In his book, Darwin never mentioned the origin
of life. The primitive understanding of science in his time
rested on the assumption that living things had very simple
structures. Since mediaeval times, spontaneous generation,
the theory that non-living matter could come together to
form living organisms, had been widely accepted. It was
believed that insects came into existence from leftover
bits of food. It was further imagined that mice came into
being from wheat. Interesting experiments were conducted
to prove this theory. Some wheat was placed on a dirty piece
of cloth, and it was believed that mice would emerge in
Louis Pasteur destroyed
the belief that life could be created from inanimate
Similarly, the fact that maggots appeared in
meat was believed to be evidence for spontaneous generation.
However, it was only realized some time later that maggots
did not appear in meat spontaneously, but were carried by
flies in the form of larvae, invisible to the naked eye.
Even in the period when Darwin's Origin of
Species was written, the belief that bacteria could come
into existence from inanimate matter was widespread.
However, five years after
the publication of Darwin's book, Louis Pasteur announced
his results after long studies and experiments, which disproved
spontaneous generation, a cornerstone of Darwin's theory.
In his triumphal lecture at the Sorbonne in 1864, Pasteur
said, "Never will the doctrine of spontaneous generation
recover from the mortal blow struck by this simple experiment."2
Advocates of the theory of evolution refused
to accept Pasteur's findings for a long time. However, as
scientific progress revealed the complex structure of the
cell, the idea that life could come into being coincidentally
faced an even greater impasse. We shall consider this subject
in some detail in this book.