Discovered: Bull sharks can have two heads; women don't want to run for political office; Africa used to have penguins; gangs don't use the Internet.

Bull sharks can have two heads. Brace yourself. Bull sharks — which are known to attack human beings — sometimes come in two. Scientists at Michigan State University came across a bull shark pup with two heads in the Gulf of Mexico after it was cut out of an adult shark's uterus by a fisherman. An MRI of the specimen "revealed two distinct heads, hearts and stomachs with the remainder of the body joining together in back half of the animal to form a single tail." The scientists were quick to address speculation that such a mutation arose from the enormous oil spill which devastated parts of the Gulf in April 2010. "Given the timing of the shark's discovery with the Deepwater Horizon oil spill, I could see how some people may want to jump to conclusions," said one of the scientists. "Making that leap is unwarranted. We simply have no evidence to support that cause or any other." [Journal of Fish Biology]

Women don't want to run for political office. Facebook COO Sheryl Sandberg ignited a storm of debate over the underrepresentation of women in corporate leadership with her memoir, Lean In. But what about women who want to enter political office? According to research performed at American University, "young women are less likely than young men ever to have considered running for office, to express interest in a candidacy at some point in the future, or to consider elective office a desirable profession." The reasons for which, the researchers suggest, are legion — early socialization, the influence of sports, and other cultural factors — and may have as much to do with men wanting to run as women not wanting to run. "Given this persistent gender gap in political ambition," they write, "we are a long way from a political reality in which young women and men are equally likely to aspire to seek and hold elective office in the future." [American University]

Africa used to have way more penguins. Africa, with its diverse (though generally hot) range of climates, isn't known for its black-footed penguins, who live and breed on the southern tip of the African continent. But according to a new study of African fossils, the continent used to host three more kinds of penguins before they mysteriously vanished between 5 and 10 million years ago. "Newly found fossils confirm that as many as four penguin species coexisted on the continent in the past," the study found. "Exactly why African penguin diversity plummeted to the one species that lives there today is still a mystery, but changing sea levels may be to blame." The researchers think that, as sea levels rose, the water destroyed the nesting grounds of the three lost penguin species. [Zoological Journal of the Linnean Society]

Gangs don't use the Internet to commit crime. Gang members are just like everyone else: they use Facebook, tweet, post Instagrammed photos of rainy windows. That, and they tend to keep their gang activities off the Internet, according to two professors of criminal justice who studied the web habits of known gang members. "Much of the online activities of gang members are typical of their age group; they spend time on the Internet, use social networking sites like Facebook and watch YouTube videos." But they're not engaging in, say, identity theft. "Neither gang members nor their peers have the technological competency to engage in complex forms of cybercrime. In short, while the Internet has reached inner city populations, access alone is not translating into sophisticated technological know-how." [Justice Quarterly]