The technical way to explain this odd-looking fowl is that it's "gynandromorphous." But if you just want to call it "one seriously confused chicken," that works, too. For a new study in Nature, Michael Clinton and colleagues investigated a few of these half-male, half-female chickens they obtained from chicken farms. Gynandropmorphs show up now and then not just in chickens, but also in parrots, pigeons, and some other kinds of animals. But scientists weren't sure how the mix-up happens, since the standard idea for sex differentiation is that the sex hormones released by the gonads either masculinize or feminize the embryo. Clinton's team
discovered that bird cells don't need to be programmed by hormones. Instead they are inherently male or female, and remain so even if they end up mixed together in the same chicken [BBC News]
. The researchers had first assumed that the half-and-half chickens followed the hormone ...
