Ultrashort processes and biology

An attempt is made to answer the question 'Have we reached the temporal bou ndaries of biology?' In the author's opinion, which is based largely on exp erience with early events in photosynthesis, the answer depends on the time scale on which processes highly specific to life can be identified, thus, to a large extent on definitions rather than on the possibilities afforded by technological development. Bohr's "complementarity principle for living systems" is discussed in this context. (C) 1999 Elsevier Science S.A. All r ights reserved.