• Dyall, S.D. and Johnson, P.J. (2000). Origins of hydrogenosomes and mitochondria: evolution and organelle biogenesis. Current Opinion in Microbiology, 3 404–11.

Understanding the evolutionary history of mitochondria may reveal the origins of the eukaryotic cell.

• Nobelprize.org. (2012). The 2012 Nobel Prize in Physiology or Medicine—Advanced Information. www.nobelprize.org/nobel_prizes/medicine/laureates/2012/advanced.html

The science and significance of the 2012 Nobel prize award to John Gurdon and Shinya Yamanaka for their discovery that mature, differentiated cells can be reprogrammed to a pluripotent stem cell state.

• Villarreal, L. P. (2004). Are viruses alive? Sci. Am. 291, 100-105.

An interesting discussion of possible definitions of life and the significance of viruses.