RSS FeedPenetrating Observations: Grim Reaper Edition
- Researchers using DNA analysis are “85% sure” they’ve identified the remains of Italian painter Caravaggio (1571-1610) in a small church in Tuscany. And it seems that Caravaggio, an artistic genius with homicidal tendencies, probably died from conditions exacerbated by lead poisoning resulting from heavy exposure through his paints. From the levels of lead in his bones, the exposure would have been enough to cause or contribute to his famous behavioral problems. Hat tip: Ed Yong.
- Christopher Hitchens doesn’t drink nearly as much as we all think he does. But he’s still a tragically good example of the conclusion of this recent study: we humans are getting “better” at making decisions that may kill us.
- Caffeine can kill you too…if you consume a whole lot of it at once. Calculate how much of your favorite beverage will kill you here. Via Mind Hacks.
- Even salsa can kill you! Well, no, not really. But salsa-borne bacteria can make you sick, and you could potentially die from that. Anyway the CDC says outbreaks of food-borne illness from salsa and guacamole rose to 3.9% of all food-borne outbreaks in 2008, up from 1.5% in the late nineties. Via Food Politics.
- Aeschylus (524–455 B.C.), Greek tragedian who orchestrated epic dramas of fates, furies, and the meaning of justice, apparently died from a cranial injury when an eagle dropped a turtle on the playwright’s bald head, probably mistaking it for a rock upon which to crack open the turtle’s shell. Via Mind Hacks.
Diagram of the Day
In case you ever need it, here’s a sort of workflow diagram for refurbishing a lung and transplanting it into a rat:
Via Ed Yong, who writes:
In a lab at Yale University, a rat inhales. Every breath this rodent takes is a sign of important medical advances looming on the horizon, for only one of its lungs comes from the pair it was born with. The other was built in a laboratory.
This transplanted lung is the work of Thomas Petersen and a large team of US scientists. Their technique isn’t a way of growing a lung from scratch. Instead it takes an existing lung, strips away all the cells and blood vessels to leave behind a scaffold of connective tissues, and re-grows the missing cells in a vat. It’s the medical equivalent of stripping a house down to a frame of beams and struts and rebuilding the rest from scratch. The whole process only took a few days and when the reconstituted lung was transplanted into a rat, it worked.
Everyone Who Ever Lived
Global population growth is on track to reach 7 billion in 2011. We hit 6 billion just 11 years ago, in 1999.
So, how big is the set of all people who have ever lived on Earth? About 107 billion, if estimates I’ve adjusted from the Population Reference Bureau are correct (I’ve added 600 million to their 2002 numbers and rounded down). That would mean that about 6% of everyone who ever lived is alive today.
This infographic, from Jon Gosier, helps to visualize the numbers:
Click to enlarge.
Via coolinfographics.
Weekend Wordery: Nicaraguan Sign Language
Yuri Mejia, a student at the Escuelita de Bluefields school, signing “friend” in Nicaraguan Sign Language. Credit: Christina Gomez-Mira; courtesy of Nicaraguan Sign Language Projects, Inc.
Until the early 1980s, deaf children in Nicaragua were mostly kept at home and did not attend school. They did not learn any kind of systematic sign language. But after the Sandinistas came to power in 1979, determined efforts were made to improve the country’s education system, which had until then been one of the poorest in Latin America.
Deaf children were put into schools and taught Spanish, lipreading, and fingerspelling signs—with dismal results. However, outside the classroom, the children began to improvise signs to communicate with each other. At first their signs were like pantomime, and each child signed differently from every other child. But when a second wave of very young children enrolled in the deaf schools, something remarkable happened. The younger children signed more fluidly, more expressively, and with more complex and systematic combinations. They had spontaneously standardized their grammar. By the mid-80s, Nicaraguan Sign Language (NSL) was well established.
NSL has afforded psycholinguists the unique opportunity to study a language in its infancy. New research led by Jennie Pyers elaborates the deep implications that language acquisition has for the development of other kinds of cognitive function. The study involved two cohorts of NSL signers: a group of pioneers whose early form of NSL lacked specific conventions for indicating spatial position (e.g., right, left, over, under); and a younger group who had learned the more developed NSL that did include basic spatial vocabulary. Ed Yong describes:
Pyers compared the abilities of people from both groups, now fully grown adults, in two spatial tests. First, she led them into a small room with a single red wall. She hid a token in one corner of the room, blindfolded the [subjects] and spun them around until they lost their bearings. When she removed the blindfold, the [subjects] had to say where the token was. The second test, like the first, involved hiding a token in the corner of a room, but this time the room was a tabletop model that was rotated while the [subjects] were blindfolded.
In both tests, the second group of adults (who learned the more advanced form of NSL) outperformed the first group. Even though their memories and ability to understand the tasks were just as good, the expanded vocabulary of geographical gestures that they learned as children also gave them better spatial abilities well into adulthood.
[...] Pyers explains, “The first-cohort signers find these tasks challenging because they do not have the language to encode the relevant aspects of the environment that would help them solve the spatial problem.”
This is a step beyond evidence that language shapes our experience. It is evidence that the development of certain types of cognitive function is contingent upon language acquisition.
References:
- Pyers’ paper at PNAS: http://dx.doi.org/10.1073/pnas.0914044107 (Note that this link will not reach its target until the post-embargo publication window opens. It might take a few weeks for that to happen.)
- Photo via NSF.
How Did Prehistoric Sea Dragons Keep Warm?
Prehistoric dragons that lived in the sea were able to (a) exist and (b) regulate their internal body temperatures, holding it above 24°C even when swimming in 12°C water, according to research described by Ed Yong. Yong notes that researchers still do not understand how the giant reptiles managed to keep their body heat up.
I dunno. Maybe something to do with breathing fire?
Weekend Birdery: The Rook and the Pitcher
In Aesop’s fable “The Crow and the Pitcher,” a thirsty crow finds a pitcher of water and tries to drink from it, but the water level is too low to reach with its beak. So the crow drops pebbles in the pitcher, one at a time, raising the water level to the top where the crow can drink it.
A study published last August shows that rooks (relatives of crows) are able to reach the same solution as the crow in the fable. In the video below, a rook is presented with a cylinder containing a worm floating on the surface of water that is below reach of the rook’s beak. When provided with some small stones, the rook carefully drops them in the cylinder until the water level rises enough for the rook to reach the worm.
Click to watch video at youtube.
Bird brains, indeed. Via Ed Yong.
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.
Weekend Birdbrainery: Canny Corvid Nutcrackers
A propos of last week’s birdery post, here is video of Carrion Crows in Japan using cars as nutcrackers:
From David Attenborough’s Life of Birds.
Weekend Birdery/Wordery: “Birdbrain”
I don’t think anyone actually uses the pejorative “birdbrain” anymore, but somehow we all know what it means. Maybe from children’s shows or something.
In researching this post, I’ve come to believe that “birdbrain” usage survives now solely as a cheesy trope of news, journal, and (eh hem) blog writing, where it is offered up as an illustration of colloquial folly, a straw man that the author proceeds to dispatch by adducing the latest research in avian intelligence. We at weekend wordery disdain such stale hackery.
On the other hand, we at weekend birdery are not above the occasional prose gimick when necessary. So, whether or not the existence of the term “birdbrain” implicates a widespread belief that birds are stupid, it would be a pernicious myth if it did. And any myth as pernicious as this one should be dispelled at every opportunity, even one fabricated entirely for the purpose of setting it right.
Therefore I am announcing a series of posts, beginning with this one, to illustrate just how smart birds can be. First, a caveat: For the most part, all animals—present conspecifics included—are dumb. But with that proviso, birds are not, relatively speaking, a particularly dumb class of animals. (Note: if you can conjure David Attenborough’s voice in your mind’s ear, cue it up now:) And indeed, as we’ll see over the course of this series, birds are, quite often, remarkably clever. And the cleverest of all the birds…are the corvids.
Corvids, a family that includes crows and jays (as well as rooks, ravens, and magpies), have displayed a measure of cunning that surpasses not only other birds, but also most mammals—even, in some respects, the non-human great apes. Here’s a sampling of what research and observation have taught us about corvid intelligence:
- An individual European Magpie can recognize itself in a mirror (a rare capacity for non-mammals).
- Carrion Crows in Japan have been observed dropping hard nuts in crosswalks, waiting for cars to drive over them and crack their shells. (See for yourself.)
- Ravens have exhibited the ability to tactically deceive one another in order to hoarde food or to raid each others’ stashes.
- Western Scrub Jays have demonstrated episodic memory (that is, memory of specific past events ) and the ability to plan for future contingencies based on past experience and observation. (Via Ed Yong.)
- Rooks have evinced an elementary understanding of Archimedes’ Principle, dropping rocks into a tall cylinder to raise the water level therein, so that they could reach a worm floating on the surface. (Watch it. Via Ed Yong, again.)
- Many corvids are known to use tools—for example, a stick to get a grub out of a small hole. But the New Caledonian Crow can make and modify tools (like hooks) and can even use tools to make or acquire other tools.
I’ll explore some of these studies and others in more detail in posts to follow.
A New Caledonian crow uses a stick tool to extract mealworms from a drilled log in the Oxford laboratory.
In Praise of Naps
I enjoy a good nap. In fact, I basically live life perpetually on the brink of nap. (Until the sun goes down, that is, when I become weirdly awake.) And I’ve always thought napping, or sleeping in general, to be one of the most sensible ways of spending one’s time.
It was something of a revelation to me when I read, many years ago, that from the prospective of evolutionary biology, the important question about sleep is not why we do it, but why we do so little of it. What needs explaining is why we spend so much of our time awake, when we could be sleeping. (The answer, in a nutshell: sex.)
Health economist and nap aficionado Austin Frakt brings the science on napping. A recent paper (digested here) addresses the question of whether napping with your head on your desk is as restorative as lying-down napping. The verdict: no, but it’s better than not napping at all.
To my mind, the observation that any napping is better than no napping counts as a priori true. The fact that empirical research now confirms it can only be greeted with…a yawn.
Weekend Birdery: Great Tits
GrrlScientist couldn’t resist the pun in her recent post, “What Do Great Tits Reveal about the Genetics of Personality?”
The post reviews a study of four wild populations of Great Tits (pictured right) in Europe, examining whether certain gene sequences correlated with exploratory behavior. The study found that the potential correlation…well, there was no correlation really.
Oh well. That’s science. If not increasing the store of our knowledge, at least it offers up opportunities for the endless propagation of adolescent puns and intrigue that is weekend birdery.
Tuesday Birdery: Bilateral Gynandromorphs
This is an interesting post from Grrl Scientist about gender-bending birds, like the chicken pictured here, that are sexually dimorphic individuals—one half male, one half female. Split right down the middle. It’s a freakish but actually fairly common phenomenon.
The gist of the research findings on these bilateral gynandropmorphs is that avian cells have a genetically programmed sexual identity that is not subject to the influence of developmental factors (hormones and the like) the way mammalian cells are during embryonic development. Our cells can switch sex roles based on cues received within the cellular environment. Not so for chickens. So, when human cells have genetic aberrations in their coding for male or female identity during development, the cells can often still “make up for it” and form a relatively normal human male or female. Apparently, no such compromise is available for chickens.
Weekend Birdery: The Strange Sex Life of Muscovy Ducks
We interrupt our usual programming for a quick note about the evolution of duck penises. Specifically, that of the Muscovy duck. A Muscovy drake’s penis is extraordinarily long and shaped like a corkscrew.
Muscovy ducks in flagrante
A brief aside: one will not fail to note that Muscovy ducks are rather ugly, to human eyes, primarily due to the bulbous caruncles they have around their faces. To relieve you of any unwanted mental images, I’ve also included a picture of a Muscovy chick below, which is suitably adorable.
Research by Yale’s Patricia Brennan (written up here by Ed Yong and here by Carl Zimmer) sets out to explain what you are no doubt wondering yourself: why corkscrew penises?
The answer: sex wars. Male and female Muscovies have been caught up in an evolutionary arms race of sex-organ development. Ed Yong:
Many ducks form bonds between males and females that last for a mating season. But rival males often violently force themselves onto females. To gain the edge in these conflicts, drakes have evolved large corkscrew phalluses, lined with ridges and backward-pointing spines, which allow them to deposit their sperm further into the female than their rivals. These extreme penises of ducks are even more unusual because 97% of birds lack any penises whatsoever.
But female ducks have developed countermeasures. Their vaginas are equally long and twisting, lined with dead-end pockets and spirals that curve in the opposite direction. They are organic chastity belts, evolved to limit the effectiveness of the males’ lengthy genitals. Two years ago, Brennan showed that duck species whose males have the longest penises tend to have females with the most elaborate vaginas. Now, she has found further evidence that these complex genitals are the result of a long-lasting war of the sexes.
The new evidence includes some amazing videos of the ducks’ ballistic penises. Definitely good for a “woah, dude!” moment.
Who’s winning the war of duck genitalia? Yong says it’s the females. Because of their convoluted vaginas, forced matings result in offspring only 3% of the time.
Suitably adorable Muscovy duckling
Weekend Birdery: State of the Birds
This is the inaugural edition of a new, occasional feature about birds.
This week, the U.S. Department of the Interior released its 2010 State of the Birds report. Woohoo! The theme of the report is how climate change is affecting populations and habitats of the roughly 800 species of bird in America. The report finds that birds in every category of habitat are threatened by climate change, as the graph below illustrates, but particularly vulnerable are the 67 ocean-going species (like albatrosses and petrels) and others that breed on low-lying islands imperiled by rising sea levels.
Relative Vulnerability of U.S. Bird Species by Habitat
Red = high vulnerability; Yellow = medium vulnerability; Green = low vulnerability
Warming trends are amplifying and adding to existing ecosystem stressors. Coastal and island birds face erosion of habitat and disruption of food supply from the increased frequency and severity of storms caused by increasing sea temperatures. Warming can tip the ecological balance towards birds’ predators, invasive species, or disease. (E.g., mosquito-borne avian malaria and pox spread easily through bird populations on islands like Hawaii, where the native species have little natural resistance. And as average temperatures rise and creep up to higher elevations, mosquitos and malaria creep with them.)
One notable and measurable effect of warming has been a northward shift in the wintering ranges of many if the most widespread species in the northern states.
Although many factors are known to drive range changes, results from the Christmas Bird Count (CBC) show that the warmer winters in recent decades have played an important role in shifting winter bird ranges to the north. CBC data from the mid-1960s through 2006 show that 170 (56%) of the 305 most widespread, regularly occurring species have shifted their ranges to the north, whereas only 71 species (23%) have shifted to the south and 64 species (21%) have not shifted significantly north or south.
State of the State of the Birds Report Report
Overall I think the report is nicely presented, and I think the idea of integrating disparate surveys, studies, and data sources is great. I presume the effort provides a helpful backdrop for setting and funding research agendas and for articulating the basis for conservation efforts.
But I must say I’m a little disappointed in this year’s State of the Birds report. For one thing, it lacks a comprehensive overview of, you know, what’s going on with birds in America. I’d like to see some population estimates, lists of endangered and threatened species1, data trends, and such. And while the layout and pretty pictures (bird porn) are nice, the report has an unforgivable paucity of informative charts. (Sorta just kidding about the unforgivable part. But the charts are paltry. Besides the two above, there are some basically pointless pie charts and not a table in sight.)
Altogether it comes off like a promotional brochure, lacking a certain analytical heft—though I have no doubt that it represents serious scientific work product. (See the report in pdf here.)
So: geek that thing up next year, guys! A statistical appendix, maybe. Or at least post some tables and lists on the website.
- There was a table of endangered species in the 2009 report. [↩]
Funniest Paragraph of the Year
This is definitely the funniest paragraph I’ve read all year, from Emily Laut at ScienceNOW Daily News:
When it came to insect penises, Charles Darwin had it right. The famed naturalist suspected that insect genitalia, which are frequently festooned with bizarre combinations of hooks, spines, and knobs, essentially functioned like peacock tails. That is, they helped males beat out their rivals for females. Now, researchers have confirmed this hypothesis by zapping fly penises with a laser.
Via Bradford Plumer at TNR’s energy & environment blog, the Vine.