Geoscience enrollments up; supply lags demand
Brazilian Megafauna: hard to hunt or to chew?
What’s wrong with Steve Jobs, revisited
Dinosaurs provide clues about the shrunken genomes of birds
Influenza season, part 2

Related to yesterday’s post,The neural bases of empathic accuracy:

Theories of empathy suggest that an accurate understanding of another’s emotions should depend on affective, motor, and/or higher cognitive brain regions, but until recently no experimental method has been available to directly test these possibilities. Here, we present a functional imaging paradigm that allowed us to address this issue. We found that empathically accurate, as compared with inaccurate, judgments depended on (i) structures within the human mirror neuron system thought to be involved in shared sensorimotor representations, and (ii) regions implicated in mental state attribution, the superior temporal sulcus and medial prefrontal cortex. These data demostrate that activity in these 2 sets of brain regions tracks with the accuracy of attributions made about another’s internal emotional state. Taken together, these results provide both an experimental approach and theoretical insights for studying empathy and its dysfunction.

Obesity May Have Offered Edge Over TB:

Over the course of human evolution, people with excess stores of fat have been more likely to survive famines, many scientists believe, living on to pass their genes to the next generation.
But these days, obesity is thought to be harmful, leading to chronic inflammation and metabolic disorders that set the stage for heart disease. So what went awry? When did excess fat stop being a protective mechanism that assured survival and instead become a liability?
A provocative new hypothesis suggests that in some people, fat not only stores energy but also revs up the body’s immune system. This subgroup may have enjoyed a survival advantage in the 1800s, when people were plagued by a disease that decimated Europe: tuberculosis.

The original paper is here. I’m skeptical, but I’d like people who know more about the history and distribution of tuberculosis to weigh in. My working assumption is that excess fat was helpful in most pre-modern contexts (i.e., female fertility) and obesity wasn’t common and simply a modern overshoot.

Obesity May Have Offered Edge Over TB:

Over the course of human evolution, people with excess stores of fat have been more likely to survive famines, many scientists believe, living on to pass their genes to the next generation.

But these days, obesity is thought to be harmful, leading to chronic inflammation and metabolic disorders that set the stage for heart disease. So what went awry? When did excess fat stop being a protective mechanism that assured survival and instead become a liability?

A provocative new hypothesis suggests that in some people, fat not only stores energy but also revs up the body’s immune system. This subgroup may have enjoyed a survival advantage in the 1800s, when people were plagued by a disease that decimated Europe: tuberculosis.

The original paper is here. I’m skeptical, but I’d like people who know more about the history and distribution of tuberculosis to weigh in. My working assumption is that excess fat was helpful in most pre-modern contexts (i.e., female fertility) and obesity wasn’t common and simply a modern overshoot.

Social Competition May Be Reason For Bigger Brain:

“Our findings suggest brain size increases the most in areas with larger populations and this almost certainly increased the intensity of social competition,” said David Geary, Curator’s Professor and Thomas Jefferson Professor of Psychosocial Sciences in the MU College of Arts and Science. “When humans had to compete for necessities and social status, which allowed better access to these necessities, bigger brains provided an advantage.”
The researchers also found some credibility to the climate-change hypothesis, which assumes that global climate change and migrations away from the equator resulted in humans becoming better at coping with climate change. But the importance of coping with climate was much smaller than the importance of coping with other people.

At the link above it says that the paper is in press in Human Nature. Actually I think they must be looking at an old press release, because the description of the paper matches perfectly this paper published in January, Testing Climatic, Ecological, and Social Competition Models:

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The GSS asks people about the morality of premarital sex between post-pubescent minors (TEENSEX):

What if [a male and female] are in their early teens, say 14 to 16 years old? In that case, do you think sex relations before marriage are always wrong, almost always wrong, wrong only sometimes, or not wrong at all?

Most people say “always wrong,” so I’ll just look at those responses; the other responses have little room to vary since all must add up to 100%. How does opposition vary across demographic groups? [1] As for social class, the elites say they’re more ethical than the rabble, but on the other hand, they’re big supporters of “sex is natural and therefore can’t be harmful.” So which is it?

Let’s see what the data say:

Clearly, those with more prestigious jobs (SEI) are less opposed. Perhaps this is because the prestigious can get away with more shocking or outside-the-mainstream views. But that’s not what the three other measures of social class suggest.

As for real income (REALINC, in $5000 intervals), opposition increases from poor to lower-middle income people ($40K), and then declines somewhat steadily among middle and upper income people. My guess here is that middle and upper income people don’t think the teenage years count — as long as their kids get advanced degrees, make a lot of money, and don’t marry scumbags, they could care less if they fool around a little in high school.

Poor people, though, see their kids as living shorter lives — they enter Adult World sooner, so it matters what they do right after puberty. If you live in the same town you grew up in and plan to get married in your early 20s, having a reputation as a slut in high school will harm your prospects a lot more than if you move across the country five times before marrying, and even then only 10 years after graduating.

Education (EDUC) and intelligence (WORDSUM) show a similar pattern to job prestige and real income, as all are indicators of social class. Opposition increases up through 6th grade graduates, but declines pretty steadily among those who made it through middle school and beyond. For intelligence, like the other class variables, there’s an increase among the below-average, and then a steady decline among the above-average.

So, judging by these four ways of measuring social class, there seems to be a real difference between the upper, middle, and lower groups in how fast or slow they expect their children to grow up and do adult things. In biology jargon, this is a difference in life history strategies. There’s a parallel here between parents who invest more in their sons or their daughters, according to the Trivers-Willard Hypothesis: richer families favor their sons, while poorer families favor their daughters. One study found support for this idea by looking at how Gypsy vs. Hungarian families in Hungary invested in their children (free PDF here). Since lower class families care more about their daughters, they’ll freak out more if they engaged in premarital sex while still young and thus when reputations matter most. Upper class families will be thinking of their sons, though, and conclude, “Meh, let them sow their wild oats, as long as they settle down when the time comes.”

[1] It seems like younger people would be least opposed, since 14 to 16 is awfully close to their own age. They might think the police will come after them next. Sure enough, age is a very strong predictor here — indeed, the only demographic group I could find among whom a majority doesn’t consider it “always wrong” is 18 year-olds.

It’s hard out there being a reproductively fit couple

Why are most genetic associations found through candidate gene studies wrong?
What Darwin Said – Part 2: Mechanisms of Evolution.

So claims a researcher whose work will be published in the Journal of Zoology, Dinosaurs shed a few tons in science makeover:

“We have found that the statistical model is seriously flawed and the giant dinosaurs probably were only about half as heavy as is generally believed.”
The research does not suggest that dinosaurs were shorter in length or height. These dimensions are clear from the size of their bones. Instead, Packard’s work challenges the depiction of many giant herbivores. Until now they have been shown as well-rounded, powerful animals, when they are more likely to have been skinny and muscular.

I remember reading stuff in grade school in really old books about how sauropods spent most of their time in water they were so massive. So times change. But nevertheless it seems a bit disappointing that the biggest land creatures in the history of the world weren’t quite as big.

Over the past week the political events in Iran have saturated the news. But the reality is that Pakistan still has an enormous refugee problem, right next door to Iran in fact. It’s striking though that there is little news coverage of this at this moment, at the same time that the public and media’s imagination has been captured by the shocking death of Neda Soltai, the young Iranian woman whose death was caught on video.
Below the fold are the number of tweets on #neda vs. #pakistan (currently the #pakistan hash-tag is concerned with a cricket win by their national team).

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