Friday, November 26, 2010

The Anthro Reader, Vol. 17

If you are in the United States, you may be recovering from a food-induced stupor. Here are some Thanksgiving-themed posts to help you along the way:

At the North Carolina State University blog, Matt Shipman investigates the science behind tryptophan, informing readers that we've been mistaken in blaming tryptophan for the lethargy that follows:
Many people gorge themselves at the Thanksgiving table. During the resultant digestive process, the body diverts as much as 50 percent of its blood to the small intestine, to maximize absorption of calories and nutrients. That means there is less blood available for physical activity. Furthermore, most traditional Thanksgiving meals are high in fat and protein content, which actually slows down the digestive process. So your body is going to be diverting blood to the small intestine for a longer period of time.
At Wonderland, Emily Anthes informs readers that turkeys may help with cancer research:
It turns out that as humans domesticated turkeys, selecting birds for faster growth and bigger breasts, for instance, we also concentrated a genetic mutation that makes the birds particularly susceptible to carcinogens in the environment. In particular, domestic turkeys have a mutation that makes them extraordinarily vulnerable to aflatoxin, a substance produced by a variety of species of the fungus Aspergillus. The toxin is most often found in nuts and seeds–turkeys and other birds may be regularly exposed to the toxins through their diets.
Want to know what turkeys eat? According to the USGS WERC blog, they include small pebbles in their diet to help digest food:
All birds have a gizzard, says Casazza. Located in the digestive system just after the stomach, this thickly-lined, muscular pouch acts like a crude chewer. Since turkeys don’t have teeth, they swallow small pebbles and other hard objects that are stored in the gizzard. As food enters that organ, muscle action crushes the food against the pebbles and the masticated food can then be passed back to their stomach.


If you've had enough turkey, elsewhere at Coturnix, Bora tells us that blogging is nothing new:
Nothing new under the Sun. Apart from technology (software instead of writing/printing on paper), speed (microseconds instead of days and weeks by stagecoach, railroad or Pony Express, see image on the left) and number of people reached (potentially millions simultaneously instead of one person or small group at a time), blogging is nothing new – this is how people have always communicated.
The twentieth century has been an exception in terms of communication, he says. The blind trust we have placed in media not a norm—critical thinking is a bit of our legacy, and though we need to relearn this skill, we're moving in that direction thanks in part to blogs.

What prompts a mother to take the life of her child? Eric Michael Johnson has a feature at the Scientific American guest blog that addresses this question, and investigates prolonged stress as a potential explanation. Using a study on stress and rhesus macaques, Eric demonstrates how class differences may add to stress and impact maternal behavior:
The team analyzed the colony’s mortality records covering a period of ten years and found that infants born to low-ranking females were much more likely to die in their first year than those born to high-ranking ones. As a result, low-ranking mothers were living in a state of constant panic. They would watch as their offspring were confronted by dangerous group members but they were powerless to do anything about it. Unable to act while their innate warning system screamed at high alert, their anxiety simply grew, expanding out of proportion as a result of the social inequality.
Eric finds that infant mortality is highest in places where class differences are prominent, as in New York, Colorado, and Oklahoma. Could one of the consequences of inequality be increased rates of infant mortality?

When you're finished with Eric's piece, you may also want to read David Dobb's response at Wired:
I would love to see, for instance, those low-ranking, stressed out monkey mothers in the Maestripieri study split by genotype. For as I noted in an article about stressed-out rhesus moms that Suomi studied, neurotic rhesus mothers in low social positions are more likely to raise neurotic, low-status offpsring if the mothers themselves were a) raised in such circumstances themselves and — a huge and — b) they carry the S-allele of the serotonin transporter gene, which is associated with greater sensitivity to environment in general and social experience in particular. It’s this combination that produces the risk — that creates a disproportionate number of the overanxious, undernurturing moms, the high cortisol levels and low social skills, the self-perpetuating loop of low status and inherited and taught dysfunction.
The two pieces together offer an insightful discussion on nature and nurture.

At the Science 3.0 network, GeneGeek delves into ornithophobia, the fear of attacking birds (think Alfred Hitchcock), but GG has problems with he flapping. She tells us about overcoming her fears during a visit to the Galapagos where she had the opportunity to feed Darwin's finches:
So, at this wonderful house, we were all supposed to put birdseed in our hands and let the birds fly all around us. Really?!? I am proud to say that I did it and it was one of the most scary things I’ve ever done. And I’ve kayaked in white water and over waterfalls, gone hang gliding, and other adventure things.
GG asks whether phobias are adaptive or biologically driven. Why not head on over and congratulate her on feeding the finches and join the conversation?

Hope everyone had a wonderful Thanksgiving! See you Monday.

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