A CENTURY AGO, 1858, Charles Darwin and Alfred Russel
Wallace jointly announced to the Linnean Society of London
their independent discovery of natural selection as the method of
evolution. And the following year, in 1859, Charles Darwin pub-
lished his famous classic, Origin of Species.

Countries over the world today are celebrating the centenary
of these events and honoring Darwin and his book as the beginning
of new biological thought.

The University of Pittsburgh Press publishes the five essays in
this book as its share in this important centenary celebration.

Each essay has been written by a specialist in an individual
field of interest and study affected by Darwin's book. Each is a
man of distinction in today's world of research and thought. Each
writes to show the effect of the publication of Darwin Origin of
Species on his own field.

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