caa a22 4500 445820829 CHVBK 20180317145243.0 cr unu---uuuuu 170323e20111001xx s 000 0 eng 10.1007/s00239-011-9467-y doi (NATIONALLICENCE)springer-10.1007/s00239-011-9467-y Blank Carrine Department of Geosciences, University of Montana, 32 Campus Drive #1296, 59812-1296, Missoula, MT, USA aut An Expansion of Age Constraints for Microbial Clades that Lack a Conventional Fossil Record Using Phylogenomic Dating [Elektronische Daten] [Carrine Blank] Most microbial taxa lack a conventional microfossil or biomarker record, and so we currently have little information regarding how old most microbial clades and their associated traits are. Building on the previously published oxygen age constraint, two new age constraints are proposed based on the ability of microbial clades to metabolize chitin and aromatic compounds derived from lignin. Using the archaeal domain of life as a test case, phylogenetic analyses, along with published metabolic and genetic data, showed that members of the Halobacteriales and Thermococcales are able to metabolize chitin. Ancestral state reconstruction combined with phylogenetic analysis of the genes underlying chitin degradation predicted that the ancestors of these two groups were also likely able to metabolize chitin or chitin-related compounds. These two clades were therefore assigned a maximum age of 1.0Ga (when chitin likely first appeared). Similar analyses also predicted that the ancestor to the Sulfolobus solfataricus-Sulfolobus islandicus clade was able to metabolize phenol using catechol dioxygenase, so this clade was assigned a maximum age of 475Ma. Inferred ages of archaeal clades using relaxed molecular clocks with the new age constraints were consistent with those inferred with the oxygen age constraints. This work expands our current toolkit to include Paleoproterozoic, Neoproterozoic, and Paleozoic age constraints, and should aid in our ability to phylogenetically reconstruct the antiquity of a wide array of microbial clades and their associated morphological and biogeochemical traits, spanning deep geologic time. Such hypotheses—although built upon evolutionary inferences—are fundamentally testable. Springer Science+Business Media, LLC, 2011 Archaea nationallicence Microbial evolution nationallicence Phylogenomic dating nationallicence Relaxed molecular clock nationallicence Chitinase nationallicence Chitin degradation nationallicence Lignin degradation nationallicence ASR : Ancestral character state reconstruction nationallicence Ga : Giga-anna (billion years) before present nationallicence Ma : Mega-anna (million years) before present nationallicence MB : Mr. Bayes, Bayesian method of phylogenetic reconstruction nationallicence MP : Maximum parsimony method of phylogenetic reconstruction nationallicence RMC : Relaxed molecular clock nationallicence Journal of Molecular Evolution Springer-Verlag 73/3-4(2011-10-01), 188-208 0022-2844 73:3-4<188 2011 73 239 https://doi.org/10.1007/s00239-011-9467-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00239-011-9467-y text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Blank Carrine Department of Geosciences, University of Montana, 32 Campus Drive #1296, 59812-1296, Missoula, MT, USA aut NATIONALLICENCE 773 0- Journal of Molecular Evolution Springer-Verlag 73/3-4(2011-10-01), 188-208 0022-2844 73:3-4<188 2011 73 239 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer