The natural world is infinitely complex and hierarchically structured, with smaller units forming the components of progressively larger systems: molecules make up cells, cells comprise tissues and organs that are, in turn, parts of individual organisms, which are united into populations and integrated into yet more encompassing ecosystems. In the face of such awe-inspiring complexity, there is a need for a comprehensive, non-reductionist evolutionary theory. Having emerged at the crossroads of paleobiology, genetics, and developmental biology, the hierarchical approach to evolution provides a unifying perspective on the natural world and offers an operational framework for scientists seeking to understand the way complex biological systems work and evolve.

Coedited by one of the founders of hierarchy theory and featuring a diverse and renowned group of contributors, this volume provides an integrated, comprehensive, cutting-edge introduction to the hierarchy theory of evolution. From sweeping historical reviews to philosophical pieces, theoretical essays, and strictly empirical chapters, it reveals hierarchy theory as a vibrant field of scientific enterprise that holds promise for unification across the life sciences and offers new venues of empirical and theoretical research. Stretching from molecules to the biosphere, hierarchy theory aims to provide an all-encompassing understanding of evolution and—with this first collection devoted entirely to the concept—will help make transparent the fundamental patterns that propel living systems.

Palomitáy is an orphanage in highland Peru that provides a home for unmarried mothers as young as twelve years old. In their ordinary lives, these young women encounter diverse social expectations and face moral dilemmas. They endeavor to create a ‘good life’ for themselves and their children in a context complicated by competing demands, economic uncertainties, and structured relations of power. Drawing on a year of qualitative on-site research, Krista E. Van Vleet offers a rich ethnography of Palomitáy's young women. She pays particular attention to the moral entanglements that emerge via people's efforts to provide care amid the inequalities and insecurities of today's Peru. State and nonstate participants involved in the women's intimate lives influence how the women see themselves as mothers, students, and citizens. Both deserving of care and responsible for caring for others, the young women must navigate practices interwoven with a range of a racial, gendered, and class hierarchies. Groundbreaking and original, Hierarchies of Care highlights the moral engagement of young women seeking to understand themselves and their place in society in the presence of circumstances that are both precarious and full of hope.