Over the last half billion years, there have been five major mass extinctions, when the diversity of life on Earth suddenly and dramatically contracted. Scientists are currently monitoring the sixth extinction, predicted to be the most devastating since the asteroid impact that wiped out the dinosaurs. This time around the cataclysm is us. In this book the author tells us why and how human beings have altered life on the planet in a way no species has before. She provides a moving account of the disappearances of various species occurring all around us and traces the evolution of extinction as concept, from its first articulation by Georges Cuvier in revolutionary Paris up to Lyell and Darwin, and through the present day. The sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. -- Publisher description.

How might the origins of our species inform the way we think about our planet? At a point of unparalleled crisis, can human ingenuity save us from ourselves? Much-loved writer Ramona Koval travels the globe in a quest for answers, and encounters the unexpected. She talks to an eminent paleo-archaeologist over a two-million-year-old skull in the Republic of Georgia, meets the next generation of robots in Berlin, attends a festival against death in California and explores an ice-age cave in southern France, speaking with the world's leading authority on cave art. Between these and other adventures she returns to her ever-engaging granddaughter Layla, whose development in infancy spurs Koval to find out what makes us human, what separates us from the other apes. Full of revealing exchanges with scientists and writers whose knowledge of the past and visions for the future could hold the key to our next evolution, A Letter to Layla will surprise and delight in equal measure.--