Tag / food

by Roslyn

Hipsters who hunt

An update on a previous post: my good friends Martin and Vanya are the official poster boys of a new movement.

Collecting oyster mushrooms north of Kingston. Photo by Charlie Croskery.

Read about it here, as told by Vanya’s sister-in-law, Emma Marris. It’s a great article. Charlie took the photos at the Croskery farm (more here). I helped with the shoot, including costume changes and strategic placement of my shadow to avoid lens flare. It was a lot of fun. The only problem is, hipster isn’t the right word for what these guys do. Not sure what would be.

by Roslyn

Chicken of the trees

This month has been an eye-opener for me. Two weeks ago, I was rubbing shoulders with animal rights activists. One week later, I was hunting at the Croskery farm. And last night, we dined on the spoils – a fantastic squirrel stew that gave Thanksgiving dinner a run for its money.

How did it happen?

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by Roslyn

Cultured tastes

Dinner in Shippagan, New Brunswick. Photo by Charlie Croskery.

We drove halfway across the country for the party, but the main course alone was worth the trip. When the pig was finally hauled out by a crew of strapping male relatives, the guests at Anne-Claire and Martin’s wedding converged at the carving table. Small children, I’m told even a Jewish person or two – nobody could resist a taste of warm skin ripped straight off with a knife. Not after seeing (and smelling) the thing turn that entire August afternoon.

I doubt we would have made the cross-country trip if charlem was on the menu. That’s what Vladimir Mironov, an expert in stem cell and tissue science, calls his latest culinary invention. Mironov’s product is grown right in his lab at the Medical University of South Carolina in Charleston – hence the name, short for Charleston engineered meat.

In a handful of labs around the world, scientists like Mironov are working on a curious agricultural problem: how to generate edible meat products without the farm – or the animals1,2. Their solution is to grow meat from animal stem cells. Some use cells taken from embryos, while others, like Mark Post at Eindhoven University in the Netherlands, are looking into the feasibility of growing muscle satellite cells taken from adults1. These can be extracted from domestic pigs or fowl with a quick and painless biopsy, and used to seed in vitro cell cultures.

In the future, this could be an easier way to serve a crowd. Like human cancer cell lines immortalized in a Petri dish, satellite cells can potentially go on multiplying forever in the lab, so long as you give them enough growth medium. Vladimir Mironov sees industry ultimately growing “charlem” – his cultured turkey – in bioreactors the size of football fields that he likes to call “carneries”. He imagines a world where fresh charlem is also grown at your local grocery store, in miniature appliance-size versions of the bioreactor machines3.

His work is, in part, funded by PETA, in an effort to stem the unmeasurable output of animal suffering caused by industrial agriculture. In 2008, the animal rights group also announced their in vitro chicken prize for the first person to develop a commercially viable product and sell it in at least 10 US states. To be eligible, the chicken also has to pass a panel of tasters when breaded and fried. The $1 million dollar reward is still up for grabs3,4.

No doubt this is a noble goal*. Large-scale meat production is an environmental scourge. The North American “meat guzzler”, as Mark Bittman calls it, is not sustainable6. Influential food writers like Bittman and Michael Pollan, and others including star chef David Chang, have been urging us to rethink our eating habits for years7. Environmentally, there’s a lot to be said for the alternatives: we could save a lot of resources by switching to the Asian practice of using small amounts of meat to complement dishes where vegetables and grains are the main event.

According to Nicholas Genovese from Vladimir Mironov’s lab, “Animals require between 3 and 8 pounds of nutrient to make 1 pound of meat. It’s fairly inefficient. Animals consume food and produce waste. Cultured meat doesn’t have a digestive system.”3

He’s right, of course. But his last point also happens to be the very reason charlem will never make it: meat from an animal is more than the sum of its in vitro parts. Want nutrients? We’ll have to add those in at the factory. Vitamin B12 and iron – two of the main nutritional reasons for eating animal protein in the first place – come from gut bacteria and blood1. You can’t get them from muscle tissue in isolation. Want taste? Let me see if we have an additive for that too…

Scientists may figure out how to culture meat efficiently in the lab, but it won’t be a viable solution to our agricultural problems, at least not anytime soon. The trouble with fake meat is that it’s up against evolution on two fronts, and, ironically, morality on a third.

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by Roslyn

To kill bias, gather good data

I hate myself for this: I have the worst sense of direction.

For the entire year when I was living in my first apartment in Kingston, I would take a circuitous route along King Street and then up Princess on my way home from the Kingston Yacht Club. Nearly two kilometers, when walking up West Street would have got me home in half the time. As Charlie said when I revealed this to him, “Two sides of a triangle is always greater than one.”

It’s not that I didn’t know grade school geometry, or that I wanted a more scenic route. I just stuck to the path I knew would get me there.

I felt a bit triumphant when I realized how long it can take Charlie when you ask him to pick up the milk. The last time I dragged him to the grocery store, I left him alone for a few minutes to use the bathroom, and returned to find him loading pineapple after pineapple after pineapple – painfully slowly, into the cart. We laughed, but I don’t ask him to come with me anymore. Alone, I can collect a week’s worth of food in less than 20 minutes.

I’m not ashamed to admit my navigational failings, either. My field assistant Myra and I happily agreed that our best strategy driving around Los Angeles was that we should always do the opposite of whatever we both thought was correct. It worked.

What I hate is my sneaking suspicion that I’m just a lame stereotype. Maybe I’m a terrible navigator because of biology; female brains are just not suited for getting around.

Hunter, gatherer

Modified from this cartoon. Original source unknown.

Recently, psychologists looked at this sex difference in what seemed like a neat field study of human foraging behaviour – in a grocery store1. Joshua New from Yale University, and his coauthors from UC Santa Barbara, set up a unique experiment in a California farmers’ market: they led men and women around the market, giving them samples like apples, fennel, almonds and honey. Then they brought the subjects back to a central location and asked them to point in the direction of those same food items.

These researchers wanted to test the idea that women outperform men at certain kinds of spatial tasks: while men are thought to be better at vector-based navigation, women might excel at remembering the locations of objects, because of the way foraging roles were divided up when our brains were evolving. It’s thought that in our hunter-gatherer past, big game hunting meant that men had to figure out how to bring heavy prey home by the most direct route. Women foraging closer to home needed a much different set of spatial adaptations2. It’s not that men are better at spatial reasoning in general, you just have to choose the right task3.

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by Roslyn

Mind hacks for athletes and the rest of us

For a change of pace, I thought I’d cover two recent neuroscience findings in today’s post. It’s not all academic, either, since both of these studies might help improve your everyday life. Just sit back, suspend your disbelief and fire up the expectation and reward centers of your brain. You might be able to unleash your inner endurance athlete – or epicure, if so inclined – all through the power of the mind.

I’ll start with a surprising finding that I’ve tried to explain to other long-distance runners, who often take a small snack to eat in the middle of a run. I’ve seen the gamut, from orange slices to salty sports drinks and space-age energy gels. The rationale is that these foods quickly replenish the glucose available as blood sugar, the fuel for muscle contraction.

But if you are running for less than an hour, it is biologically impossible for these snacks to improve your performance. For one thing, the amount of carbohydrate that can be effectively absorbed from the stomach to muscle cells in an hour is too small to make any real difference1. And besides, our muscles can hold vast stores of energy in the form glycogen, more than we can possibly use in that span of time, anyway. Spend an hour on a stationary bike, cycling all-out, and you still won’t fully deplete the glycogen in your muscle tissue – so long as you were charged up to begin with2. And yet the snacks work, even in controlled laboratory tests of exercise performance3. No wonder athletes everywhere continue to use them.

Incredibly, this energy boost has nothing to do with caloric consumption, and everything to do with the act of eating.

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by Roslyn

You are what you feed

What makes you you?

The problem of identity – and its flip-side, change – has been vexing philosophers ever since the discipline got started in ancient Greece. As early as 500 years BC, Heraclitus was musing about the ever-changing nature of a flowing river, recorded by his contemporary Plato with the enduring line, “You cannot step in the same river twice.”

This issue comes up everywhere. In an astronomy course I took at university, the professor gave us a mind-boggling assignment: calculate the number of atoms in your body that were once part of a living dinosaur. The answer was a lot, and though I don’t recall the exact number, the question could have just as easily been about sharing atoms with Heraclitus, or Plato, for that matter. The point is that most of the molecules in our bodies are being replaced and recycled, all of the time1. Like a flowing river, you are literally not the same bag of stuff that you were last year, or even last week; although a more accurate way to put it might be that you are a bag of somewhat different stuff than you contained before.

This raises a tough question. If a different collection of matter can be the same person, how much has to change before you aren’t yourself anymore? The implications are nearer than you might think. Organ transplants, bionic limbs and electronic implants – including devices implanted in the brain – are all within the range of current medicine. How much of a person’s body can we replace and still consider them to be the same person?

I don’t have the answer, and I’m not sure anyone ever will, although some would argue that it is a mistake to assume that there is anything like a constant “you” in the first place. For example, the philosopher Daniel Dennett contends that the idea of a continuous self is really just an illusion produced by the brain2.

Biology has a thing or two to say about the matter. It turns out that part of what makes you you is other species. Specifically, the ones living inside you: the veritable ecosystem of bacteria and other microscopic organisms inside your gut. Evidence is mounting that the microcosm within is an important part of who we are: it provides a unique signature of individuality. It can also determine future health. It might even be part of what defines us as human, since a new study shows that as we evolved from ape ancestors, so did our inner ecosystems3.

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by Roslyn

Backpedalling on backwards evolution

In a recent post I wrote about irreversible colour changes in morning glory flowers, and how this was promoted as evidence that evolution does not work in reverse1. This is called Dollo’s Law, after the 19th century Belgian paleontologist Louis Dollo. He spent most of his life digging up and reconstructing Iguanodons, but his name lives on in our concept of evolutionary trees. In linguistics, for example, the “stochastic Dollo” model refers to the scenario where words can only arise once in a family of languages2.

Louis Dollo supervising the reconstruction of an Iguanodon

Louis Dollo supervising the reconstruction of an Iguanodon. From Wikimedia Commons.

And the reason Dollo’s name is forever tied to the idea of history not repeating? He wrote that “an organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors.”3

Frogs might prove Dollo wrong. A new study by John Wiens, a herpetologist at Stony Brook University, proves that a South American frog re-evolved the long lost bottom teeth of its ancestors, after going more than 200 million years without them4.

Guenther’s marsupial frog lives in the tropical forests of Colombia and Ecuador. It is the only frog we know of among thousands of species with true teeth in its lower jaw. Nearly all frogs have teeth, but only on the upper mandible. They use their single set for grasping prey items that they swallow whole, rather than chewing. The closest amphibian relatives to frogs, salamanders and worm-like caecilians, have maintained upper and lower teeth. This means that somewhere along the line, early frogs lost their bottom set.

As the odd one out, Guenther’s marsupial frog was originally placed in its own family within the taxonomic order Anura. But early studies of tadpole development and immunological proteins suggested that something was off5. In some ways, the marsupial frog was similar to typical tree frogs in the family Hylidae.

John Wiens’ latest results provide a more comprehensive picture of the early amphibian family tree than ever before. He compiled genetic data from 170 species of frogs, salamanders and caecilians. The new phylogeny firmly places Guenther’s marsupial frog in the family Hemiphractidae, and, by calibrating the new tree with evidence from the fossil record, Wiens can pin down the timing of events in amphibian history. His results show that frogs evolved from a salamander-like ancestor and lost their bottom teeth over 230 million years ago – and Guenther’s marsupial frog regained them quite recently, within the last 17 million years.

Hoatzin chick

The marsupial frog is just the latest in a long line of putative exceptions to Dollo’s Law. Others include fossil ammonites that have lost and regained the coiled form of their shells several times3, and modern slipper limpets that regained the coiled shells of their snail-like ancestors6. Some lizards have re-evolved long lost fingers and toes7. The strange bird known as the hoatzin, which has claws on its wings that are used for climbing until its wings are fully developed for flight, might have re-evolved this feature from its dinosaur ancestry. These examples have led some authors to argue that Dollo’s Law has outlived its usefulness8. Should it go the way of chewing teeth in hens and (most) frogs?

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by Roslyn

Honed

We brought home a new kitchen knife from my parents last month. The knife block was full, but Charlie exchanged the new one for what was previously our smallest and dullest. He wasted no time wrapping the old one up in plastic and hiding it from me. My hand naturally gravitates towards whichever tool will fit nicely inside it, even when I’m cutting a monster squash. We have a good arrangement: Charlie keeps the knives sharp, I keep my fingers, and I toss him the odd carrot slice in return.

But could he eventually be replaced by a sea urchin? A new study in the journal Advanced Functional Materials explains how sea urchin teeth never dull or break. In fact, they get sharper with use1.

Most people are probably familiar with sea urchins as the spiny little balls one occasionally encounters on the beach. Evil looking, but mostly harmless, so long as you avoid stepping on them. Sea urchins live in shallow tidal pools, eating algae and other plant material. So why do they need such sharp teeth? Much like their spines, the teeth probably serve a protective function. The urchins use them to chew burrows, often in solid rock, where they can take shelter from predators and waves.

In the current study, a group of physicists and biologists used an arsenal of sophisticated imaging, chemical and nano-scale stress test procedures to investigate the teeth of the California purple sea urchin (Strongylocentrotus purpuratus). Like starfish and sea cucumbers, urchins are members of a group of animals known for their penta-radial, or five-fold, symmetry. They have five teeth arranged in what is known as Aristotle’s lantern.

Aristotle's lantern

Aristotle’s lantern, as viewed from below with teeth closed. From Killian et al. 20111.

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