A
ncient myths, religions, and
philosophies all reflect an
enduring fascination with
how the world began and man’s
place in the story of life on Earth. In
the West, Christianity held that all
animals and plants were the result
of a perfect creation. On the chain
or ladder of being, no species could
ever move from one position to
another. Species were immutable,
an idea called essentialism.
The 18th-century Age of
Enlightenment began to challenge
orthodox Christian beliefs. French
zoologist Jean-Baptiste Lamarck
rejected the prevailing Bible-based
notion of Earth being only a few
thousand years old. He argued that
organisms must have changed from
simple life forms to more complex
ones over millions of years, and that
the “transmutation” of specieswas the driving force behind this
change. He speculated that
characteristics acquired by animals
during their lifetime were inherited
by the next generation: giraffes, for
example, became slightly longer-
necked by stretching up to reach
higher leaves, and passed this trait
to their offspring; over many
generations, giraffes grew longer
and longer necks.
Fossil evidence of extinct life
forms with features that resembled
modern descendants, found by
pioneering geologists such as
Georges Cuvier, also suggested
Earth had more ancient origins.
Meanwhile James Hutton and
Charles Lyell argued that geological
features could be accounted for by
the constant, ongoing processes
of erosion, and deposition—a view
called uniformitarianism. Becausethese processes take place slowly,
Earth’s history had to be much
longer than was previously thought.Natural selection
In 1858, Charles Darwin and Alfred
Russel Wallace delivered a paper
that would change biology forever.
Darwin’s observations on the epic
voyage of the Beagle (1831–36),
his correspondence with other
naturalists, and the influence
of Thomas Malthus’s writings
inspired Darwin’s insight that
evolution came about by what he
called natural selection. He spent
20 years gathering supporting data,
but when Wallace wrote to him
with the same idea, Darwin
realized it was time to go public.
His subsequent book, On the
Origin of Species by Means of
Natural Selection, provoked outrage.INTRODUCTION
1785
James Hutton presents
his theory that Earth is
much older than was
previously believed, and
that Earth’s crust is
continuously changing.1813
In his Essay on the Theory
of the Earth, Georges Cuvier
suggests that fossils are the
remains of extinct creatures
wiped out by periodic
“catastrophic” events.1831
HMS Beagle sets sail on a
circumnavigation of the world, with
Charles Darwin serving as the
voyage’s naturalist. The trip provides
Darwin with the information that
inspired his theory of evolution
by natural selection.1809
Jean-Baptiste Lamarck
publishes Philosophie Zoologique,
where he argues that animals acquire
characteristics as a consequence of
use or nonuse of different body parts,
triggering mutations over generations.1823
Amateur fossil
hunter Mary Anning
uncovers the first intact
plesiosaurus skeleton.18
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