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2007-07-03, 17:24:18 If you're terrified of birds, this post might give you nightmares.
The biggest bird that ever prowled the skies, a gigantic condor-like creature known as Argentavis, had a sprawling wingspan of more than 6 meters (21 feet). But a new study of the bird's aerodynamics suggest it was so big it was barely able to fly. National Geographic News reports : Despite its massive flight muscles and 21-foot (6.4-meter) wingspan, the giant bird probably could not generate enough lift to take off from a level surface, according to a new study. Like human hang gliders, Argentavis probably had to run downhill into a headwind to become airborne, said Sankar Chatterjee of Texas Tech University in Lubbock. "Takeoff capability is the limiting factor for the size of flying birds, and Argentavis almost reached the upper limit," Chatterjee said. "Heavier birds such as the ostrich had to give up flight." Once aloft, however, Arentavis was no ostrich. Despite weighing as much as 16 bald eagles, Chatterjee said, "it was an excellent glider, like a sail plane."
I imagine it had to eat a lot of prey to keep itself alive, and flapping around. So what would it eat? Chatterjee and co-author Kenneth Campbell, of the Natural History Museum of Los Angeles County, say fossil details indicate the species was an active predator. "[The birds' skull] was adapted for catching prey and swallowing it whole," Campbell said. "Its jaw mechanics were not suited for tearing flesh from carcasses, as in vultures, nor for tearing prey animals apart for swallowing, as in eagles and owls." (Read related story: "Terror Birds: Predators With a Kung Fu Kick?" [August 1, 2005].)
But another researcher thinks this bird couldn't fly enough to swoop down and grab its prey, so it must have scavenged from carcasses. Maybe it's not as scary as it seems at first. |
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2007-07-01, 12:32:44 Jack Handey (of Deep Thoughts fame) has a brillant movie in mind: Show monkey in a tree. Narrator says, “The monkey, proud and smart, in his native habitat. But one thing he does not have . . .” Show a giraffe. “. . . is a long neck, like the giraffe. Which is why nature has allowed them to combine forces.” Show monkey on giraffe’s neck. (Note: Monkey may have to be tied on.) Then the narrator says, “The monkey can now see very far, and has protection from predators. And the giraffe has a little friendly guy to ride around on him.” The monkey is shot by a poacher and falls from giraffe. Put ketchup on monkey to make him look bloody, but put something bad-tasting in the ketchup or monkey will lick it all off. Shoot BB gun at giraffe to make him run off. Narrator: “The monkey and the giraffe have been separated.” Show monkey wandering around, injured, lost and alone. Make him trip, using fishing line attached to his leg. (Try to get this on first take, because after that monkey will probably try to bite off fishing line.)...
Read the rest in his piece "My Nature Documentary" on the New Yorker site. |
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2007-06-30, 7:47:13 Paypal Mobile seems like one of the best ideas in a long time—and it's something that people in developing countries pioneered. This service lets you wire money to friends, companies, charities—anyone with a bank account—just by sending a text message. How many times have you been at dinner with people and it's a pain to sort out the change for the bill, or someone shows up with not enough cash and they have to run to the ATM? This Guardian article talks about how a Kenyan company got a program like this started, a little before Paypal did, I think. But as the news article notes (in the correction at the start of the article) the first to do it were two companies in the Philippines. |
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2007-06-28, 16:26:43 I don't usually look at the stats for my site to see how many hits I get, where they're coming from, etc. I used to with my old site a couple years ago, but I got so few hits it was depressing and I stopped doing it. But now it turns out that people actually are looking at my site! I noticed that one of the search terms that was bringing people to my site was "chomsky," so I did a quick Google search for "chomsky natural selection," and found that my blog post from a couple of months ago was the top hit! I hope I got his views correct, since it's a bit subtle what he thinks natural selection and language. Anyway, I'll have to be a little more careful now on my blog posts, now that I know I'm being watched! |
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2007-06-28, 15:30:56 I wrote an article the other day about how researchers might be able to resurrect woolly mammoths and other species that died out in the past 100,000 years or so, by recovering their DNA. The article I was originally going to write was more about a recent paper by Svante Paabo and colleagues, who showed which kinds of errors are common in this ancient DNA, from Neanderthals, cave bears, and mammoths. Scientific American had an article about this, which is basically like the article I originally planned to write. (I saw this first on anthropologist John Hawks' blog.) So if you want more details on what it would take to put together a Neanderthal genome, check out this article. Paabo told me that they're about 1% of the way done with the Neanderthal genome—so I guess that's about 30 million base pairs of DNA, since the human genome (which is almost exactly the same) is 3 billion base pairs. That's pretty impressive, since in October of 2006, they reported analysis of just one million base pairs. Paabo said it's going slower than planned, though. When I asked whether they think it will pick up once they iron out the kinks, he said, "I hope so! Otherwise it's going to take us 99 years to finish it." |
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