Microbes and the Origin of Animal Species

Unprecedented attention to our microbial world has in part turned the fields of zoology and botany inward—toward a new awareness and understanding of the universality and complexity of host-microbiota relationships. Here, I present our laboratory's work on the origin of animal species in light of this conceptual shift. Specifically, we ask how do closely related host species vary in their microbial communities? Does host evolutionary history affect microbiota differences between species? And what is the role of the microbiota in reproductive isolation and animal speciation? Overall, answers to these questions indicate that the composition and functional effects of an animal's microbial community can be closely allied with host evolution, even across wide-ranging timescales and in diverse animal systems. Appreciation of microbiology's role in animal speciation will provide a better understanding of Darwin's "mystery of mysteries" in The Origin of Species.