Our human family tree used to be a scraggly thing. With relatively few fossils to work from, scientists' best guess was that they could all be assigned to just two lineages, one of which went extinct and the other of which ultimately gave rise to us. Discoveries made over the past few decades have revealed a far more luxuriant tree, however—one abounding with branches and twigs that eventually petered out. In fact, a new species, called Homo naledi (not shown), as yet undated, was announced just last year. This newfound diversity paints a much more interesting picture of our origins but makes sorting our ancestors from the evolutionary dead ends all the more challenging, as paleoanthropologist Bernard Wood explains in this feature from our special issue "The Story of Us."