  The theory of cometary panspermia, developed by the late Sir Fred Hoyle and
the present author argues that life originated cosmically as a unique event in
one of a great multitude of comets or planetary bodies in the Universe. Life on
Earth did not originate here but was introduced by impacting comets, and its
further evolution was driven by the subsequent acquisition of cosmically
derived genes. Explicit predictions of this theory published in 1979-1981,
stating how the acquisition of new genes drives evolution, are compared with
recent developments in relation to horizontal gene transfer, and the role of
retroviruses in evolution. Precisely-stated predictions of the theory of
cometary panspermia are shown to have been verified.
