The archaeology of apoptosis.
Human death has been recognised as a significant personal and social event for many thousands of years, and classical archaeologists have revealed the changing complexity of rituals associated with it. The study of cell death, however, is a much more recent event, although many of the molecular pathways involved have now been identified, at least in mammalian systems. In studying the loss of cells, the use of the term 'death' is, perhaps, not altogether appropriate both since it carries the cultural resonance associated with bodily death, and because we do not study cell death itself, but rather the processes that lead up to it. Mammalian cell death processes are complex and involve a dynamic equilibrium between death promoting and death inhibiting factors, suggesting that some components of death pathways may have a paradoxical survival function. Since parasites must survive an often hostile environment, they may be a useful model to study whether component molecules of mammalian death pathways originally formed modules of parasite survival strategies, and whether survival and death pathways coevolved.