title: Microbial communities evolve faster in extreme environments.
abstract: 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.
authors.affiliation: 1] State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China [2].
authors.forename: Sheng-Jin
authors.initials: SJ
authors.lastname: Li
authors.affiliation: 1] State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China [2].
authors.forename: Zheng-Shuang
authors.initials: ZS
authors.lastname: Hua
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Li-Nan
authors.initials: LN
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Su-Hua
authors.initials: SH
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Lin-Xing
authors.initials: LX
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Jia-Liang
authors.initials: JL
authors.lastname: Kuang
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Biocontrol, Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education Institutes, College of Ecology and Evolution, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Shu
mesh_terms: D001105:Archaea / Q000235:genetics; D001419:Bacteria / Q000235:genetics; D016000:Cluster Analysis; D017753:Ecosystem; D019143:Evolution, Molecular; D059647:Gene-Environment Interaction; D019766:Genes, Archaeal; D005798:Genes, Bacterial; D045482:Hot Springs / Q000382:microbiology; D059013:Microbial Consortia / Q000235:genetics*; D056265:Microbial Interactions; D059645:Mutation Rate; D010802:Phylogeny; D014871:Water Microbiology