When actor Alan Alda was 11, he wondered what a flame was. He asked his teacher who told him a flame was “oxidation.” Not exactly helpful, Alda said. “That’s like calling it by another name,” said Alda. “‘A flame, that’s Fred.’” That frustrating moment decades ago resulted in something great—the Flame Challenge, in which scientists compete to accurately and succinctly explain a simple question like “what is a flame?” in a way that an 11-year-old can understand.

Just as inexorably as spring follows winter, so do the complaints about daylight saving time seem to follow moving the clock ahead an hour. Does springing forward really mess up our brains as much as we might gripe about it on Monday morning? We do influence our own bodies with our habits—as anyone who’s had a Saturday night ice-cream-and-feelings bender can tell you—so it’s not totally impossible that we might be able to influence our circadian rhythms with something like shifting our schedule forward or backwards. But can we actually rewind our internal clocks?

“Human kind cannot bear very much reality,” says T.S Eliot. So much reality is forced upon us by the enormity of our manmade global warming that it’s very hard to bear. The world’s leading climate scientists and policy makers are letting themselves say publicly what they’ve long said off-camera: Even the very existence of the human race is threatened. “OPTIMISM FACES GRAVE REALITIES AT CLIMATE SUMMIT” is the all-caps boldface lead headline on the December 1, 2014 New York Times. The second paragraph of the article, setting up the UN’s 20th annual climate summit, held in Lima Peru, reports that uncontrolled global warming could make the world “uninhabitable for humans.”

When we talk about studying, controlling, or just plain worrying about pandemics, we usually think of our own, human diseases. But many other species face existential threats as well. In the wild and on the farm, through climate change, human agency, and other causes, deadly diseases and conditions are ravaging specific animal communities. Here are eight of the scariest diseases plaguing the animal kingdom today.

Our ancestors pass along their beliefs, their stories, and their DNA—and we are only just beginning to understand the impact of genes passed down through generations. In her rich new book, The Invisible History of the Human Race: How DNA and History Shape Our Identities and Our Futures, Christine Kenneally explores the history of genealogy and ancestry, and what we’ve learned about ourselves through advancements in genetics. We had a chance to speak to Kenneally recently about the many legacies of our ancestors.