158. M.M. Moeseneder, J.M. Arrieta, G. Muyzer, C. Winter, and G.J. Herndl, “Optimization of Terminal-restriction Fragment Length Polymorphism Analysis for Complex Marine Bacterioplankton Communities and Comparison with Denaturing Gradient Gel Electrophoresis,” Appl. Environ. Microbiol. 65:3518-3525, 1999.

159. D.A. Stahl and R. Amann, “Development and Application of Nucleic Acid Probes in Bacterial Systematics, ” in Sequencing and Hybridization Techniques in Bacterial Systematics, E. Stackebrandt and M. Goodfellow (eds.), John Wiley and Sons, Chichester, U.K., 1991, pp. 205-248.

160. R.I. Amann, W. Ludwig, and K.-H. Schleifer, “Phylogenetic Identification and In Situ Detection of Individual Microbial Cells Without Cultivation,” Microbiol. Rev. 59:143-169, 1995.

161. E.F. DeLong, G.S. Wickham, and N.R. Pace, “Phylogenetic Stains: Ribosomal RNA-based Probes for the Identification of Single Cells,” Science 243:1360-1363, 1989.

162. R.I. Amann, W. Ludwig, and K.-H. Schleifer, “Phylogenetic Identification and In Situ Detection of Individual Microbial Cells Without Cultivation,” Microbiol. Rev. 59:143-169, 1995.

163. D.A. Stahl, “Application of Phylogenetically Based Hybridization Probes to Microbial Ecology,” Mol. Ecol. 4:535-542, 1995.

164. D.A. Stahl and R. Amann, “Development and Application of Nucleic Acid Probes in Bacterial Systematics, ” in Sequencing and Hybridization Techniques in Bacterial Systematics, E. Stackebrandt and M. Goodfellow (eds.), John Wiley and Sons, Chichester, England, 1991, pp. 205-248.

165. H. Hennecke, K. Kaluza, B. Thony, M. Fuhrmann, W. Ludwig, and E. Stackebrandt, “Concurrent Evolution of Nitrogenase Genes and 16S rRNA in Rhizobium Species and Other Nitrogen-fixing Bacteria,” Arch. Microbiol. 142:342-348, 1985.

166. C. Wawer and G. Muyzer, “Genetic Diversity of Desulfovibrio spp. in Environmental Samples Analyzed by Denaturing Gradient Gel Electrophoresis of [NiFe] Hydrogenase Gene Fragments,” Appl. Environ. Microbiol. 61:2203-2210, 1995.

167. M. Wagner, A.J. Roger, J.L. Flax, G.A. Brusseau, and D.A. Stahl, “Phylogeny of Dissimilatory Sulfite Reductases Supports an Early Origin of Sulfate Respiration,” Journal Bacteriol. 180:2975-2982, 1998.

168. D. Minz, J.L. Flax, S.J. Green, G. Muyzer, Y. Cohen, M. Wagner, B.E. Rittmann, and D.A. Stahl, “Diversity of Sulfate-reducing Bacteria in Oxic and Anoxic Regions of a Microbial Mat Characterized by Comparative Analysis of Dissimilatory Sulfite Reductase Genes,” Appl. Environ. Microbiol. 65:4666-4671, 1999.

169. D.M. Karl, D.F. Bird, K. Bjorkman, T. Houlihan, R. Shackelford, and L. Tupas, “Microorganisms in the Accreted Ice of Lake Vostok, Antarctica,” Science 286:2144-2147, 1999.

170. N.R. Pace, B.C. Thomas, and C.R. Woese, “Probing RNA Structure, Function, and History by Comparative Analysis, ” in The RNA World: The Nature of Modern RNA Suggests a Prebiotic RNA, R.F. Gesteland, T.R. Cech, and J.F. Atkins (eds.), 2nd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1999, pp. 79-112.

171. N.R. Pace, “Origin of Life—Facing Up to the Physical Setting,” Cell 65:531-533, 1991.

172. S.M. Barns, R.E. Fundyga, M.W. Jeffries, and N.R. Pace, “Remarkable Archaeal Diversity Detected in a Yellowstone National Park Hot Spring Environment,” Proc. Natl. Acad. Sci. USA 91:1609-1613, 1994.

173. S.M. Barns, R.E. Fundyga, M.W. Jeffries, and N.R. Pace, “Remarkable Archaeal Diversity Detected in a Yellowstone National Park Hot Spring Environment,” Proc. Natl. Acad. Sci. USA 91:1609-1613, 1994.

174. W.L. Nicholson, N. Munakata, G. Horneck, H.J. Melosh, and P. Setlow, “Resistance of Bacillus Endospores to Extreme Terrestrial and Extraterrestrial Environments,” Microbiol. Mol. Biol. Rev. 64:548-572, 2000.

175. C. Mileikowsky, F.A. Cucinotta, J.W. Wilson, B. Gladman, G. Horneck, L. Lindegren, J. Melosh, H. Rickman, M. Valtonen, and J.Q. Zheng, “Natural Transfer of Viable Microbes in Space. 1. From Mars to Earth and Earth to Mars,” Icarus 145:391-427, 2000.

176. J.W. Valley, J.M. Eiler, C.M. Graham, E.K. Gibson, C.S. Romanek, and E.M. Stolper, “Low-temperature Carbonate Concretions in the Martian Meteorite ALH84001: Evidence from Stable Isotopes and Mineralogy,” Science 275:1633-1638, 1997.

177. E.R. Scott, A. Yamaguchi, and A.N. Krot, “Petrological Evidence for Shock Melting of Carbonates in the Martian Meteorite ALH84001,” Nature 387:377-379, 1997.

178. S.J. Mojzsis, R. Krishnamurthy, and G. Arrhenius, “Before RNA and After: Geophysical and Geochemical Constraints on Molecular Evolution,” in The RNA World: The Nature of Modern RNA Suggests a Prebiotic RNA , R.F. Gesteland, T.R. Cech, and J.F. Atkins (eds.), 2nd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1999, pp. 1-48.

179. K.S. Makarova, L. Aravind, M.Y. Galperin, N.V. Grishin, R.L. Tatusov, Y.I. Wolf, and E.V. Koonin, “Comparative Genomics of the Archaea (Euryarchaeota): Evolution of Conserved Protein Families, the Stable Core, and the Variable Shell, ” Genome Research 9:608-628, 1999.

180. P.D. Ward and D. Brownlee, Rare Earth: Why Complex Life Is Uncommon in the Universe, Copernicus, New York, 2000.

181. W.L. Nicholson, N. Munakata, G. Horneck, H.J. Melosh, and P. Setlow, “Resistance of Bacillus Endospores to Extreme Terrestrial and Extraterrestrial Environments,” Microbiol. Mol. Biol. Rev. 64:548-572, 2000.

182. K. Pedersen, “Exploration of Deep Intraterrestrial Microbial Life: Current Perspectives, ” FEMS Microbiol. Lett. 185:9-16, 2000.

183. M.C. Malin and K.S. Edgett, “Evidence for Recent Groundwater Seepage and Surface Runoff on Mars, ” Science 288:2330-2335, 2000.

184. M.C. Malin, A. McEwen, M. Carr, L. Soderblom, P. Thomas, E. Danielson, P. James, J. Veverka, and W.K. Hartmann, “Evidence for Recent Volcanism on Mars from Crater Counts,” Nature 397:586-589, 1999.