A biological and cultural biography of the ubiquitous yet mystical seashell.Seashells, stretching from the deep past into the present day, are touchstones leading into fascinating realms of the natural world and cutting-edge science. In Spirals in Time: The Secret Life and Curious Afterlife of Seashells, marine biologist Helen Scales shows how seashells have been sculpted by the fundamental rules of mathematics and evolution; how they gave us color, gems, food, and new medicines. The science and natural history of shells are woven into a compelling narrative, revealing their cultural importance and the ways they have been used by humans over the millennia, even as a source of mind-bending drugs. After surviving multiple mass extinctions millions of years ago, mollusks and their shells still face an onslaught of anthropocentric challenges, including climate change and corrosive oceans. But rather than dwelling on all that is lost, Scales emphasizes that seashells offer an accessible way to reconnect people with nature, helping to bridge the gap between ourselves and the living world. Spirals in Time shows why nature matters, and reveals the hidden wonders that you can hold in the palm of your hand.