Monday Science Links

This week's science:

• Is economics a science? Well, here's a brilliant piece by Paul Krugman in the NYT Magazine, How Did Economists Get It So Wrong?: It’s hard to believe now, but not long ago economists were congratulating themselves over the success of their field. Those successes — or so they believed — were both theoretical and practical, leading to a golden era for the profession. On the theoretical side, they thought that they had resolved their internal disputes. ... And in the real world, economists believed they had things under control: the “central problem of depression-prevention has been solved,” declared Robert Lucas of the University of Chicago in his 2003 presidential address to the American Economic Association. In 2004, Ben Bernanke, a former Princeton professor who is now the chairman of the Federal Reserve Board, celebrated the Great Moderation in economic performance over the previous two decades, which he attributed in part to improved economic policy making. Last year, everything came apart. Few economists saw our current crisis coming, but this predictive failure was the least of the field’s problems.


• At The Loom, Carl Zimmer talks about disappearing teeth: Charles Darwin was interested not just in how new things evolve, but also in how old things disappear. Often, they don’t disappear completely without a trace. We don’t have a visible tail like our primate ancestors did, but we still have a series of little bones tucked away at the bottom of the spine. While it may not function like a full-blown tail, it still anchors muscles around the pelvis. Blind cavefish may not have eyes of the sort found on their cousins in the outside world, but they still start to develop eyes as larva, before the cells start to die away. Sometimes, though, the only place to look for vestiges of a lost trait is in a genome. In the journal PLOS Genetics, Mark Springer of the University of California and his colleagues have published an intriguing study of how teeth–and the genes for teeth–have faded away over the past 50 million years. In particular, they looked at enamel, the tough covering that caps the teeth of humans and other vertebrates.


• At Why Evolution Is True, Greg has a survey of weird amphibian breeding practices: Feeding unfertilized eggs to tadpoles may seem like a bizarre and exotic way to take care of your offspring (the BBC labeled it an “alien scene”), but it’s actually sort of mundane in the world of amphibians. Amphibians have the most diverse set of modes of reproduction and nutrition of juveniles of all the land vertebrates. Laurie Vitt and Janalee Caldwell, in their superb herpetology textbook, list 40 different reproductive modes for frogs. Its hard to pick a strangest amphibian reproductive mode, but I’d go with either the gastric-brooding frog, Rheobatrachus silus, in which the female swallows her eggs, which develop in her stomach, or histophagy, practiced by several amphibians, in which the fetuses feed upon the mother’s hypertrophied oviductal lining (i.e. while still inside of her).


• Over at Starts With A Bang, Ethan asks how many times would you have to fold a piece of paper to get to the moon (of course, check out the comments for several reasons this is a thought experiment): Well, let's see how we'd figure it out. I don't know how thick one piece of paper is, but I know it's pretty thin. I can, however, estimate how big those 500 page reams are. They're about 2 inches high, so maybe that's about 5 cm. That means one page is about 0.01 cm high. And what of the Moon? Mean distance from the Earth is about 384,000 km, or about 3.84 x 10^12 pages away. So you'd expect that you'll need an awful lot of foldings to get there, right? Well, hang on for a second.


• And over at archy, John has a tale of zombie mammoths, or at least tales: The problem with the internet, we are told, is that it has no standards and no controls. Anything that is written will be recycled endlessly, regardless of whether it is true or not. There is no way to correct bad information on the internet. This is why the internet is inferior to traditional media. At least that's what we're told. In the three hundred years since Europeans first received reports of a mysterious creature in Siberia called the mammoth, nothing has engendered more public fascination about them than the occasional discovery of nearly intact, frozen mammoth carcasses with flesh still attached. At some point in the nineteenth century, frozen mammoths became a staple of catastrophist theories. As one of the usual suspects, frozen mammoths have regularly been trotted out to prove that Atlantis was real, the Earth's axis can suddenly change location, a planet-sized comet caused the plagues of Egypt, or that Noah's global flood was real. Sometimes they prove all of the above. Three particular mammoths show up more often that all of the others combined.

Enjoy!