Here is one biologist's interpretation of the chronology of life during
the last six hundred million years of earth history: an extended essay
that draws on the author's own data and a wide-ranging literature survey
to discuss the nature and dynamics of evolutionary change in organisms
and their biological surroundings. Geerat Vermeij demonstrates that
escalation--the process by which species adapt to, or are limited by,
their enemies as the latter increase in ability to acquire and retain
resources--has been a dominant theme in the history of life despite
frequent episodes of extinction.