, November 10 The week's most sensational news came from a PNASstudy which heralded the repair of damaged rabbit penises by rebuilding crucial erectile tissue. The researchers proved that they could engineer new corpora cavernosas, the column of tissue that engorges with blood during male arousal, and the male rabbits demonstrated that their new parts worked just fine by mating and fathering offspring. While the technique isn't ready for humans yet, researchers have high hopes that they'll soon be able to help men who need penile reconstructive surgery. Spammers presumably have high hopes that they'll soon be able to fill your inbox with messages touting the rabbit penis cure. Human Reproduction, November 10 Since we have two stories that related to male sexual health, we'll get them both out of the way. Then we'll move on, we swear. This second study raised yet more troubling questions about the plastic chemical bisphenol A (BPA) that is found in everything from baby bottles to canned food linings. The researchers tracked the sexual health of more than 600 Chinese factory workers exposed to high levels of BPA, and found the men were four times more likely to suffer from erectile dysfunction and seven times as likely to have difficulty with ejaculation than factory workers who weren't exposed to the chemical. Previous animal research has linked BPA to a host of other health problems, including fertility problems, cancer, and diabetes; this U.S. government-funded study seems to strengthen the case for taking the chemical off the market.
Proceedings of the National Academy of Sciences
, November 12 The source of human language has tantalized scientists since our species began asking why we're different from our primate cousins. At the genetic level, researchers are starting to home in on the mechanisms that give rise to speech. The key gene FOXP2 was first identified in the 1990s when researchers found a family with inherited language problems and a mutation that interfered with the gene. Now, a new study has determined that the human version of the FOXP2 gene differs in just 2 of its 740 amino acids from the chimpanzee version of the gene. Could those two changes have given us the gift of speech? Researchers say it's possible that the changes could have had a large impact, because the FOXP2 gene acts like an orchestra conductor, and the human version controls the activity of at least 116 other genes. Another study in Nature shifts the focus from the mysteries within to the conundrums of the cosmos, astronomers staring out at the stars realized that those stars with planets contain far less of the element lithium than planet-less stars. All the lithium in the universe is thought to be leftover from the Big Bang, and in the core of stars its gradually destroyed--but it can linger on stars' surfaces. It's possible, astronomers say, that a star with planets loses its lithium because the planets' gravitational tugging on the star helps mix up its interior.
, November 13 In yet another confirmation that global warming's impacts are already upon us, a new study examined the melting of the Greenland ice sheet and found that since 2000 there's been an accleration in the rate of melting. The ice loss is a combination of icebergs breaking away and meltwater runoff from the surface. The fate of the Greenland ice sheet is of enormous interest to humanity, because if the entire sheet melted it would raise ocean levels by 20 feet. Nothing so extraordinary is expected in the short term, but Greenland's steadily trickling meltwater is a reminder that we have a limited amount of time to tackle this problem before our planet reaches a tipping point.