Microbial communities evolve faster in extreme environments

• Published in: Scientific reports Vol. 4; no. 1; p. 6205
• Main Authors: Li, Sheng-Jin, Hua, Zheng-Shuang, Huang, Li-Nan, Li, Jie, Shi, Su-Hua, Chen, Lin-Xing, Kuang, Jia-Liang, Liu, Jun, Hu, Min, Shu, Wen-Sheng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.08.2014; Nature Publishing Group
• Subjects: 45; 45/23; 45/47; 631/158/853; 631/181; 631/181/735; Acid mine drainage; Adaptation; Archaea - genetics; Bacteria - genetics; Benign; Biodiversity; Cluster Analysis; Ecosystem; Environmental conditions; Evolution; Evolution, Molecular; Gene-Environment Interaction; Genes, Archaeal; Genes, Bacterial; Genomes; Habitats; Hot springs; Hot Springs - microbiology; Humanities and Social Sciences; Laboratories; Microbial activity; Microbial Consortia - genetics; Microbial Interactions; Microbiomes; multidisciplinary; Mutation; Mutation Rate; Mutation rates; Natural environment; Phylogenetics; Phylogeny; Salt lakes; Science; Water Microbiology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep06205

Evolutionary analysis of microbes at the community level represents a new research avenue linking ecological patterns to evolutionary processes, but remains insufficiently studied. Here we report a relative evolutionary rates (rERs) analysis of microbial communities from six diverse natural environments based on 40 metagenomic samples. We show that the rERs of microbial communities are mainly shaped by environmental conditions and the microbes inhabiting extreme habitats (acid mine drainage, saline lake and hot spring) evolve faster than those populating benign environments (surface ocean, fresh water and soil). These findings were supported by the observation of more relaxed purifying selection and potentially frequent horizontal gene transfers in communities from extreme habitats. The mechanism of high rERs was proposed as high mutation rates imposed by stressful conditions during the evolutionary processes. This study brings us one stage closer to an understanding of the evolutionary mechanisms underlying the adaptation of microbes to extreme environments.