Annals of Evolution: What Are Goosebumps?
Like hiccups, goosebumps are a QWERTY phenomenon. They are relics of our evolutionary heritage. Rob Dunn explains:
When our ancestors were covered in fur, muscles in their skin called “arrector pili” contracted when they were upset or cold, making their fur stand on end. When an angry or frightened dog barks at you, these are the muscles that raise its bristling hair. The same muscles puff up the feathers of birds and the fur of mammals on cold days to help keep them warm. Although we no longer have fur, we still have fur muscles just beneath our skin. They flex each time we are scared by a bristling dog or chilled by a wind, and in doing so give us goose bumps that make our thin hair stand uselessly on end.
Interestingly, it’s these kind of traits—ones that don’t really make sense or contribute to an organism’s current adaptive fitness—that make the most compelling arguments for the theory of natural selection. More examples in Dunn’s piece at the Smithsonian.
Annals of Evolution: What Are Hiccups?
Hiccups are pretty damn weird, if you think about ‘em. And one of the reasons they are weird is that thinking about them does not help you control them. Anyway, it’s something I’ve always wondered about—making it a perfect topic for my occasional series, Things I’ve Always Wondered About. Over at the Smithsonian, Rob Dunn explains:
The first air-breathing fish and amphibians extracted oxygen using gills when in the water and primitive lungs when on land—and to do so, they had to be able to close the glottis, or entryway to the lungs, when underwater. Importantly, the entryway (or glottis) to the lungs could be closed. When underwater, the animals pushed water past their gills while simultaneously pushing the glottis down. We descendants of these animals were left with vestiges of their history, including the hiccup. In hiccupping, we use ancient muscles to quickly close the glottis while sucking in (albeit air, not water). Hiccups no longer serve a function, but they persist without causing us harm—aside from frustration and occasional embarrassment. One of the reasons it is so difficult to stop hiccupping is that the entire process is controlled by a part of our brain that evolved long before consciousness, and so try as you might, you cannot think hiccups away.
In other words, hiccups are a QWERTY phenomenon, a reminder of the path dependence of evolution. See the full piece for more of evolution’s legacy in our daily lives.
This Week in Confirming Things I Always Assumed Were True
- Darth Vader satisfies the diagnostic criteria for Borderline Personality Disorder.
- Multitasking degrades task performance and decreases performance efficiency. (Hat tip to Kevin Drum)
- Statistical study confirms that life on earth has one common ancestor.
- Binge drinking kills brain cells. Specifically, hippocampal stem cells responsible for churning out new neurons, thus potentially causing lasting impairment of brain function. At least, that’s true for adolescent monkeys. A reasonable bet says it’s true for adolescent humans, too. Via Ed Yong.
Things I’ve Always Wondered About: Cooling-Saucer Edition
According to legend, George Washington explained the existence of the Senate with the metaphor of pouring coffee into a saucer to cool it. Popular passions holding sway in the House would be poured into the senatorial saucer to cool so that legislation would be tempered with the caution and wisdom of the country’s elite.
Okay, so I get the tenor of the metaphor, but the vehicle baffles me. How is this supposed to work exactly? You pour the coffee or tea out of your cup onto the saucer. Hmmm…already foreseeing problems. Ever tried to pour just a little bit of liquid from a full cup without a spout? Well, anyway, imagine you pull that off. Then what? You’ve got a saucer full of drink. Now where do you put the cup? Okay, say you have two saucers. You put the cup down on saucer no. 2, the dry one.
Time for a drink! But, well, er…the beverage—now admittedly cooler—is in a shallow pool on saucer no. 1. Seems like it might be difficult to pick up the saucer and bring it slowly to your lips for a sip without spillage. And surely President Washington will be horrified if you lean over and stick your face in the saucer. This is highly awkward. Moreover, Rule #96 of Washington’s forbidding Rules of Civility & Decent Behaviour in Company and Conversation: a Book of Etiquette is clearly analogous here:
96th It’s unbecoming to Stoop much to ones Meat[.] Keep your Fingers clean & when foul wipe them on a Corner of your Table Napkin.
But say the father of our country is understanding of this predicament, and the bend-over maneuver is sanctioned by the ROCDB in these narrow circumstances. What’s the plan now? Slurp? Oh no. Definitely not. Rule #99:
99th Drink not too leisurely nor yet too hastily. Before and after Drinking wipe your Lips breath not then or Ever with too Great a Noise, for its uncivil [sic].
Lap it up with your tongue? Not while Rule #16 is in effect:
16th Do not Puff up the Cheeks, Loll not out the tongue rub the Hands, or beard, thrust out the lips, or bite them or keep the Lips too open or too Close. [sic]
Loll not out the tongue, you see. We’re swiftly running out of options here, Mr. President. Well, it turns out, according to the Memorial Hall Museum Online, there was a technological solution: deep saucers.
In the 1770′s and 1780′s it became fashionable to drink tea from the saucer, perhaps to allow the tea to cool. One consistent characteristic of tea wares at that time was the deep saucer, borrowed from China. Later in the century, cup plates became part of the tea set and allowed the tea drinker to “park” her cup on the small cup plate while she sipped tea from the saucer….
And there you have it. Deep saucer illustrated below. I’m still not sure how you’re going to negotiate the pouring from the cup to the saucer…unless you bypass the cup altogether and pour directly from the pot into the saucer. In which case: why the cup? But there are limits to one’s curiosity.
Cup and saucer, circa 1725
Things I’ve Always Wondered About: Global Warming Edition
If the hole in the ozone layer lets in harmful rays from outer space, doesn’t it also let them out? And if the hole is repaired, won’t that trap even more heat in the atmosphere? Yes, it seems. Bradford Plumer:
The bad news, alas, is that a big reason Antarctic summers are still relatively chilly appears to be the hole in the ozone layer, which strengthens circumpolar winds and shields the continent from global warming. But since we’ve banned CFCs (with good reason), the ozone layer’s slowly on the mend, and as it heals, the greenhouse effect will take over and Antarctic summers will heat up even more in the coming decades, according to Marco Tedesco, an atmospheric scientist at the City College of New York. It’s like we just can’t win.
Of course, that doesn’t mean we should just sit back, crack open a can of CFCs, and let the planet bake. It sounds like the Senate Majority Leader agrees and is planning to charge ahead with a climate bill this spring.
From September 21-30, 2006 the average area of the ozone hole was the largest ever observed, at 10.6 million square miles. This image, from Sept. 24, the Antarctic ozone hole was equal to the record single-day largest area of 11.4 million square miles, reached on Sept. 9, 2000. ... The blue and purple colors are where there is the least ozone, and the greens, yellows, and reds are where there is more ozone. Click image to enlarge.
Credit: NASA.
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