Britt Keith hustled around the kitchen and out into the yard for fresh clippings like an anxious mother hurriedly packing her kids off to school. She gently stuffed a handful of sumac, sweetgum, and tulip poplar leaves into brown paper lunch sacks labeled “Izzy” and “Slausy,” then tore the bags open a bit because Sifakas aren’t big on problem- solving. Carrots, sweet potatoes, in-the-shell nuts and a few other special treats were poured into Ziplock bags.

This might be hard to hear, but you are not an individual. Really, you’re more like a very fecund, populous ecosystem—your moist, oxygenated, constant- temperature body is providing climate-controlled habitat for trillions of living creatures from hundreds of different species. These bacteria form a stunningly diverse, interdependent community of organisms, not unlike a rainforest of biodiversity.

Songbirds, parrots, and humans are rare in the animal kingdom for their ability to hear communication and then repeat it with accurate syntax and pronunciation. Whales and elephants can do this trick, too, but they’re not very practical laboratory animals. Knowing what genetic tools are involved in the bird brain’s speech systems will help Erich Jarvis greatly to tease out each step of the process in humans.

The new family tree of birds rests on whole-genome analysis. Phylogeny for birds and other organisms always has been based on painstaking evaluation of the few available fossils, buttressed since the 1970s by molecular comparisons of selected proteins or a handful of shared genes. But this new tree is based on scanning every last letter of DNA, 1.2 billion letters of genes and non-genes, in forty-eight bird species representing every major order.

The tsunamis have subsided and the continent-sized forest fires have burned out. Gone are the giant dinosaurs and three-quarters of all the other plant and animal species on Earth. They’ve been done in by the cold and dark of 750,000 years of heightened volcanism and the coup de grâce delivered by a six-mile-wide asteroid slamming into what is now Mexico.

Cloud-draped Marojejy National Park rises like a deep green island on a pastel sea of human disturbance. In each muddy quadrangle of rice paddy around the island’s feet, a single cow is staked out to graze and defecate. This rainforest preserve is a dwindling refuge of Madagascar’s native biodiversity, 80 percent of which exists nowhere else on Earth.

 The first genomes to be sequenced revealed something surprising: On a genetic level, we’re not that different from other species—even some very distantly related ones. What makes us human and them not?

Chicita Forman Culberson Ph.D. ’59 has devoted her career to the painstaking task of cataloguing the chemical diversity of lichens, those drab growths one sees clinging to life on rocks and tree trunks in the most unlikely places.

It's hopeless. Try as he might, the eager young suitor with the brick-red eyes simply cannot inspire the beautiful female's affections.