1. Lamarck, J. -B. Histoire Naturelle des Animaux sans Vertèbres (Verdière, Paris, 1815).
2. Darwin, C. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (John Murray, London, 1859).
3. Darwin, C. Charles Darwin's Notebooks, 1836–1844 (Cornell University Press, Ithaca, 1987). Annotated version of Darwin's notebooks, including facsimiles of many pages. Gives an insight into Darwin's thoughts as he formulated the idea of evolution by natural selection.
4. Gogarten, J. P. & Olendzenski, L. Orthologs, paralogs and genome comparisons. Curr. Opin. Genet. Dev. 9, 630–636 (1999).
5. Ehrenreich, A. & Widdel, F. Anaerobic oxidation of ferrous iron by purple bacteria, a new type of phototrophic metabolism. Appl. Environ. Microbiol. 60, 4517–4526 (1994).