The Golden Age of Molecular Ecology

Abstract

The observations of different organisms’ interactions with their environment and with each other can probably be extended back to prehistoric times when humans became inquisitive about the conditions in which they lived and survived. This process became more “scientific” in Ancient Greece, when great philosophers of the time such as Aristotle, Hippocrates, and Herodotus provided first written evidence and descriptions of nature and the observable interactions among different animals and plants [1]. By now, while still a relatively young discipline, ecology has developed into a complex science that encompasses analyses of ecosystem biodiversity, spatial and temporal species distribution and dynamic fluctuation, cross-species interactions, and evolutionary processes in the environment. While the original ecological studies have been based on direct observation, the ecological disciplines have gradually involved the use of DNA and protein sequences in the evaluation of environmental diversity, community composition, evolutionary relationships, and species taxonomy. The use of molecular analyses has seen the largest impact in two areas, those of phylogenetic and biodiversity assessments. In both cases, by utilizing the general principle of molecular sequence conservation and gradual mutation over time, we can evaluate evolutionary relationships among species as well as reveal species identities by only analyzing select few DNA (or sometimes protein) sequences from each organism. Thus, current systematics and taxonomy no longer need to rely on the observations of species morphological and physiological characteristics but can rather use molecular phylogenetic information. Similarly, ecosystem biodiversity measurements should no longer have to rely on an exhaustive description and direct detection of all ecosystem inhabitants, but can rather employ DNA analysis to reveal who is present. The latter approach is especially effective for the studies of microbial communities, where cultivating and examining separately all individual members of the community is in many cases not practical.