20
B
efore the 18th century, most
people believed that plant
and animal species stayed
unchanged throughout time—a view
now known as essentialism. This
idea came under challenge as a
result of two developments: the
intellectual movement known as the
Enlightenment (c. 1715 –180 0), and
the Industrial Revolution (1760–1840).
The Enlightenment was marked
by scientific progress and increased
questioning of religious orthodoxy,
such as the claim that God created
Earth and all living things in seven
days. Then, as the Industrial
Revolution gathered pace, canals,
railroads, mines, and quarries
cut through rock strata and revealed
thousands of fossils, mostly of
animal and plant species that no
longer existed and had never been
seen before. These suggested that
life began long before the widely
accepted creation date of 4400 bce,
deduced from biblical sources.Animal adaptation
In the late 1700s, French scientist
Georges-Louis Leclerc, Comte de
Buffon, upset church authorities
by asserting that Earth was much
older than the Bible suggested. He
believed it was formed from moltenmaterial, struck off the Sun by a
comet, that had taken 70,000 years
to cool (a huge underestimate, in
fact). As Earth cooled, species had
appeared, died off, and were finally
replaced by ancestors of those
known today. Noting similarities
among animals such as lions,
tigers, and cats, Buffon deduced
that 200 species of quadrupeds had
evolved from just 38 ancestors. He
also believed that changes in body
shape and size in related species
had occurred in response to living
in different environments.
In 1800, French naturalist Jean-
Baptiste Lamarck went further. In a
lecture at the Museum of NaturalIN CONTEXT
KEY FIGURES
The Comte de Buffon
(1707–88), Jean-Baptiste
Lamarck (174 4 –1829)BEFORE
1735 Swedish botanist Carl
Linnaeus publishes Systema
Naturae, a system of biological
classification that later helped
to determine species’ ancestry.1751 In “Système de la nature”
French philosopher Pierre
Louis Moreau de Maupertuis
introduces the idea that
features can be inherited.AFTER
1831 Etienne Geoffroy Saint-
Hilaire writes that sudden
environmental change can
cause a new species to develop
from an existing organism.1844 In Vestiges of the Natural
History of Creation, Scottish
geologist Robert Chambers
argues—anonymously—that
simple creatures have evolved
into more complex species.TIME IS INSIGNIFICANT,
AND NEVER A DIFFICULTY
FOR NATURE
EARLY THEORIES OF EVOLUTIONNature is the system of laws
established by the Creator for
the existence of things and
for the succession of creatures.
The Comte de BuffonUS_020-021_Early_theories.indd 20 12/11/18 6:24 PM