@article {2607,
	title = {On the Age and Origin of Lake Ejagham, Cameroon, and Its Endemic FishesAbstract},
	journal = {Quaternary Research},
	volume = {895716332765461461671825961727356647223},
	year = {2018},
	month = {Jan-01-2018},
	pages = {21 - 32},
	abstract = {Lake Ejagham is a small, shallow lake in Cameroon, West Africa, which supports five endemic species of cichlid fishes in two distinct lineages. Genetic evidence suggests a relatively young age for the species flocks, but supporting geologic evidence has thus far been unavailable. Here we present diatom, geochemical, mineralogical, and radiocarbon data from two sediment cores that provide new insights into the age and origin of Lake Ejagham and its endemic fishes. Radiocarbon ages at the base of the longer core indicate that the lake formed approximately 9 ka ago, and the diatom record of the shorter core suggests that hydroclimate variability during the last 3 millennia was similar to that of other lakes in Cameroon and Ghana. These findings establish a maximum age of ca. 9 cal ka BP for the lake and its endemic species and suggest that repeated cichlid speciation in two distinct lineages occurred rapidly within the lake. Local geology and West African paleoclimate records argue against a volcanic, chemical, or climatic origin for Lake Ejagham. Although not conclusive, the morphometry of the lake and possible signs of impact-induced effects on quartz grains are instead more suggestive of a bolide impact.},
	keywords = {Africa, cameroon, Cichlid, Diatom, evolution, Lake Ejagham, Speciation, West African monsoon},
	issn = {0033-5894},
	doi = {10.1017/qua.2017.37},
	url = {https://www.cambridge.org/core/product/identifier/S0033589417000370/type/journal_articlehttps://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589417000370},
	author = {Curt Stager, Jay and Alton, Kenneth and Martin, Christopher H. and King, David T. and Petruny, Lucille W. and Wiltse, Brendan and Livingstone, Daniel A.}
}
@article { ISI:000359186200001,
	title = {Phylogeny and phylogeography of functional genes shared among seven terrestrial subsurface metagenomes reveal N-cycling and microbial evolutionary relationships},
	journal = {FRONTIERS IN MICROBIOLOGY},
	volume = {5},
	year = {2014},
	month = {OCT 31},
	type = {Article},
	abstract = {Comparative studies on community phylogenetics and phylogeography of microorganisms living in extreme environments are rare. Terrestrial subsurface habitats are valuable for studying microbial biogeographical patterns due to their isolation and the restricted dispersal mechanisms. Since the taxonomic identity of a microorganism does not always correspond well with its functional role in a particular community, the use of taxonomic assignments or patterns may give limited inference on how microbial functions are affected by historical, geographical and environmental factors. With seven metagenomic libraries generated from fracture water samples collected from five South African mines, this study was carried out to (1) screen for ubiquitous functions or pathways of biogeochemical cycling of CH4, S, and N; (2) to characterize the biodiversity represented by the common functional genes; (3) to investigate the subsurface biogeography as revealed by this subset of genes; and (4) to explore the possibility of using metagenomic data for evolutionary study. The ubiquitous functional genes are NarV, NPD, PAPS reductase, NifH, NifD, NifK, NifE, and NifN genes. Although these eight common functional genes were taxonomically and phylogenetically diverse and distinct from each other, the dissimilarity between samples did not correlate strongly with geographical or environmental parameters or residence time of the water. Por genes homologous to those of Thermodesulfovibrio yellowstonii detected in all metagenomes were deep lineages of Nitrospirae, suggesting that subsurface habitats have preserved ancestral genetic signatures that inform the study of the origin and evolution of prokaryotes.},
	keywords = {evolution, functional genes, N-cycle, phylogenetics, phylogeny, phylogeography, terrestrial subsurface},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2014.00531},
	author = {Lau, Maggie C. Y. and Cameron, Connor and Magnabosco, Cara and Brown, C. Titus and Schilkey, Faye and Grim, Sharon and Hendrickson, Sarah and Pullin, Michael and Lollar, Barbara Sherwood and Van Heerden, Esta and Kieft, Thomas L. and Onstott, Tullis C.}
}
@article {2444,
	title = {A study of secondary organic aerosol formation in the anthropogenic-influenced southeastern United States},
	journal = {Journal of Geophysical Research-Atmospheres},
	volume = {112},
	year = {2007},
	note = {263D13302
},
	month = {Jul},
	abstract = {[1] The formation of secondary organic aerosol (SOA) in an anthropogenic-influenced region in the southeastern United States is investigated by a comparison with urban plumes in the northeast. The analysis is based on measurements of fine-particle organic compounds soluble in water (WSOC) as a measure of secondary organic aerosol. Aircraft measurements over a large area of northern Georgia, including the Atlanta metropolitan region, and in plumes from New York City and surrounding urban regions in the northeast show that fine-particle WSOC are spatially correlated with vehicle emission tracers (e.g., CO), yet the measurements indicate that vehicles do not directly emit significant particulate WSOC. In addition to being correlated, WSOC concentrations were in similar proportions to anthropogenic tracers in both regions, despite biogenic volatile organic compounds (VOCs) that were on average 10-100 times higher over northern Georgia. In contrast, radiocarbon analysis on WSOC extracted from integrated filters deployed in Atlanta suggests that roughly 70-80\% of the carbon in summertime WSOC is modern. If both findings are valid, the combined results indicate that in northern Georgia, fine-particle WSOC was secondary and formed through a process that involves mainly modern biogenic VOCs but which is strongly linked to an anthropogenic component that may largely control the mass of SOA formed. Independent of the radiocarbon results, a strong association between SOA and anthropogenic sources has implications for control strategies in urban regions with large biogenic VOC emissions.},
	keywords = {AMBIENT AEROSOL, atmosphere, C-14, emissions, evolution, GASOLINE, OXIDATION, PARTICLES, RATIOS, ZURICH},
	isbn = {2169-897X},
	doi = {10.1029/2007JD008408},
	author = {Weber, R. J. and Sullivan, A. P. and Peltier, R. E. and Russell, A. and Yan, B. and Zheng, M. and de Gouw, J. and Warneke, C. and Brock, C. and Holloway, J. S. and Atlas, E. L. and Edgerton, E.}
}
@article {2094,
	title = {Precambrian marine carbonate isotope database: Version 1.1},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {3},
	year = {2002},
	note = {561enTimes Cited:103
Cited References Count:26
},
	month = {Jun 6},
	pages = {1-12},
	abstract = {[1] We present a compilation of strontium, carbon, and oxygen isotope compositions of roughly 10,000 marine carbonate rocks of Archean - Ordovician age (3800 Ma - 450 Ma). The Precambrian Marine Carbonate Isotope Database (PMCID) has been compiled from 152 published and 3 unpublished articles and books of the past 40 years. Also included are 30 categories of relevant "metadata{\textquoteright}{\textquoteright} that allow detailed comparisons and quality assessments of the isotope data to be made. The PMCID will be updated periodically as new data and better age constraints come to light. Here we outline the structure of the first published version of the database and its inherent merits and limitations.},
	keywords = {1010 geochemistry : chemical evolution, 1030 geochemistry : geochemical cycles (0330), 1040 geochemistry : isotopic composition/chemistry, 1050 geochemistry : marine geochemistry (4835,4850), calcite, carbonates, cycle, dolomite, evolution, Geochemistry, isotope stratigraphy, oceans, precambrian, SEAWATER, sediments, strontium, sulfur, time},
	isbn = {1525-2027},
	doi = {10.1029/2001GC000266},
	author = {Shields, G. and Veizer, J.}
}
@article {2118,
	title = {Volcanic gases, black smokers, and the Great Oxidation Event},
	journal = {Geochimica Et Cosmochimica Acta},
	volume = {66},
	year = {2002},
	note = {608ztTimes Cited:295
Cited References Count:57
},
	month = {Nov},
	pages = {3811-3826},
	abstract = {This paper proposes that gradual changes in the composition of volatiles that have been added to the atmosphere-ocean system are responsible for the Great Oxidation Event (G.O.E.) ca. 2.3 Ga. Before ca. 2.3 Ga, the composition of these volatiles was probably such that 20\% of the carbon gases could be reduced to organic matter and all of the sulfur gases could be reduced to pyrite. Since 2.3 Ga, the composition of these volatiles has been such that 20\% of the carbon gases could be reduced to organic matter, but only a fraction of the sulfur gases could be reduced to pyrite. This change led to the oxygenation of the atmosphere and to a large increase in the SO4-2 concentration of seawater. A considerable body of observational data supports these proposals. Copyright (C) 2002 Elsevier Science Ltd.},
	keywords = {atmospheric oxygen, carbon, chemistry, east pacific rise, evolution, hydrothermal vent fluids, midocean ridges, precambrian cherts, south-africa, sulfur cycle},
	isbn = {0016-7037},
	doi = {10.1016/S0016-7037(02)00950-X},
	author = {Holland, H. D.}
}
