Senescence

Senescence is Howard Thomas’s personal account of the central role played by selective death in growth, differentiation, adaptation, survival, reproduction and evolution. In the author’s words ‘I wanted to write this book because, after two thirds of a lifetime thinking about senescence, my bonnet is full of bees, my belfry is infested with bats, my cupboard is crammed with skeletons and it’s time they were purged’. Thomas is a plant scientist, and the senescence of plants and their parts is the foundation of the book; but he argues that looking outward from the green world can reveal a fresh perspective on the great expanse of biological ageing.

In seventeen concise chapters, the book ranges from the history and meaning of ‘senescence’ through the birth and ageing of the universe, biological growth and differentiation over time and space, from cell to global scale, responses to beneficial and destructive environmental stresses, the evolutionary origins of senescence, the relationship between death and sex, ripening and food supply, and the boundary between biology and death. A narrative thread runs through the whole book, but each page of text is conceived of as a stand-alone mini-essay which can be read in isolation, fully supported by notes and cited published sources. The writing style is informal and anecdotal, combining accounts of the latest science with references to literature, music and popular culture. The comprehensive index includes a glossary of technical terms, and the book is illustrated in colour throughout.

A particularly provocative bat in the author’s belfry is concern that ideas about biological senescence have become dominated by the biomedical focus on gerontology and the belief that ageing is a curable disease. He reminds the reader that ‘most biology is not human biology. The scientific landscape may be dominated by the dense forest of human ageing and healthcare, but there is a much wider and richer natural panorama in the world beyond’. Senescence will serve as an invaluable guidebook for those who wish to explore this fascinating terrain.