This book is a fascinating and compelling non-technical review of the expanding research of Darwin’s paradigm of Evolution by Natural Selection.  This paradigm elicited vibrant scientific debates, spilling over to social studies and humanities, spanning evolutionary economics, philosophical, religious and historical debates.

This book is an essential read for updating the readers about recent developments and explorations of evolutionary dynamics associated with the role of microorganisms as a key framework for future evolutionary thought. The authors illustrate that classical evolutionary theory requires expansion and revision in light of modern discoveries in molecular genetics, microbiology, and systems biology in the context of the new frontier of evolutionary dynamics.

The authors introduce the reader to the ‘hologenome’ concept, related to their research, illustrating that the unit of selection in evolution is not just the individual organism (host) but the host plus all of its associated microorganisms (the microbiome). The ‘hologenome’ incorporates the genetic information of both the host and its symbiotic microbes. The authors illustrate that this integrated system functions as a cohesive biological entity, with the microbiome playing a crucial role in the holobiont's adaptation, health, and evolution. Changes in the microbiome, which can occur more rapidly than changes in the host genome, and can provide a swift means for the holobiont to adapt to environmental pressures.

The authors effectively illustrate the extended spectrum of research associated with the hologenome concept, including the study of heritable changes in gene expression that do not involve alterations to the underlying DNA sequence - how organisms and their environments mutually influence each other's evolutionary trajectories. The role of learned behaviors and culturally transmitted knowledge in shaping evolutionary paths, particularly in more complex organisms.

This approach suggests that while host genomes evolve slowly, microbiomes can change quickly in response to environmental factors, allowing organisms to adapt more rapidly. Some microorganisms are passed from generation to generation, meaning they contribute to long-term evolutionary changes.  Studies suggest that microbiota can play a role in the formation of new species by influencing traits such as immunity, metabolism, and even home microorganisms that are passed from generation to generation, meaning they contribute to long-term evolutionary changes.  Studies suggest that microbiota can play a role in the formation of new species by influencing traits such as immunity, metabolism, and even behavior.

Notably, the authors also explore the broader implications of evolutionary theories for understanding social phenomena, including biological cooperation versus social Darwinism, Collective memory, and the wide array of issues explored by interpretive research done by Social Science and Humanities.