  The sequence of nucleotide bases occurring in an organism's DNA is often
regarded as a codescript for its construction. However, information in a DNA
sequence can only be regarded as a codescript relative to an operational
biochemical machine, which the information constrains in such a way as to
direct the process of construction. In reality, any biochemical machine for
which a DNA codescript is efficacious is itself produced through the mechanical
interpretation of an identical or very similar codescript. In these terms the
origin of life can be described as a bootstrap process involving the
simultaneous accumulation of genetic information and the generation of a
machine that interprets it as instructions for its own construction. This
problem is discussed within the theoretical frameworks of thermodynamics,
informatics and self-reproducing automata, paying special attention to the
physico-chemical origin of genetic coding and the conditions, both
thermodynamic and informatic, which a system must fulfil in order for it to
sustain semiosis. The origin of life is equated with biosemiosis
