The curious case of the vanishing penis. "One of the most puzzling events in evolution is the reduction and loss of the phallus in birds." Puzzling indeed. Although birds' ancestors started out with a penis, it was lost by all but about three percent of the bird species currently alive on the planet. Although we're still arguing over why, we now know how the penis goes missing. And it comes, in part, by methodology that I never thought I'd see in a scientific paper: an examination of the genitalia of emus, which do have penises (as do ducks).
Chickens, however, do not. And the difference all comes down to one protein. All birds seem to form a bit of tissue that has the potential to generate a penis, but chickens activate a gene called BMP-4, which kills off the tissue; emus and ducks don't activate that gene. Somewhat intriguingly, BMP signaling is also responsible for killing off the tissue that would otherwise leave us with webbing between our digits.
There are scientists in foxholes. When people are under stress, they tend to rely on whatever it is they believe in. Until recently, that typically meant traditional religion. But with a general decline in belief, what have people turned to? Possibly science, if a new study is to be believed. Researchers created a series of questions that measured people's belief that science makes sense of the world and can improve the human condition. They then administered it to a bunch of rowers, some before an important competition (not exactly a military battle but those haven't happened near Oxford in a while) and others before a practice session. Those facing an important competition tended to place a much higher value on science than their peers who were just in for practice.
I know you're watching me, so I'll act quickly. It's easy to watch an animal going about its business and forget that it's making constant decisions: is that food? Does that motion pose a threat? We can't get inside an animal's brain to see what feeds into the those decisions, but we can test individual factors. And it turns out that one of those factors is a human gaze. In a variety of species, animals respond differently if a human is staring at them than if the person's attention is elsewhere (presumably, the same applies to other animals that could pose a threat). The new work shows that this effect may in part come down to accelerated decision making.
If a researcher stared at magpies while approaching them and they flew away, that whole senario happened much more quickly than if the person's gaze were averted. But the magpies also went back to eating more quickly if the human was staring at them. So the quick response to threats isn't just a matter of a panicked retreat in the face of a threat.
Please send calories with your sperm. In the human dating scene, dinner usually occurs before any attempts at sex. Squid end up providing a meal during sex. Scientists fed male squid with some radioactive carbon, and found that, after sex, females incorporated that carbon into a variety of tissues, using it both for their own benefit and to produce more eggs. Since these squid can store sperm for up to three weeks, there's a good chance that any extra eggs produced thanks to this meal will be fertilized with the sperm that was transferred with the meal.
Odds are, there is a doctor in the house aircraft. Or at least a nurse. Ever worry that the worst possible place to have a medical emergency is stuck on a flight somewhere over the Atlantic? Relax—it's relatively rare, and chances are you'll be well cared for. The rate of medical emergencies is only one in every 604 flights and, on 48 percent of these, there was a doctor on the plane to assist with the care; nurses or EMTs were present on another 28 percent. Only about seven percent of the incidents were severe enough to warrant diverting the flight, and only 0.3 percent of those receiving care ended up dying.