybee workers surreptitiously raise their own eggs rather than those of their queen overlords, in effect staging a bloodless coup.
Mitchell Baker, of Queens College, New York, had some amazing insights into pesticide resistance studying the formidable Colorado potato beetle. “If you leave them alone,” he said, “they will eat a field down to brown sticks.”
A pesticide, like an antibiotic, is supposed to kill any pest that’s not resistant to it. But when survivors get together to breed, one thing they all have to bequeath to their young is pesticide resistance. “Potato beetles can evolve resistance to anything you can throw at them, usually within three generations,” Baker said.
Resistance can have a downside for the beetle, though. It comes with a grab bag of handicaps. Through novel experiments at agricultural fields, Baker discovered that pesticide-resistant beetles hatch later, move more slowly, have compromised immune systems, mate less successfully, raise fewer young, die off during the winter at greater rates, and get cannibalized by their nestmates more often than non-resistant beetles.
Apparently, the genes that make a beetle resistant have such debilitating side-effects that it takes the application of deadly pesticides just for them to survive the competition. Baker’s research could point to ways to postpone widespread resistance by taking advantage of those weaknesses.
It’s tempting to view the world as a collection of species perfectly adapted to living together. But what I find fascinating about evolution are the compromises that constantly play out on any species’ scrap heap of talents. For potato beetles, pesticides are pulling resistance to the top of the pile. But change what’s killing them-a different pesticide, perhaps, or maybe hotter summers-and resistance will fall to the wayside in favor of something equally vital for the moment.
Don’t worry, that’s not a giant bug on the first tomato of summer. It’s a tiny bug on a chile pepper about the size of a caper. But don’t let its size fool you: that’s one of the hottest peppers out there, the chile piquin, which grows wild in Bolivia.
I remember sampling a few of these chiles at a dinner party in Missoula, Montana, some years ago. Scientists describe the taste as “pungent,” which is kind of like calling a bad pinot noir “cheeky” or Henry VIII “irritable.” My recollection goes more like this: a whiff of ozone, a grass fire ripping across my tongue, and then the lingering sensation of pavement that has just been peeled out on by a 17-year-old in his parents’ car.
This week, the host of that party - Joshua Tewksbury, now an assistant professor at the University of Washington - announced a breakthrough in understanding why chiles get so hot. Turns out it has little to do with punishing the taste buds of mammals; nor science’s next best guess, which involved singling out birds to carry the seeds to useful places.
Instead, the chemical warfare seems to be directed at a fungus, called Fusarium, that’s deadly to chile seeds. Spores get into the chiles through holes made by bugs as they feed. (Look closely, and you can see this bug’s straw-like beak plunged between its two front legs and into the chile’s skin.)
Like good scientists, Tewksbury and his research team went to great lengths to test their idea. They sampled wild chiles across 600 square miles of Bolivia. Chiles with more bug-beak holes contained more the spicy chemical capsaicin - and were infected with fungus less often. To clinch the deal, the researchers built imitation chiles and loaded them with differing amounts of capsaicin. Like the real thing, hot fakes were much more resistant to fungal infection.
So chile plants turn up the heat depending on the risk they face from fungi. Could something similar be at work in the evolution of culinary marvels like the four-star panang curry I had for lunch? Did humans start eating fiery foods, back in the days before refrigeration, as a kind of insurance?
At a symposium entitled “Avian CSI” I heard about sophisticated ways that biologists learn intimate details about birds from tiny pieces of recovered evidence. A team of Smithsonian scientists is especially good at identifying bird remains - even mere specks exhumed from the guts of a giant snake.
It turns out that Everglades National Park has a growing demand for experts in snake-meal identification. Wild Burmese pythons, most likely released by fed-up pet owners, have graduated from amusing 10-o’clock-news material into a growing, self-sustaining, and hungry population. Park officials have now captured and killed more than 600 of the snakes. Some contained a full complement of eggs ready for laying.
A host of remarkable birds call the Everglades home, including stunners like the roseate spoonbill, scarlet ibis, reddish egret, and the endangered wood stork and threatened limpkin. And necropsies of captured pythons have turned up plenty of feathers covered in fragrant python digestive slurry. But park officials had no idea which birds they came from. So they turned to Carla Dove and the “feather lab” at the National Museum of Natural History.
To clinch her IDs, Dove uses deceptively low-tech methods that hinge on experience and close observation. There are so many sources of DNA in a python’s stomach that genetic analyses are complicated. Instead, Dove painstakingly cleans feathers and bones, using a fume hood to suck out the most offensive of the smells. Sometimes, she said, she runs down the hall to dry her feathers with the hand dryer in the women’s bathroom.
She puts cleaned feathers under a microscope to analyze their microscopic structure, which differs reliably among different groups of birds. (Here, the distinctive barbules of a common backyard mourning dove.) Dove uses traditional light microscopes instead of electron microscopes because she needs to see into the sample, not just the surface. The final step is to compare python meals with the reference specimens in the Museum’s enormous collection.
So far, the team has identified some 29 species from the bowels of Everglades pythons. Victims include everything from the meatball-sized house wren to the 4-foot tall great blue heron. Rails, coots, and gallinules - slender birds of the marshes - are most frequently eaten, but at least one limpkin and one wood stork have vanished down python throats. One meal even included a magnificent frigatebird, a tropical seabird with a seven-foot wingspan whose closest roosting site is 10 miles away.
The work is fascinating, but Dove says she hopes people think twice before releasing the python they’ve grown tired of into the Everglades. Even so, she says, the population may already be too well established to bring back under control. But the work does point out the way museum collections can yield unexpected dividends.
“A hundred and fifty years ago, when people started this collection,” Dove said, “They could not have imagined the uses we would put these specimens to” - including identifying birds involved in airplane strikes as well as ancient DNA studies. “But they’re crucial to the work we do today. It’s a reminder that we need to continue these collections for purposes we may not have dreamed of yet.”
(Image: Burmese python by Roy Wood, National Park Service; mourning dove feather courtesy Carla Dove)
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