Figure 1.

The goals of evolutionary biology are to describe and understand living things, including their distribution, lifestyles, and history. Without microbiomes, we are missing not only the majority of living things on the planet (bacteria) but also important interactions between dynamic forces. Arrows on figure show how different levels of biological organization can affect each other. E.g., eating a butterfly affects (in a broad sense) a bird; the microbiome of the butterfly can also affect the bird, as well as directly affect the microbiome of the bird. Genes and genomes of all living pieces of this “foodweb” interact at many scales and the evolution of all the pieces are connected to many others.