Discovered: Male fish who engage in same-sex flirting lure in female fish; cheese dates back 7.5 millennia; Americans love public transportation once they give it a chance; depressed mice cheer up after brain stimulation.
Gay fish attract more female mates. Nature has its own version of a pop culture archetype—the highly attractive man who, unfortunately, remains unavailable to the women swooning over him. A team of researchers led by University of Frankfurt's David Bierbach has found a species of tropical fish in which males who flirt with other males are perceived as more attractive by potential female mates. They observed Poecilia mexicana, or Atlantic mollies, engaged in "mate copying," meaning that females will try to mate with a male fish they've seen interacting sexually with members of their own sex. "Males can increase their attractiveness towards females by homosexual interactions, which in turn increase the likelihood of a male's future heterosexual interactions," says Bierbach. "We do not know how widespread female mate choice copying is, but up to now it is reported in many species, including fruit flies, fishes, birds and mammals [including] humans." [BBC News]
Cheese is really old ... ahem ... well aged. Ancient pottery recovered on a dig in Poland reveals that cheese making could date back as far as 5,500 B.C. University of Bristol researchers led by Richard Evershed discovered fatty milk residue on the shards of sieves. That ruled out previous theories that they were used to make honey or beer. "It's almost inconceivable that the milk fat residues in the sieves were from anything else but cheese," comments University of Vermont nutrition professor Paul Kindstedt. We're glad Neolithic people discovered cheese, because their cuisine sounds really boring without it, consisting mostly of porridge. "They probably would not be the first choice for a lot of people today," Kindstedt says of the cheeses these sieves could have produced. "But I would still love to try it." [AP]
If you can convince Americans to take public transportation, they'll love it. It's hard to convince drivers to try public transportation, so Maya Abou-Zeid of the American University of Beirut and Moshe Ben-Akiva of M.I.T. cut a deal with their experimental subjects: they covered their fare for a brief trial period. They found that 30 percent of Boston car commuters were convinced to switch to public transportation, and 25 percent actually stuck with it for six months. So what was preventing them from switching before? Mostly our societal opinions on public transportation, the researchers found. "Because of a generally weaker public transportation culture in Boston than in Switzerland, M.I.T. participants who switched might not have seriously considered using public transportation until they experimented with it during the trial," they write. [Atlantic Cities]
Brain stimulation cheers up depressed mice. Stanford University neuroscientist Karl Deisseroth has been able to quell depression in mice by stimulating and silencing certain parts of the rodents' brains with lasers. Using optogenetics, the researchers behind two new papers could control nerve cells by adjusting fiber-optic light beams. By better understanding the neural pathways that regulate depression in mice, Deisseroth hopes to develop treatments for humans suffering from depression. "In this way, bit by bit, we can piece together the circuitry," he says. "It’s a long process that’s just starting, but we have a foothold now." [Science News]