Role of the Gut Microbiome in Vertebrate Evolution.

Darwin referred to life as a struggle. Organisms compete for limited resources in nature, and their traits influence the outcome. Victory carries great weight as winners survive, reproduce, and progenate subsequent generations. Consequently, organismal traits that influence fitness drive adaptation and their discovery clarifies evolution. Recent research implicates the vertebrate gut microbiome as an agent of fitness, selection, and evolution. Going forward, we must define the functional effects of the gut microbiome to determine how it impacts evolution. Specifically, we must quantify how gut microbiome function diversifies in concert with vertebrate radiation and resolve specific functions that influence natural selection. In so doing, we can discover and potentially capitalize upon the mechanisms by which our gut microbiomes impact our physiology and fitness. Ultimately, we may come to find that while life involves struggle, it also depends upon cooperation.