Everything depends on everything else

In physics the concept of entanglement is well established and it has become increasingly apparent that all levels of biological organization (communities, organisms, cells, metabolism) consist of mosaics of interactive networks. There is a universe of bioactive microbial chemicals that have so far only been considered for their therapeutic applications; for example, the environmental roles of antibiotics have been little investigated. At sub-inhibitory concentrations, so-called antibiotics have been shown to modulate bacterial functions in subtle ways; they behave more like signals than toxins. It is proposed that networks of microbial cell signalling are primarily based on the interactions of low molecular weight compounds with macromolecular receptors; studies of the nature of these signals will reveal important information on the functions of microbial communities.