Evolution, microbial

In summary, then, conjugation is a natural process representing the early stages in a true sexually reproduetive proeess. Transformation involving autolysis of the culture with loss of genetic material, and transduetion arising out of an infective process, are seeondary processes whieh are not known to occur in eukaryotes nevertheless, they must have taken their part in microbial evolution. 

Bayly R, R Jain, CL Poh, R Skurry (1988) Unity and diversity in the degradation of xylenols by Pseudomonas spp. a model for the study of microbial evolution. In Microbial Metabolism and the Carbon Cycle (Eds SR Hagedorn, RS Hanson, DA Kunz) pp. 359-379. Harwood Academic Publishers, Chur, Switzerland. 

I. K. Jordan E. V. Koonin, Horizontal Gene Transfer and Prokaryotic Genome Evolution. In Microbial Evolution Gene Establishment, Survival, and Exchange R. V. Millner, M. J. Day, Eds. ASM Press Washington, DC, 2004 pp 319-338. 

Cavalier-Smith, T. (1981) in Molecular and Cellular Aspects of Microbial Evolution (Carlisle, M.J., Collins, J.F. and Moseley, B.E.B., eds.) pp. 33-84, Cambridge University Press, Cambridge. 

Studies were conducted at Gulf Research Development Company by Janezic (1979) to investigate the anaerobic microbial evolution of C -C hydrocarbons upon decomposition of various organic substrates including green plant branches, grass... 

Fig. 5-5. Anaerobic microbial evolution of CH4 upon decomposition of various organic substrates.

Arroyo Lopez, F.N., Duran Quintana, M.C., and Garrido, F.A. 2006. Microbial evolution during storage of seasoned olives prepared with organic acids with potassium sorbate, sodium benzoate, and ozone used as preservatives. Journal of Food Protection 69 1354—1364. 

The origin of life and its evolution into the life-forms we know today remains a contentious issue. This controversy arises mainly because there is a lack of hard scientific data, from fossils or other sources, on how primitive cells develop (microbial evolution being about as far back as we can go). Cosmology and geochemical data suggest that the Earth was formed as a condensation product from gas and dust particles from an immense supernova in outer space some (4.5-4.7) X 10 years ago. 

So, regardless of the specific sequence of cycles in microbial evolution itself, it is clear that microbial activity have changed the chemical composition of atmosphere. Though changes in atmospheric composition have been tremendous, especially to the extent of oxygen content from < 0.001% to > 20.9%, they have typically been very gradual. We have to consider periods of a hundred million years or even a billion years when we are discussing evolution of the atmosphere. 

Full appreciation of microbial evolution must come from a complete knowledge of extant microbial diversity. As well, full appreciation of microbial diversity can only come from an understanding of their evolution. Although these studies generally have been treated independently, this is mostly because there has been no unifying conceptual and technical framework. The ribosomal RNAs now provide the framework. They therefore offer the criteria to explicitly characterize any organism on this planet and to place it in a phylogenetic context. They can be used to characterize natural communities without the requirements of cultivation or previous pure-culture descriptions of the community members (7,10). 

Margulis, L. and Sagan, D. Microcosmos. Four Billion Years of Microbial Evolution. 

Bilinski, T. Oxygen toxicity and microbial evolution. Biosystems 24 305-312 1991. 

Gatti, M, Bottari, B., Lazzi, C., Neviani, E. et cd. (2014) Invited review microbial evolution in raw-milk, long-ripened cheeses produced using undefined mt-ural whey starters. J. Dairy ScL, 97, 573-591. 

The utilization of H2 in metabolic chemistry has remained a common thread throughout the long history of microbial evolution. The increasing complexity of individual organisms and microbial ecosystems has been mirrored by an increasing complexity in the role played by H2. Successive biochemical advances have often retained and expanded on earlier aspects of H2 metabolism. This continuity and expansion in the microbial utilization of H2 corresponds to a continually evolving role for H2 in the biogeochemistry of the Earth. 

Lynn Margulis is a Distinguished University Professor at the University of Massachusetts. She has made original contributions to cell biology and microbial evolution to developing science teaching materials and hands-on garbage and trash projects in elementary schools. 

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