Further reading Conover, Emily. (2015) 'Shadow biosphere' might be hiding strange life right under our noses, Science News, Science Cleland, C.E. (2006) Astrobiology Magazine A Shadow Biosphere Cleland, C.E. (2007) Epistemological issues in the study of microbial life: alternative biospheres. Studies in the History and Philosophy of Biological and Biomedical Sciences 38:847–861. Cleland, C. E. and Copley, S. D. (2005) The possibility of alternative microbial life on Earth. International Journal of Astrobiology 4(4), 165–173. Davies, P. C. W., Lineweaver, C. H., Finding a Second Sample of Life on Earth, Astrobiology, vol. 5, no. 2, 2005, doi=10.1089/ast.2005.5.154 Wolfe-Simon,F., Davies,P.C.W. and Anbar, A.D. (2009) Did nature also choose arsenic? International Journal of Astrobiology, Cambridge University Press Pace, N. R. (1997) A molecular view of microbial diversity and the biosphere. Science, 274, 734–740. Woese, C. R. (2004) The archaeal concept and the world it lives in: a retrospective. Photosynthesis Research, 80, 361–372. External links A Shadow Biosphere Bacteria stir debate about 'shadow biosphere' Alternate "Life" Styles: Scientists Predict The Possibility Of A Shadow Biosphere Astrobiology Ecology Philosophy of biology Hypothetical life forms