The article "Host Biology in Light of the Microbiome: Ten Principles of Holobionts and Hologenomes" by Seth R. Bordenstein and Kevin R. Theis challenges traditional views in biology by integrating the concepts of holobionts and hologenomes. Holobionts are defined as the host organism plus its associated microbes, and their collective genomes form the hologenome. The authors present ten principles that clarify and expand these concepts, emphasizing their importance in understanding the evolution and biology of animals and plants. These principles include the recognition that holobionts and hologenomes are units of biological organization, that they are not organ systems or superorganisms, and that the hologenome is a comprehensive gene system. They also discuss how the hologenome concept reboots elements of Lamarckian evolution, integrates all mechanisms of mutation, and fits into multilevel selection theory. The authors argue that the hologenome concept does not change the fundamental rules of evolutionary biology but rather provides a more holistic view of biological complexity. They call for a unified approach that integrates the study of both the host genome and the microbiome to advance the field of biology.The article "Host Biology in Light of the Microbiome: Ten Principles of Holobionts and Hologenomes" by Seth R. Bordenstein and Kevin R. Theis challenges traditional views in biology by integrating the concepts of holobionts and hologenomes. Holobionts are defined as the host organism plus its associated microbes, and their collective genomes form the hologenome. The authors present ten principles that clarify and expand these concepts, emphasizing their importance in understanding the evolution and biology of animals and plants. These principles include the recognition that holobionts and hologenomes are units of biological organization, that they are not organ systems or superorganisms, and that the hologenome is a comprehensive gene system. They also discuss how the hologenome concept reboots elements of Lamarckian evolution, integrates all mechanisms of mutation, and fits into multilevel selection theory. The authors argue that the hologenome concept does not change the fundamental rules of evolutionary biology but rather provides a more holistic view of biological complexity. They call for a unified approach that integrates the study of both the host genome and the microbiome to advance the field of biology.