Promiscuity's for the birds

By Agnieszka Biskup, 10/21/2003

Finally, what adulterous female songbirds have always wanted: Scientific proof of the evolutionary advantages of promiscuity. A team of researchers from the Max Planck Research Center for Ornithology in Germany and the Zoological Museum in Norway spent four years studying a population of songbirds known as blue tits breeding in the Viennese Forest in Austria. A female blue tit normally chooses a single social partner, a male to defend a territory and to help care for offspring, but she also occasionally mates with other males outside her breeding territory without her partner's knowledge. The researchers report in the Oct. 16 Nature that they have found that the offspring from these extramarital affairs were more genetically varied than those sired by her social mate, and were more likely to survive and reproduce. Females from these extramarital couplings were found to produce larger clutches of eggs and lived longer. Males from these couplings also produced more surviving offspring. As an added bonus, these males also tended to have more elaborate head crests, assumed to make them more attractive to other females. The study supports the idea that females mate many times to get the best possible genes for their young and gives evidence that evolutionarily speaking -- at least for female blue tits -- promiscuity may be the way to go.

Jettison the fuel!

When you're flying in a jumbo jet, do you ever think about how much of the plane's holding capacity is devoted to carrying fuel? A team of researchers from NASA's Marshall Space Flight Center in Huntsville, Ala., NASA's Dryden Flight Research Center at Edwards, Calif., and the University of Alabama have thought about it quite a bit, and have come up with a way to eliminate aircraft from carrying fuel altogether. They have developed a model airplane that is powered and kept aloft by a laser beam delivered from the ground -- no onboard fuel required. Tracking the aircraft in flight, the beam is directed to specially designed photovoltaic cells onboard, which power the plane's propeller. Robert Burdine, Marshall's laser project manager, said that "the craft could be kept flying as long as the energy source, in this case the laser beam, is uninterrupted." So far, the technology has powered only a small, radio-controlled model airplane that was tested indoors, but hopes are high for its potential use in surveillance and telecommunications. "This is the first time that we know of that a plane has been powered only by the energy of laser light," Burdine said. "It really is a ground-breaking development for aviation."

Hello, Froggy

It may not look much like Kermit, being bloated and bright purple with a long, pointy nose, but a frog recently discovered in the mountains of southern India may well become the next big amphibian celebrity. Described by Franky Bossuyt of the Free University of Brussels in Belgium and S.D. Biju of the Tropical Botanic Garden and Research Institute in India in the Oct. 16 Nature, the frog not only is a new species, but, according to the researchers, warrants the establishment of a whole new frog family of which it is the only member. Named Nasikabatrachus sahyadrensis (Nasikabatrachus is a combination of Sanskrit and Latin meaning "frog with nose"), this "living fossil" diverged from its froggy ancestors during the time of the dinosaurs. In an accompanying commentary, S. Blair Hedges of Pennsylvania State University describes the frog as "a once-in-a-century find."