Following Pasteur's refutation of Spontaneous Generation, the idea
of Panspermia gained some credibility for a while. This theory,
which proposes that life is an inherent property of the Universe and
that it arrived on Earth fom space, is covered in more detail in the
discussion of the 'Earth Or Space' issue.
A number of criticisms of the theory were raised, but at the turn
of the century it seemed to be the only plausible explanation
for the Origin of Life. Then, in the 1920s, an alternative
'Primordial Soup' theory was put forward by Oparin and
Haldane. This is discussed in the page on the Oparin-Haldane
Later, two key events in the mid twentieth century set the
framework for much of the research into the origin of life that
has taken place since. These were:-
The Miller-Urey experiment: This was an attempt to reproduce
the kind of processes that would have ocurred in the
Watson and Crick's discovery of the structure of DNA.
Each of these also has a page in the 'Landmarks' section.