Deep in the forests of Madagascar, one woman is rewriting the fate of a lemur species once thought to be lost. The greater bamboo lemur was on the brink of extinction — until Maholy Ravaloharimanitra.

Evolution is driven by a process called natural selection. And there's no better place to see how it works 'than in the forests of Madagascar. There, at the top of the tree, is an Indri, which is ...