Yellowstone National Park Octopus/Mushroom Hot Springs Metagenome

Species are fundamental units in plant and animal communities, but is this true in the microbial world? There is considerable debate as to whether bacteria evolve in fundamentally different ways than eukaryotes due to their rapid reproduction, rare (and promiscuous) sexuality, and evolutionarily significant gene exchange. Modern genetic and genomic analyses make .named. bacterial species (traditionally demarcated by phenotypic properties) appear to be diverse, chaotic assemblages of rapidly exchanged genes. However, modern population genetics analysis challenges the concept that these named species are really biologically meaningful entities. Furthermore, natural patterning of genetic diversity and evolutionary theory suggest a more orderly concept of species as discrete ecologically adapted populations (ecotypes). Our conceptual framework is that ecotypes are the fundamental units of microbial communities that play a central role in linking genetic diversity to microbial community composition, structure and function. We will investigate a well-studied hot spring microbial mat community in Yellowstone National Park with ideal properties for employing sophisticated molecular methods. To understand how genetic diversity is organized in the mat community, we will compare (i) direct genomic sequencing of predominant mat populations (to objectively assay genomic diversity and determine how it is organized according to genetic criteria) with (ii) theory-driven population genetics analysis and evolutionary simulation designed to test for putative ecotypes. Genomic sequencing will enable development of microarray technology and high-throughput analysis of variant alleles that will be used to evaluate whether, as expected, putative ecotypes occupy unique niches and order gene distribution and expression within the mat community. The discovery of genetically separable ecotypes will broadly impact thinking in microbial evolution, systematics, ecology and physiology and will unify evolutionary principles across the breadth of size and complexity among organisms.