Biocomplexity arises when the collective behavior of a biological system overwhelms the behavior of the individual components of the system. For example, microorganisms strongly influence and are influenced by the biogeochemical processes in their environment. They communicate by quorum sensing, as well as through exchange of genetic components. The result is a cooperative state of biological matter that can only be properly described by treating all components together, ranging from the genome, through the cellular and community structure, to the ecosystem level. Moreover, the multiscale structure of biological systems can only be fully understood from understanding their evolution. The Biocomplexity Theme (BCXT) strives to develop a quantitative perspective that is capable of addressing system-scale phenomena using techniques and concepts from statistical physics, mathematics and computation, as well as diverse expertise in evolutionary ecology, in particular, microbial ecology. Systems of interest to BCXT include: geothermal hot springs and other extreme terrestrial environments that are habitats for microbes; complex communities of bacteria that inhabit the gastrointestinal tract of animals, including humans; and the biosphere of the early Earth. As a result of this breadth, BCXT is highly interdisciplinary, including chemists, microbiologists, geologists, physicists, and engineers.
BCXT currently has as its main focus an ambitious project to explore the nature of life on Earth during its first billion years, before the time that life had evolved modern cells, or even species and Domains as we know them today. This project involves a multi-faceted exploration of the evolution of the cell’s core machinery, as well as efforts to probe how cells sense and respond to their environments, potentially altering their rate of evolution. This work is helping to define the basic principles that underlie life, in a manner that should be applicable to life elsewhere in the universe. The Theme’s work in this area is funded through the NASA Astrobiology Institute network.
Through its focus on the interplay between evolution and ecology, the work of the Theme is directly applicable to several major societal challenges. For example, it is now recognized that bacteria have on a global scale evolved resistance to antibiotic drugs. What are the evolutionary mechanisms that allowed this to occur on a time scale of decades, rather than millions of years? And can one devise treatments that are able to mitigate these mechanisms? Remarkably, it appears that the rapid evolution of antibiotic resistance is a vestige of the same processes that led to the rapid evolution of life itself. Thus the Theme’s research into the fundamentals of living systems may have a direct impact on human health, and the Theme is active in developing new approaches to personalized medicine in partnership with researchers at the Mayo Clinic. Other ecological issues addressed in BCXT could have an impact in areas such as bioremediation of toxic waste, energy production, and soil improvement and stabilization.